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Roberta Iatta
Ruolo
Ricercatore a tempo determinato - tipo B
Organizzazione
Università degli Studi di Bari Aldo Moro
Dipartimento
DIPARTIMENTO DI MEDICINA VETERINARIA
Area Scientifica
AREA 07 - Scienze agrarie e veterinarie
Settore Scientifico Disciplinare
VET/06 - Parassitologia e Malattie Parassitarie degli Animali
Settore ERC 1° livello
Non Disponibile
Settore ERC 2° livello
Non Disponibile
Settore ERC 3° livello
Non Disponibile
Microbial colonization and biofilm formation on implanted devices represent an important complication in orthopaedic and dental surgery and may result in implant failure. Controlled release of antibacterial agents directly at the implant site may represent an effective approach to treat these chronic complications. Resistance to conventional antibiotics by pathogenic bacteria has emerged in recent years as a major problem of public health. In order to overcome this problem, non-conventional antimicrobial agents have been under investigation. In this study, polyacrylate-based hydrogel thin coatings have been electrosynthesised on titanium substrates starting from poly(ethylene glycol diacrylate)–co– acrylic acid. Silver nanoparticles (AgNPs) with a narrow size distribution have been synthesized using a “green” procedure and immobilized on Ti implant surfaces exploiting hydrogel coatings’ swelling capabilities. The coatings have been characterized by XPS and SEM/EDX, while their silver release performances have been monitored by ICP–MS. The antibacterial activity of these AgNP-modified hydrogel coatings was tested evaluating in vitro inhibition growth of Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli, among the most common pathogens in orthopaedic infections. Moreover, a preliminary investigation of the biocompatibility of silver-loaded coatings versus MG63 human osteoblast-like cells has been performed. An important point of strength of this paper, in fact, is the concern about the effect of silver species on the surrounding cell system in implanted medical devices. Silver ion release has been properly tuned in order to assure antibacterial activity while preserving osteoblasts’ response
Nosocomial yeast infections have increased significantly worldwide and especially in surgical and intensive care unit (ICU) patients. Although Candida species have various degrees of susceptibility to frequently used drugs, antifungal resistance is rare. A ten-year retrospective surveillance of candidemia was carried out in a University Hospital of Southern Italy. The aim of this study was the determination of Candida bloodstream infections (BSI) and central venous catheter (CVC)-related episodes, prevalence and in vitro susceptibility. 320 candidemia episodes were registered and 374 yeasts collected. Etest and Sensititre methods were used to test the isolates' susceptibility to amphotericin B, anidulafungin, caspofungin, fluconazole, itraconazole, posaconazole and voriconazole. The results were compared with those of CLSI reference broth microdilution method. Most yeasts were susceptible to all antifungal drugs, with the exception of C. glabrata susceptibility to triazoles and C. tropicalis to fluconazole and voriconazole. As expectedC. parapsilosis isolates were generally associated with higher echinocandin minimum inhibitory concentrations (MICs) than the other Candida species. This study confirms the different antifungal susceptibility patterns among species, and underlines the need to perform antifungal susceptibility testing of clinically relevant yeasts.
The microdilution antifungal method (CLSI BMD, M27-A3) was used for testing the antifungal susceptibility of Malassezia species. However, optimal broth media that allow sufficient growth of M. pachydermatitis and produce reliable and reproducible MICs using the CLSI BMD protocol are yet to be established. In this study, the susceptibility of M. pachydermatis isolates to ketoconazole (KTZ), itraconazole (ITZ) and fluconazole (FLZ) was evaluated in vitro by the CLSI BMD test using Christensen's urea broth (CUB) and mRPMI 1640 containing lipid supplementation, Sabouraud dextrose broth with 1% tween 80 (SDB), and Dixon broth (DXB). A FLZ-resistant M. pachydermatis was generated in vitro and tested under the same conditions. A good growth of M. pachydermatis incubated for 48 and 72h, respectively, was observed in CUB, SDB and DXB and not in mRPMI 1640 (p<0.001). No statistically significant differences were detected between the MIC values registered after 48h and 72h incubation. ITZ displayed lower MIC values than KTZ and FLZ regardless of the media employed. A large number of FLZ-resistant Malassezia strains (86.6%) was observed using DXB. A MIC>64mg/L was observed only when the FLZ-resistant M. pachydermatis isolate was tested in SDB. Based on the results obtained herein, culture in SDB, stock inoculum suspensions of 1-5×10(6)CFU/ml, and an incubation time of 48h are proposed as optimal conditions for the evaluation of the in vitro antifungal susceptibility of M. pachydermatis using a modified CLSI BMD protocol.
Until recently, Cryptococcus gattii infections occurred mainly in tropical and subtropical climate zones. However, during the past decade, C. gattii infections in humans and animals in Europe have increased. To determine whether the infections in Europe were acquired from an autochthonous source or associated with travel, we used multilocus sequence typing to compare 100 isolates from Europe (57 from 40 human patients, 22 from the environment, and 21 from animals) with 191 isolates from around the world. Of the 57 human patient isolates, 47 (83%) were obtained since 1995. Among the 40 patients, 24 (60%) probably acquired the C. gattii infection outside Europe; the remaining 16 (40%) probably acquired the infection within Europe. Human patient isolates from Mediterranean Europe clustered into a distinct genotype with animal and environmental isolates. These results indicate that reactivation of dormant C. gattii infections can occur many years after the infectious agent was acquired elsewhere.
