Detection of Leishmania spp. in Chronic Dermatitis: Retrospective Study in Exposed Horse Populations.

Leishmania infantum is a protozoan causing human zoonotic visceral leishmaniasis (ZVL) and visceral-cutaneous canine leishmaniosis (CanL) in the Mediterranean Basin. L. infantum is able to infect a large number of wild and domestic species, including cats, dogs, and horses. Since the 1990s, clinical cases of equine leishmaniasis (EL), typically characterized by cutaneous forms, have been increasingly diagnosed worldwide. The aim of the present study was to evaluate the presence of clinical forms of EL in CanL-endemic areas in Italy, where exposure of equine populations was ascertained from recent serological surveys. For this purpose, formalin-fixed and paraffin-embedded skin biopsies of 47 horses presenting chronic dermatitis compatible with EL were retrospectively selected for the study and subjected to conventional and q-PCR. A singular positivity for L. infantum was found; BLAST analysis of sequence amplicons revealed a 99-100% homology with L. infantum sequences. The histological examination revealed a nodular lymphoplasmacytic and histiocytic infiltrate; immunohistochemistry showed rare macrophages containing numerous positive amastigotes. The present retrospective study reports, for the first time, a case of a cutaneous lesion by L. infantum occurring in an Italian horse. Pathological and healthy skin samples should be investigated on a larger scale to provide information on the potential clinical impact of EL in the practice, and to define the role of horses in epidemiological ZVL and CanL scenarios.

One Health Approach to Rickettsiosis: A Five-Year Study on Spotted Fever Group Rickettsiae in Ticks Collected from Humans, Animals and Environment.

The spotted fever group of Rickettsiae is a heterogeneous group of Rickettsiae transmitted by ticks, causing similar diseases in humans (spotted fever). Until recently, it was supposed that a single pathogenic tick-borne SFG Rickettsia circulated in each different geographic area and that R. conorii subsp. conorii was the SFG Rickettsiae circulating in Italy, but in the last decade, thanks to molecular diagnostic, several different Rickettsia species, previously not considered pathogenic for decades, have been isolated from ticks and definitively associated to human disease, also in Italy. The present survey was carried out with the aim of investigating the presence of different SFG Rickettsia species in a geographic area where no information was available. Ticks collected from animals submitted to necropsy, removed from humans in local hospitals and collected from the environment were identified and tested by PCR for Rickettsia spp. based on the gltA gene, and positive PCR products were sequenced. A total of 3286 ticks were collected. Fifteen tick species were recognized, the most represented (79.52%) species in the collection was Ixodes ricinus, followed by Rhipicephalus sanguineus (9.13%). The overall prevalence of Rickettsia infection was 7.58%. Eight species of Rickettsia were identified, the most frequent was R. monacensis (56%), followed by R. helvetica (25.50%). Noteworthy, is the detection in the present study of Rrhipicephali, detected only twice in Italy. These are the first data available on SFG Rickettsiae circulation in the study area and they can be considered as starting point to assess the possible risk for humans.

Molecular Survey on Rickettsia spp., Anaplasma phagocytophilum, Borrelia burgdorferi Sensu Lato, and Babesia spp. in Ixodes ricinus Ticks Infesting Dogs in Central Italy.

Dogs are a common feeding hosts for Ixodes ricinus and may act as reservoir hosts for zoonotic tick-borne pathogens (TBPs) and as carriers of infected ticks into human settings. The aim of this work was to evaluate the presence of several selected TBPs of significant public health concern by molecular methods in I. ricinus recovered from dogs living in urban and suburban settings in central Italy. A total of 212 I. ricinus specimens were collected from the coat of domestic dogs. DNA was extracted from each specimen individually and tested for Rickettsia spp., Borrelia burgdorferi sensu lato, Babesia spp., and Anaplasma phagocytophilum, using real-time and conventional PCR protocols, followed by sequencing. Sixty-one ticks (28.8%) tested positive for TBPs; 57 samples were infected by one pathogen, while four showed coinfections. Rickettsia spp. was detected in 39 specimens (18.4%), of which 32 were identified as Rickettsia monacensis and seven as Rickettsia helvetica. Twenty-two samples (10.4%) tested positive for A. phagocytophilum; Borrelia lusitaniae and Borrelia afzelii were detected in two specimens and one specimen, respectively. One tick (0.5%) was found to be positive for Babesia venatorum (EU1). Our findings reveal the significant exposure of dogs to TBPs of public health concern and provide data on the role of dogs in the circulation of I. ricinus-borne pathogens in central Italy.

