Seasonal variation in canine anti-Leishmania infantum antibody titres.

Quantitative anti-Leishmania antibody titres are critical in the management of dogs with leishmaniosis, from diagnosis to treatment and follow-up, and there is a paucity of data relating changes in antibody titres to sand fly vector seasonality. This study aimed to evaluate seasonal variations in anti-Leishmania infantum antibody titres in dogs from a hyperendemic area for canine leishmaniosis (CanL). Leishmania infantum-seropositive and clinically healthy dogs (n=65) were sampled in June 2019 (sand fly season) and again in February-March 2020 (non-transmission season) to monitor clinical status and serological titres. There was a reduction in anti-L. infantum antibody titres during the non-transmission season in most dogs (n=36; 55.4%), and 44% of those dogs (n=16/36) became seronegative (i.e. below the cut-off value of 1:80). Given the relevance of serology to epidemiological, preventive and clinical studies related to CanL, seasonal variations in antibody titres are important in areas where phlebotomine vectors have seasonal patterns of activity. Sand fly seasonal period must be considered in the interpretation of annual anti-L. infantum antibody screening test results in asymptomatic dogs, to make clinical decisions about staging, treatment and prevention.

Potential role of ATP-binding cassette transporters against acaricides in the brown dog tick Rhipicephalus sanguineus sensu lato.

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 67.930 p.p.m. (95% CI 53.780-90.861) for fipronil and 3741 p.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 4.808 p.p.m. (95% CI 0.715-9.527) and that of ivermectin to 167 p.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.

Candidemia in intensive care unit: a nationwide prospective observational survey (GISIA-3 study) and review of the European literature from 2000 through 2013.

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 laboratory-based 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.

Efficient identification of Malassezia yeasts by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS).

BACKGROUND: 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.

Environmental surveillance and molecular investigation of Legionella spp. in Apulia, in the years 2008-2011.

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.

Epidemiology of invasive fungal infections in the intensive care unit: results of a multicenter Italian survey (AURORA Project).

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.

An innovative, easily fabricated, silver nanoparticle-based titanium implant coating: development and analytical characterization.

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 at the implant interface.

Sequence based typing of Legionella pneumophila sg 1 isolated in nosocomial acquired infections in Apulia, 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 is 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.

Antibiotic-modified hydrogel coatings on titanium dental implants.

Implant-associated infections represent an occasional but serious problem in dental and/or orthopaedic surgery. A possible solution to prevent the initial bacterial adhesion may be the coating of the implant surface with a thin layer of antibiotic-loaded biocompatible polymer. Hydrogels are one of the promising and versatile materials as antibiotic controlled release systems. In this work, antibiotic-modified poly(ethylene-glycol diacrylate) hydrogel coatings on titanium substrates were prepared by electrochemical polymerization and tested against methicillin resistant Staphylococcus aureus (ATCC 33591). Two different methods to load vancomycin and ceftriaxone were used. We show that the proposed titanium coatings displayed an interesting antibacterial activity, however, further studies on their effective cytotoxicity will furnish evidence of their real clinical efficacy.

Antifungal susceptibility testing of a 10-year collection of Candida spp. isolated from patients with candidemia.

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 expected, C. 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.

Characterization of Candida parapsilosis complex strains isolated from invasive fungal infections.

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.

Retrospective analysis of microorganisms isolated from cystic fibrosis patients in Southern Italy, 2002-2010.

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.

Invasive fungal infections in neonatal intensive care units of Southern Italy: a multicentre regional active surveillance (AURORA project).

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 < or = 1500 g (4.3%) showed a significantly higher incidence than those > or = 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)-beta-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.

Role of birds of prey as carriers and spreaders of Cryptococcus neoformans and other zoonotic yeasts.

In the last 20 years, cases of human cryptococcosis, have increased in immunocompromised patients. In several instances, the cases have been associated with the exposure of the patients to bird droppings. In order to investigate birds of prey as potential carriers and spreaders of Cryptococcus neoformans and other yeasts of importance in human infections, 182 swab samples were collected from the cloacae of several species of birds of prey (Group I) and 32 faecal samples from aviaries in which the birds were housed (Group II). Samples were also taken from digestive tract of 60 dead birds (Group III). A total of 454 samples were cultured from which 215 colonies of yeastlike fungi were recovered and identified. Cryptococcusneoformans var. grubii was isolated from three cloacae samples (4.8%) collected from Falco tinnunculus and from one sample (3.1%) obtained from Buteo buteo, as well as from samples collected at the aviaries in which these birds were kept. Overall, 18 samples (9.9%) from Group I, 13 (40.6%) from Group II, 12 crops (20%), three proventriculi (5%) and 12 cloacae (20%) from Group III yielded positive cultures for yeasts. The results indicate that birds of prey and in particular, F. tinnunculus and B. buteo, may act as carriers and spreaders of C. neoformans and other zoonotic yeasts.