This study aims to determine the minimal inhibitory concentration (MIC) distribution and the epidemiological cut-off values (ECVs) of Malassezia pachydermatis and Malassezia furfur isolates for fluconazole (FLZ), itraconazole (ITZ), posaconazole (POS), and voriconazole (VOR). A total of 62 M. pachydermatis strains from dogs with dermatitis and 78 M. furfur strains from humans with bloodstream infections (BSI) were tested by a modified broth microdilution Clinical and Laboratory Standards Institute (CLSI) method. ITZ and POS displayed lower MICs than VOR and FLZ, regardless of the Malassezia species. The MIC data for azoles of M. pachydermatis were four two-fold dilutions lower than those of M. furfur. Based on the ECVs, about 94% of Malassezia strains might be categorized within susceptible population for all azoles, except for FLZ, and azole cross-resistance was detected in association with FLZ in M. pachydermatis but not in M. furfur. The study proposes, for the first time, tentative azole ECVs for M. pachydermatis and M. furfur for monitoring the emergence of isolates with decreased susceptibilities and shows that the azole MIC distribution varied according to the Malassezia species tested, thus suggesting the usefulness of determining the susceptibility profile for effective treatment of each species.
Despite being considered an emerging yeast related to immunocompromised individuals, severe infections by Malassezia furfur have not been evaluated. During a one-year survey on yeasts fungemia, 290 neonatal and 17 pediatric patients with intravascular catheters, lipid parenteral nutrition, prolonged ward stay, and surgery were enrolled. In addition, the origin of the infection was investigated by swabbing hand skin of patients, parents, and healthcare workers and medical devices. All biological specimens and swabs were cultured on Sabouraud dextrose agar and Dixon agar. The yeasts identification was based on morphological and biochemical features and by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and confirmed by sequencing the internal transcribed spacer of nuclear ribosomal DNA. A higher prevalence of M. furfur (2.1%) over Candida spp. (1.4%) caused bloodstream infections (BSIs). Twelve fungemia episodes were recorded: 2 by M. furfur in a pediatric ward and 10 in a neonatal intensive care unit (6 caused by M. furfur and 4 by Candida spp.). M. furfur was also isolated from the skin of all patients with BSIs, from the hand skin of a parent, and from an incubator surface and sheet. Patients with Candida spp. and M. furfur BSIs were successfully treated with intravenous liposomal Amphotericin B. These findings highlight the need for a more accurate etiological diagnosis in high-risk patients by adding lipid-supplemented culture media for Malassezia in the current mycological routine as the clinical features, patient management, and outcomes in both Candida and Malassezia fungemia do not differ.
The occurrence of Malassezia spp. bloodstream infections (BSIs) in neonatal intensive care unit was evaluated by using pediatric Isolator, BacT/Alert systems and central venous catheter (CVC) culture. The efficacy of BacT/Alert system in detecting Malassezia was assessed by conventional procedures, culturing 1 ml of bottle content before incubation and by studying the survival of Malassezia spp. strains in BacT/Alert bottles. Of the 492 neonates enrolled, blood was collected by pediatric Isolator (290 patients; group I) or by BacT/Alert bottles (202 patients; group II). The survival of Malassezia furfur and Malassezia pachydermatis in BacT/Alert bottles was evaluated by culturing the inoculum suspension (from 106 to 10 colony-forming units, cfu/ml) and assessing the cfu/ml for 15 days. In total, 15 Malassezia BSIs were detected, of which six (2.1%) from both blood and CVC culture in Dixon agar (DixA) in patients belong to group I (blood collected by paediatric Isolator tube) and nine (4.4%) only from CVC culture in DixA in patients of group II (blood collected by BacT/Alert bottle). Only one patient (0.5%) from group II scored positive for M. furfur also by culturing in DixA 1 ml blood content of BacT/Alert bottle before incubation in BacT/Alert system.M. furfur population size in BacT/Alert bottles decreased during the incubation time, whereas that of M. pachydermatis increased. The BacT/Alert system detected M. pachydermatis even at very low concentration (i.e., 10 cfu/ml) but not any positive blood culture for M. furfur. For a correct diagnosis of Malassezia furfur BSI, the blood should be culture in lipid-enriched fungal medium, and the BacT/Alert system implemented by adding lipid substrates to increase the method sensibility. Finally, CVC cultures on lipid-supplemented media may be proposed as a routine procedure to diagnose the Malassezia fungemia.
