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.

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.

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.

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 ofCryptococcus neoformansand 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.