BACKGROUND: Candida bloodstream infections (BSI) represent an important problem in Intensive Care Units (ICUs). The epidemiology of candidemia is changing with an increase in the proportion of Candida (C.) non-albicans. OBJECTIVES: An Italian 2-year observational survey on ICU was conducted to evaluate the species distribution and possible differences between BSI caused by C. albicans and C. non-albicans. For comparative purposes, we performed a European literature-based review to evaluate distribution and frequency of Candida spp. causing ICU candidemia, during the period 2000-2013. MATERIALS AND METHODS: This laboratorybased survey involved 15 microbiology centers (GISIA-3 study). All candidemia episodes in adult patients were considered. Data were prospectively collected from 2007 to 2008. PubMed was searched for peer-reviewed articles. RESULTS: In total, 462 candidemia episodes were collected. C. albicans accounted for 49.4% of the isolates, followed by C. parapsilosis (26.2%) and C. glabrata (10.4%). Mortality was higher in patients with C. non-albicans than C. albicans (47.3% vs. 32.4 %, p > 0.05). Among risk factors, parenteral nutrition was more common (p = 0.02) in non-albicans candidemia, while surgery was more frequent (p = 0.02) in C. albicans candidemia. Twenty-four relevant articles were identified. C. albicans was the predominant species in almost all studies (range 37.9% -76.3%). C. glabrata was commonly isolated in the German-speaking countries, France, UK and North Europe; C. parapsilosis in Turkey, Greece and Spain. CONCLUSIONS: Although C. non-albicans BSI is increasing, our study shows that C. albicans is still the predominant species in ICU candidemia. There are differences in the epidemiology of Candida BSI among European countries, with a prevalence of C. glabrata and C. parapsilosis in Northern and Southern countries, respectively.
In the present work, we studied the distribution of Candida parapsilosis complex species and the antifungal susceptibility of clinical isolates collected during an Italian surveillance study of yeast invasive fungal infections (IFIs) in intensive care units (ICUs). Minimum inhibitory concentrations (MICs) were determined using the Clinical and Laboratory Standards Institute (CLSI) reference broth microdilution method. BanI digestion patterns of the secondary alcohol dehydrogenase polymerase chain reaction (PCR) products were used to identify C. parapsilosis sensu stricto, C. orthopsilosis, and C. metapsilosis. A total of 138 C. parapsilosis isolates were stored (January 2007-December 2008). The overall frequency of C. parapsilosis complex in IFIs was 22%. Of the 138 tested isolates, 95% were C. parapsilosis sensu stricto, 3.6% were C. orthopsilosis, and 1.4% were C. metapsilosis. The MIC(50) values (expressed as μg/ml) for anidulafungin, caspofungin, and micafungin for C. parapsilosis complex were 2, 1, and 2, respectively, and the MIC(90) values were 4, 2, and 4, respectively. The MIC(50) and MIC(90) values for itraconazole and posaconazole were 0.12 and 0.25, respectively, and for fluconazole, they were 1 and 4, respectively. This study, the most comprehensive study conducted to date to evaluate the frequency and antifungal susceptibility profiles of C. parapsilosis complex isolates from critically ill patients in Italy, highlights the low prevalence of C. orthopsilosis and C. metapsilosis in IFIs.
Over the past 20 years,Thelazia callipaeda(the oriental eyeworm) has become endemic in Europe, infecting domestic and wild carnivores and humans. The vector of this nematode, the fruit flyPhortica variegata, has recently been discovered in the United States, and its vector competence is demonstrated forT. callipaedain this article, therefore representing a potential new threat for infection of carnivores and humans in the United States.
Cryptococcus gattii has becoming more prevalent in temperate climate zones, during the past decades. We describe a C. gattii serotype B infection in an immunocompetent Italian patient with sclerosing cholangitis. The patient traveled once to Eastern Canada and otherwise no other countries than Italy were visited. Molecular analysis revealed that the C. gattii isolate belong to genotype AFLP4/VGI and has mating-type α which is the most common genotype in the Mediterranean environment. The C. gattii strain was found to be closely related, but not identical, to other C. gattii strains from the Mediterranean area
Cryptococcosis is a fungal disease acquired from the environment, for which animals may serve as sentinels for human exposure. The occurrence of Cryptococcus spp. in the respiratory tract of 125 squirrels, Callosciurus finlaysonii, trapped in Southern Italy, was assessed. Upon examination of nasal swabs and lung tissue from each individual, a total of 13 (10.4%) animals scored positive for yeasts, 7 for Cryptococcus neoformans (C.n.) (5.6%) and 6 for other yeasts (4.8%). C.n. was isolated from the nostrils and lungs, with a high population size in nostrils. Two C.n. molecular types, VNI and VNIV, were identified, with C.n. var. grubii VNI the most prevalent. Phylogenetic analyses of ITS+ and URA5 sequences revealed that C.n. isolates were genetically similar to isolates from a range of geographical areas and hosts. Results suggest that C.n. can colonize or infect the respiratory tract of C. finlaysonii. The high occurrence and level of colonization of nasal cavities might be an indicator of environmental exposure to high levels of airborne microorganism. The close phylogenetic relationship of C.n. strains from squirrels with those from human and other animal hosts suggests a potential role for these animals as “sentinels” for human exposure.
Phlebotomine sand flies (Diptera, Psychodidae) are vectors of Leishmania spp., among which Leishmania infantum is recognized as the main agent of human and canine leishmaniosis (CanL) in the Mediterranean area. In this study, females of Phlebotomus spp. (P. perniciosus, P. neglectus and P. papatasi) and Sergentomyia minuta were collected in a dog shelter of southern Italy, where CanL is endemic, and examined for Leishmania DNA. In total, 32 out of 56 of Phlebotomus spp. insects (57.1%) were found positive for L. infantum DNA by quantitative PCR (qPCR), with a mean parasite load of 1.9 x 103 promastigotes/ml among 23 positive P. perniciosus and 2.1 x 103 promastigotes/ml among five positive P. neglectus. Four P. papatasi, a species known to be refractory to L. infantum development, were also found positive. Among 216 S. minuta specimens examined, 25 (11.6%) scored positive for Leishmania tarentolae by conventional nested PCR; two (16.7%) of them were also positive for lizard blood, which is in agreement with the feeding preference of this phlebotomine species. Nine S. minuta (4.2%) were positive for L. infantum by qPCR, with a mean parasite load of 1.62 × 102 promastigotes/ml. The detection of L. infantum DNA in S. minuta may suggest that this species could acquire the protozoan, occasionally feeding on infected dogs. Further investigations need to clarify the potential role that S. minuta may have in the transmission of L. infantum to receptive mammal hosts.
Infections caused by Malassezia yeasts are most likely underdiagnosed, because fatty acid supplementation is needed for growth. Rapid identification of Malassezia species is essential for appropriate treatment of Malassezia-related skin infections, fungaemia and nosocomial outbreaks in neonates, children and adults and can be life-saving for those patients. Ma-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has been reported to be a rapid and reliable diagnostic tool to identify clinically important yeasts, but so far no data have been reported on identification of Malassezia isolates with this technique. OBJECTIVES: To create an extensive database of main mass spectra (MSPs) that will allow quick identification of Malassezia species by MALDI-TOF MS. METHODS: An in-house library of 113 MSPs was created from 48 reference strains from the CBS-KNAW yeast collection. The in-house library was challenged with two test sets of Malassezia strains, namely 165 reference strains from the CBS collection and 338 isolates collected in Greece, Italy, Sweden and Thailand. RESULTS: MALDI-TOF MS allowed correct identification of all 14 Malassezia spp. MALDI-TOF MS results were concordant with those of sequence analyses of the internal transcribed spacers (ITS1/ITS2) and the D1/D2 domains of the large subunit of the ribosomal DNA. CONCLUSIONS: Implementation of the MALDI-TOF MS system as a routine identification tool will contribute to correct identification of Malassezia yeasts with minimal effort and in a short turnaround time, which is especially important for the rapid identification of Malassezia in skin diseases and nosocomial outbreaks.
Data on the occurrence and epidemiology of Aspergillus spp. in laying hens farms are scant. With the aims of determining levels of airborne contamination in laying hen farms and evaluating the potential risk of infection for workers and animals, 57 air samples from 19 sheds (Group I), 69 from faeces (Group II), 19 from poultry feedstuffs (Group III) and 60 from three anatomical sites (i.e. nostrils, pharynx, ears) of 20 farm workers (Group IV) were cultured. The Aspergillus spp. prevalence in samples ranged from 31.6% (Group III) to 55.5% (Group IV), whereas the highest conidia concentration was retrieved in Group II (1.2 × 10(4) c.f.u. g(-1)) and in Group III (1.9 × 10(3) c.f.u. g(-1)). The mean concentration of airborne Aspergillus spp. conidia was 70 c.f.u. m(-3) with Aspergillus fumigatus (27.3%) being the most frequently detected species, followed by Aspergillus flavus (6.3%). These Aspergillus spp. were also isolated from human nostrils (40%) and ears (35%) (P<0.05) (Group IV). No clinical aspergillosis was diagnosed in hens. The results demonstrate a relationship between the environmental contamination in hen farms and presence of Aspergillus spp. on animals and humans. Even if the concentration of airborne Aspergillus spp. conidia (i.e. 70 c.f.u. m(-3)) herein detected does not trigger clinical disease in hens, it causes human colonization. Correct management of hen farms is necessary to control environmental contamination by Aspergillus spp., and could lead to a significant reduction of animal and human colonization.
Legionella spp. is considered an emerging microorganism involved in aquatic environments contamination and cause of Legionnaires' disease. The aims of the study are to evaluate the level of contamination of Legionella spp. in the water system of the largest Hospital of Apulia region during a 4-year surveillance and to establish, by molecular method, the presence of a predominant genotype of L. pn. sg 1. The results showed that Legionella spp. was present in 36% of water samples with Legionella pneumophila serogroup 1 (L. pn. sg 1) the most prevalent species and serogroup and the wards most contaminated are the high risk units. In addition, despite four main clones of L. pn. sg 1 were identified, a predominant genotype existed. In conclusion the study demonstrates the necessity for periodic evaluation on hospitals water system to assess the potential contamination of Legionella spp., performing decontamination in the presence of bacterial contamination, even low, in particular in high risk wards. Moreover, the switching of the disinfection methods may be suggested in order to prevent resistance phenomenon by some L. pn. sg 1 clones.
Purpose: The aims of this study are to evaluate the epidemiology of invasive fungal infections (IFIs) in patients admitted to an intensive care unit (ICU) in Southern Italy and the in vitro antifungal susceptibility of isolates. Methods: A surveillance program was implemented in 18 ICUs. IFI cases were recorded using a standardized form. Results: A total of 105 episodes of IFIs occurred in 5,561 patients during the 18-month study. The main infections were caused by yeasts, more than filamentous fungi (overall incidence of 16.5 cases per 1,000 admissions and 2.3 cases per 1,000 admissions, respectively). The overall crude mortality rate was high (42.8 %), particularly for mold infections (61.5 %). All yeast infections were Candida bloodstream infections. Over half (59.8 %) were caused by Candida non-albicans, with C. parapsilosis being the most common (61.8 %). In the multivariate model, trauma admission diagnosis, prolonged stay in the ICU, and parenteral nutrition were independently associated with candidemia due to C. parapsilosis [odds ratio (OR) 3.5, (1.8-5.2); OR 3.5, (1.02-3.5); OR 3.6, (1.28-6.99), respectively]. Among mold infections, 12 patients suffered from invasive pulmonary aspergillosis, with Aspergillus fumigatus as the predominant pathogen (41.7 %). One case of brain scedosporiosis was identified. Overall, azoles and echinocandins resistance was uncommon. Conclusions: Candida non-albicans species are the most frequent cause of candidemia in ICU patients. Mold infections are associated with a high mortality rate. This study confirms the importance of the epidemiological surveillance on IFIs in the ICU setting for documenting species distribution and antimicrobial susceptibility patterns to guide therapeutic choices.
Although guidelines for the treatment of Malassezia furfur fungemia are not yet defined, clinical data suggest that amphotericin B (AmB) is effective for treating systemic infections. In the absence of clinical breakpoints for Malassezia yeasts, epidemiological cut-off values (ECVs) are useful to discriminate between isolates with and without drug resistance. This study aimed to compare the distribution of minimal inhibitory concentration (MIC) and the ECVs for AmB of both deoxycholate (d-AmB) and liposomal (l-AmB) formulations of M. furfur isolates. The 84 M. furfur strains analyzed, which included 56 from blood, sterile sites and catheters, and 28 from skin, were isolated from patients with bloodstream infections. MICs were determined by the modified broth microdilution method of the Clinical and Laboratory Standards Institute (CLSI). The l-AmB MIC and the ECVs were two-fold lower than those of d-AmB and a lower l-AmB mean MIC value was found for blood isolates than from skin. The ECVs for l-AmB and d-AmB were 8 mg/l and 32 mg/l, respectively. Three strains (3.6%) showed l-AmB MIC higher than ECV (MIC > 8mg/l) of which two were isolated from the catheter tip of patients treated with micafugin, l-Amb and fluconazole, and one from skin. The results showed that the l-AmB might be employed for assessing the in vitro antifungal susceptibility of M. furfur by a modified CLSI protocol and that ECVs might be useful for detecting the emergence of resistance.
Fungaemia caused by Malassezia spp. in hospitalized patients requires prompt and appropriate therapy, but standard methods for the definition of the in vitro antifungal susceptibility have not been established yet. In this study, the in vitro susceptibility of Malassezia furfur from bloodstream infections (BSIs) to amphotericin B (AMB), fluconazole (FLC), itraconazole (ITC), posaconazole (POS) and voriconazole (VRC) was assessed using the broth microdilution (BMD) method of the Clinical and Laboratory Standards Institute (CLSI) with different media such as modified Sabouraud dextrose broth (SDB), RPMI and Christensen's urea broth (CUB). Optimal broth media that allow sufficient growth of M. furfur, and produce reliable and reproducible MICs using the CLSI BMD protocol were assessed. Thirty-six M. furfur isolates collected from BSIs of patients before and during AMB therapy, and receiving FLC prophylaxis, were tested. A good growth of M. furfur was observed in RPMI, CUB and SDB at 32 °C for 48 and 72 h. No statistically significant differences were detected between the MIC values registered after 48 and 72 h incubation. ITC, POS and VRC displayed lower MICs than FLC and AMB. These last two antifungal drugs showed higher and lower MICs, respectively, when the isolates were tested in SDB. SDB is the only medium in which it is possible to detect isolates with high FLC MICs in patients receiving FLC prophylaxis. A large number of isolates showed high AMB MIC values regardless of the media used. In conclusion, SDB might be suitable to determine triazole susceptibility. However, the media, the drug formulation or the breakpoints herein applied might not be useful for assessing the AMB susceptibility of M. furfur from BSIs.
Canine Malassezia dermatitis is frequently treated with systemic ketoconazole (KTZ) and itraconazole (ITZ). However, no information is available on the antifungal susceptibility to azoles and allilamine of Malassezia pachydermatis isolates from dogs with or without skin lesions. The present study was designed to evaluate the in vitro antifungal susceptibility of M. pachydermatis strains from dogs with or without skin lesions to KTZ, ITZ, miconazole (MICO), fluconazole (FLZ), posaconazole (POS), voriconazole (VOR) and terbinafine (TER) using the Clinical and Laboratory Standards Institute reference Broth Microdilution Method (CLSI M27-A2). The association between the susceptibility to antifungal compounds and the origin of M. pachydermatis, from skin with or without lesions has been also assessed. A total of 62 M. pachydermatis strains from healthy dogs (i.e., Group A=30) or with skin lesions (i.e., Group B=32) were tested. ITZ, KTZ and POS showed the highest activity against M. pachydermatis strains, whereas MICO TER and FLZ the lowest. A higher number of Malassezia resistant strains were registered among isolates from Group B than those from Group A. This study indicates that M. pachydermatis strains were susceptible to ITZ, KTZ, and POS. However, dogs with lesions may harbour strains with low susceptibility to antifungal agents and displaying cross-resistance phenomena to azole. The antifungal therapy in Malassezia infections requires careful appraisal of choice of drugs especially in cases of unresponsiveness to antifungal treatment or recurrent infections.
Dermatitis caused by Malassezia spp., one of most common skin disease in dogs, requires prolonged therapy and/or high doses of antifungal agents. In the present study, the antifungal susceptibility of M. pachydermatis to ketoconazole (KTZ), fluconazole (FLZ), itraconazole (ITZ), posaconazole (POS) and voriconazole (VOR) was evaluated in vitro using both CLSI reference broth microdilution (CLSI BMD) and E-test. A total of 62 M. pachydermatis strains from dogs with and without skin lesions were tested. M. pachydermatis strains were susceptible to ITZ, KTZ and POS using both test methods, with the highest MIC found in tests of FLZ. Essential agreement between the two methods ranged from 87.1% (VOR) to 91.9% (ITZ), and categorical agreement from 74.2% (FLZ) to 96.8% (ITZ). Minor error discrepancies were observed between the two methods, with major discrepancies observed for KTZ. A higher MIC(50) value for FLZ was noted with M. pachydermatis genotype B. The MICs(50) of M. pachydermatis genotype B for KTZ, VOR and POS were higher in isolates from dogs with skin lesions than those in isolates from animals without skin lesions. The results suggest a link between genotypes of M. pachydermatis and in vitro drug susceptibility. The categorical agreement for both E-test and CLSI BMD methods found in this investigation confirms the E-test as a reliable diagnostic method for routine use in clinical mycology laboratories.
Introduction. During the past years invasive fungal infections (IFIs) have become an increasingly important problem in infants hospitalized in the Neonatal Intensive Care Unit (NICU). Candida species is the third most-common agent of late-onset infections in critically ill neonates, with an estimated incidence of 2.6-10% in very low birth weight and 5.5-20% in extremely low birth weight infants. The aim of this observational study is to evaluate the epidemiology of IFIs among infants admitted to NICUs of one Italian region by a multicenter surveillance (Aurora Project). Methods. The IFIs surveillance was carried out prospectively in Apulia (Southern Italy) between February 2007 and August 2008. This report focuses on the results from 6 enrolled NICUs. Results. Twenty-one neonates developed IFIs: the overall incidence was 1.3% and crude mortality was 23.8%. Infants weighing ≤ 1500 g (4.3%) showed a significantly higher incidence than those ≥ 2500 g (0.2%). C.parapsilosis (61.9%) was the most frequent isolated species. The main potential risk factors were having a central venous catheter placed, length of stay in NICU > 7 days and total parenteral nutrition for > 5 days. The (1,3)-β-D glucan (BDG), mannan antigens and anti-Candida antibodies' evaluation was performed in 7 neonates. All neonates were positive to the BDG; the mannan antigen result was positive in 5 newborns, the anti-mannan antibodies were always negative. All isolates were amphotericin B and fluconazole-susceptible. Discussion. This first prospective study on neonatal fungal infection in one Italian region gives evidence of a preponderance of non-albicans Candida spp and indicates potential utility of BDG as an adjunct diagnostic test.
Background: Following the publication of the Italian Guidelines for the control and prevention of legionellosis an environmental and clinical surveillance has been carried out in Southeastern Italy. The aim of the study is to identify the risk factors for the disease, so allowing better programming of the necessary prevention measures. Methods: During the period January 2000 - December 2009 the environmental surveillance was carried out by water sampling of 129 health care facilities (73 public and 56 private hospitals) and 533 buildings within the community (63 private apartments, 305 hotels, 19 offices, 4 churches, 116 gyms, 3 swimming pools and 23 schools). Water sampling and microbiological analysis were carried out following the Italian Guidelines. From January 2005, all facilities were subject to risk analysis through the use of a standardized report; the results were classified as good (G), medium (M) and bad (B). As well, all the clinical surveillance forms for legionellosis, which must be compiled by physicians and sent to the Regional Centre for Epidemiology (OER), were analyzed. Results: Legionella spp. was found in 102 (79.1%) health care facilities and in 238 (44.7%) community buildings. The percentages for the contamination levels < 1,000, 1,000-10,000, > 10,000 cfu/L were respectively 33.1%, 53.4% and 13.5% for samples from health care facilities and 33.5%, 43.3% and 23.2% for samples from the community. Both in hospital and community environments, Legionella pneumophila serogroup (L. pn sg) 2-14 was the most frequently isolate (respectively 54.8% and 40.8% of positive samples), followed by L. pn sg 1 (respectively 31.3% and 33%). The study showed a significant association between M or B score at the risk analysis and Legionella spp. positive microbiological test results (p < 0.001). From clinical surveillance, during the period January 2001 - August 2009, 97 cases of legionellosis were reported to the OER: 88 of community origin and 9 nosocomial. The most frequent symptoms were: fever (93.8%), cough (70.1%), dyspnea (58.8%), shivering (56.7%). Radiological evidence of pneumonia was reported in 68%. The laboratory diagnostic methods used were: urinary antigen (54.3%), single antibody titer (19.8%), only seroconversion (11.1%), other diagnostic methods (14.8%). Conclusions: Our experience suggests that risk analysis and environmental microbiological surveillance should be carried out more frequently to control the environmental spread of Legionella spp. Furthermore, the laboratory diagnosis of legionellosis cannot be excluded only on the basis of a single negative test: some patients were positive to only one of the diagnostic tests.
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) offers an effective alternative to phenotypic and molecular methods for the rapid identification of microorganisms. Our aim in this study was to create an in-house library for a set of strains of nine uncommonly reported human and animal cryptococcal species, including Cryptococcus adeliensis, C. albidosimilis, C. albidus, C. aureus, C. carnescens, C. laurentii, C. magnus, C. victoriae and C. uniguttulatus, and to use this library to make timely and correct identifications using MALDI-TOF MS for use in routine laboratory diagnostics. Protein extracts obtained via the formic acid extraction method of 62 veterinary non-C. neoformans-C. gattii cryptococcal isolates were studied. The obtained mass spectra correctly grouped all 62 studied isolates according to species identification previously obtained by internal transcribe spacer sequence analysis. The in-house database was than exported and successfully uploaded to the Microflex LT (Maldi Biotyper; Bruker Daltonics) instrument at a different diagnostic laboratory in Italy. Scores >2.7 obtained from isolates reanalyzed in the latter laboratory supported the high reproducibility of the method. The possibility of creating and transferring an in-house library adds to the usefulness MALDI-TOF MS an important tool for the rapid and inexpensive identification of pathogenic and saprophytic fungi as required for differential diagnosis of human and animal mycoses
Dermatophytes are fungi that invade and propagate in the keratinized skin of mammals, including humans, often causing contagious infections. The species of medical concern belong to the genera Microsporum, Trichophyton, Epidermophyton (in their anamorphic state) and Arthroderma (in their telomorphic state), which were traditionally identified based on their morphology and biochemical characters. Nonetheless, limitations linked to the differentiation of closely related agents at species and strains level have been recently overcome by molecular studies. Indeed, an accurate identification of dermatophytes is pivotal for the establishment of effective control and prevention programs as well as for determining the most appropriate and effective antifungal therapies to be applied. This article reviews the DNA techniques and the molecular markers used to identify and to characterize dermatophyte species, as well as aspects of their phylogeny and evolution. The applications of typing molecular strain to both basic and applied research (e.g., taxonomy, ecology, typing of infection, antifungal susceptibility) have also been discussed.
Background Rhipicephalus sanguineus sensu lato ticks are widespread worldwide due to their adaptability to survive under different environmental conditions. They may act as vectors of a wide range of pathogens to humans and animals and their control is based on the use of chemical products on dogs and in the environment. Alternative control strategies, such as the use of entomopathogenic fungi as bio-control agents have also been investigated. The ability of native strains of Beauveria bassiana sensu lato in causing mortality in different tick species (e.g., Amblyomma cajennense and Rhipicephalus microplus) has been demonstrated. However, limited studies have assessed the use of B. bassiana for the control of R. sanguineus s.l. and none of them have employed native strains of this fungus. Here we investigated the pathogenicity of a native strain of B. bassiana (CD1123) against all developmental stages of R. sanguineus s.l.. Methods Batches of eggs, larvae, nymphs and adult ticks were immersed in a suspension of 107 conidia/ml of B. bassiana s.l., isolated from a R. sanguineus s.l. engorged female. All treatment and control groups were observed for 20 days, and the biological parameters (i.e., mortality, hatching, moulting percentage, pre-oviposition period, oviposition period and rate, eggs production efficiency, reproductive efficiency and fitness indexes) were assessed. Results The effect of the B. bassiana strain tested herein on eggs, larvae, nymphs and adults showed a significantly higher mortality than those of the control groups (p < 0.05) at 5 days post-infection. No infected eggs hatched and no infected larvae moulted. Only 15% of infected nymphs moulted into adults. All biological parameters of treated groups differed significantly (p < 0.001) from those of control groups. Conclusions This study demonstrates that a suspension containing 107 conidia/ml of a native B. bassiana strain is highly virulent towards all life-cycle developmental stages of R. sanguineus s.l. and may be of potential interest as a biological control agent against these ticks.
Strongyloidiosis by Strongyloides stercoralis is a disease of increasing interest in human and animal medicine. The scientific knowledge on canine strongyloidiosis is hindered by the poor diagnostics available. To assess the most sensitive and specific diagnostic method, feces and blood from 100 shelter dogs were screened for S. stercoralis by coprological, molecular and serological tests. Thirty-six dogs (36%) scored positive to S. stercoralis by coprology (22.3% to Baermann) and/or 30% to real time-polymerase chain reaction (rt-PCR). According to two composite reference standards (CRS) based on all coprological methods and rt-PCR (first CRS) or in combination with serology (second CRS), the most sensitive test was IFAT (93.8%; CI 82.8-98.7), followed by rt-PCR (80.6%; 95% CI 64-91.8) and Baermann (60.6%; 95% CI 42.1-77.1). The inconsistent shedding of L1 during the 4-week follow-up in infected dogs suggests the importance of multiple faecal collections for a reliable diagnosis. A combination of serological and coprological tests is recommended for the surveillance and diagnosis of S. stercoralis infection in dogs.
ATP-binding cassette (ABC) transporters have been shown to be involved in pesticide detoxification in arthropod vectors and are thought to contribute to the development of drug resistance. Little is currently known about the role they play in ticks, which are among the more important vectors of human and animal pathogens. Here, the role of ABC transporters in the transport of fipronil and ivermectin acaricides in the tick Rhipicephalus sanguineus (Ixodida: Ixodidae) was investigated. Larvae were treated with acaricide alone and acaricide in combination with a sub-lethal dose of the ABC transporter inhibitor cyclosporine A. The LC50 doses and 95% confidence intervals (CIs) estimated by mortality data using probit analysis were 67.930p.p.m. (95% CI 53.780-90.861) for fipronil and 3741p.p.m. (95% CI 2857-4647) for ivermectin. The pre-exposure of larvae to a sub-lethal dose of cyclosporine A reduced the LC50 dose of fipronil to 4.808p.p.m. (95% CI 0.715-9.527) and that of ivermectin to 167p.p.m. (95% CI 15-449), which increased toxicity by about 14- and 22-fold, respectively. The comparison of mortality data for each separate acaricide concentration showed the synergic effect of cyclosporine A to be reduced at higher concentrations of acaricide. These results show for the first time a strong association between ABC transporters and acaricide detoxification in R.sanguineus s.l.
OBJECTIVE: This study aim was to determine the prevalence of microorganisms in the respiratory tract of patients with cystic fibrosis (CF) admitted to the CF Reference Centre in Southern Italy between 2002-2010. METHODS: Microbiology assessment of samples (sputum and tracheal aspirates) collected from patients with pulmonary exacerbation admitted to hospital was carried out. All patients were registered in a database and clinical and microbiological data were retrospectively analysed. RESULTS: Overall, 188 patients were included and a total of 1217 samples were analysed. The most common microorganisms were Staphylococcus aureus (78.7% of the patients) and Pseudomonas aeruginosa (58%), followed by Candida albicans (19.1%), Haemophilus influenzae (13.3%) and Aspergillus fumigatus (9.6%). CONCLUSION: Compared to similar studies performed in other European countries, our microbiological data, especially the low occurrence of filamentous fungi, suggest a specific local epidemiology, probably related to some uncommon CFTR mutations, which are specific to Southern Italy.
Objective. The present report aims to molecularly characterize seven clinical L. pneumophila (L. pn.) sg 1 isolated from nosocomial acquired infections in Apulia region, using the European Working Group on Legionella Infections (EWGLI), sequence-based typing (SBT) and amplified fragment length polymorphism (AFLP) protocols and to compare the identified sequence types (STs) with those available in the EWGLI database. Methods. In the period, January 2000-December 2012, 151 cases (136 of community and 15 of nosocomial origin) of Legionnaires' disease were notified to the Regional Center for Epidemiology. With regard to nosocomial cases, 8 were confirmed by the isolation of Legionella spp. from respiratory secretions. These clinical isolates were characterized by amplified fragment length polymorphism (AFLP) and sequence-based typing (SBT), using the EWGLI standardized protocol. Results. The clinical isolates belong to ST42, ST23 and ST1. The AFLP confirms the SBT results. Comparing the STs herein detected with those already in the EWGLI SBT database, the 3 STs are frequent in other European countries. Conclusions. The molecular analysis demonstrates that the 3 STs are the most frequent in Italy and in Europe, supporting the hypothesis that some specific L. pn. sg 1 clones have gained widespread dissemination probably due to a common ecological niche. Further researches are required to investigate the potential changing incidence of STs and the fitness of emerging strains or clonal groups in environmental strains
Nelle strutture termali diversi fattori, ad es. la temperatura delle acque impiegate, possono favorire la moltiplicazione di microrganismi come Legionella spp. La tipologia di utenza che frequenta queste strutture è spesso rappresentata anche da soggetti a rischio infettivo che si sottopongono a terapia inalatoria e a trattamenti in vasche idromassaggio. Di conseguenza, in mancanza di un'attenta gestione degli impianti, questi ambienti possono rappresentare una possibile sorgente di infezione da Legionella spp. Scopo del presente studio è verificare lo stato dell'arte della normativa italiana e pugliese che regola il controllo della contaminazione da Legionella spp. nelle strutture termali.
Domestic and wild birds may act as carriers of human pathogenic fungi, although the role of laying hens in spreading yeasts has never been investigated. We evaluated the presence of yeasts in the cloaca (Group I, n = 364), feces (Group II, n = 96), and eggs (Group III, n = 270) of laying hens. The occurrence and the population size of yeasts on the eggshell, as well as in the yolks and albumens, were assessed at the oviposition time and during storage of eggs at 22 ± 1°C and 4 ± 1°C. A statistically higher prevalence and population size of yeasts were recorded in Group I (49.7% and 1.3 × 104 cfu/ml) and II (63.8% and 2.8 × 105 cfu/ml) than in Group III (20.7% and 19.9 cfu/ml). Candida catenulata and Candida albicans were the most frequent species isolated. Candida famata and Trichosporon asteroides were isolated only from the eggshells, whereas Candida catenulata was also isolated from yolks and albumens. During storage, the yeast population size on the shell decreased (from 37.5 to 8.5 cfu/ml) in eggs at 22 ± 1°C and increased (from 4.6 to 35.3 cfu/ml) at 4 ± 1°C. The laying hens harbor potentially pathogenic yeasts in their gastrointestinal tract and are prone to disseminating them in the environment through the feces and eggs. Eggshell contamination might occur during the passage through the cloaca or following deposition whereas yolk and albumen contamination might depend on yeast density on eggshell.
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