Nontoxigenic Vibrio parahaemolyticus strains causing acute gastroenteritis.

We investigated the virulence properties of four Vibrio parahaemolyticus strains causing acute gastroenteritis following consumption of indigenous mussels in Italy. The isolated strains were cytotoxic and adhesive but, surprisingly, lacked tdh, trh, and type three secretion system 2 (T3SS2) genes. We emphasize that nontoxigenic V. parahaemolyticus can induce acute gastroenteritis, highlighting the need for more investigation of the pathogenicity of this microorganism.

Unusual case of necrotizing fasciitis caused by Vibrio cholerae O137.

We report a case of necrotizing fasciitis caused by Vibrio cholerae O137 in an immunocompromised 49-year-old man. The infection was acquired following a minor traumatic injury and exposure to seawater during the summer of 2009 in Italy. Although highly immunocompromised, the patient survived. The strain was cytotoxic, invasive, and adhesive and contained a fragment of the El Tor-like hemolysin (El Tor hlyA) gene.

Putative virulence properties of Aeromonas strains isolated from food, environmental and clinical sources in Italy: a comparative study.

The distribution of virulence properties in 142 strains of Aeromonas isolated from diarrhoeic patients, food and surface water in Italy and identified by biochemical and molecular methods was investigated. The virulence properties studied were the presence of genes for the aerolysin (aerA), heat-stable cytotonic enterotoxin (ast), heat-labile cytotonic enterotoxin (alt), cytotoxic enterotoxin (act); and cytotoxicity for Vero cells and adhesion on Hep-2 cells. A. hydrophila and A. caviae were the species most commonly isolated from clinical and environmental samples (9/30; 30.0% and 5/27; 18.5%, respectively) while mesophilic A. salmonicida was most common in food samples (19/80; 23.7%). Out of 142 strains, 86 (60.6%) were positive for at least one of the virulence properties. All the toxin genes were present in 4/18 (22.3%) of clinical strains. Most of the food isolates (54/55; 98.2%) were cytotoxic and most of the environmental strains (12/13; 92.3%) were adhesive. The aerA gene was present in most toxigenic strains (72/86; 83.7%), irrespective of their origin. The growth temperature affected the expression of cytotoxicity and adhesivity. Aeromonas strains from food and surface water frequently had toxin gene patterns similar to those of clinical strains and expressed virulence properties at human body temperature. These findings indicate that aeromonads have the potential to cause human illness and confirm the role of food and water as vehicles for Aeromonas diseases.

Vibrio parahaemolyticus-associated gastroenteritis in Italy: persistent occurrence of O3:K6 pandemic clone and emergence of O1:KUT serotype.

We report 2 cases of O3:K6 and O1:KUT Vibrio parahaemolyticus gastroenteritis associated with consumption of local mussels in Italy in 2008. Serotypic, antibiogram, toxigenic, and pulsed-field gel electrophoresis patterns of these strains were compared to those of other isolates collected from local clinical and seafood samples in 2007 to 2008. We underline the recurrent presence of O3:K6 pandemic clone and the emergence of trh-positive O1:KUT serotype in Italy.

Prevalence, serotyping and molecular characterization of Vibrio parahaemolyticus in mussels from Italian growing areas, Adriatic Sea.

The aims of this study were to investigate the prevalence of total and pathogenic Vibrio parahaemolyticus strains in Italian mussels from different geographical areas of the Adriatic Sea and to determine their serotypes, toxigenic profiles and pandemic potential. Out of 559 samples analysed during 2007, 65 (11.6%) were positive for V. parahaemolyticus. None of the isolates had the genes for thermostable direct haemolysin (tdh) and pandemic marker (toxRS), while five strains (7.7%) had that for TDH-related haemolysin (trh). Regarding geographical location of the toxigenic strains, three were from the Adriatic coast of Puglia, one from Veneto, and one from the Marches. The trh-positive V. parahaemolyticus isolates from Puglia belonged to O1:KUT (2/3) and O1:K37(1/3) serotypes, the trh-positive isolate from the Marches to OUT(O untypeable):KUT serotype, and that from Veneto to O3:KUT. The prevalence of trh-positive V. parahaemolyticus obtained from mussels in this study was higher respect to that reported in previous studies from other European and Extraeuropean countries. The Health Authorities should be more aware of the epidemiological role of environmental V. parahaemolyticus in local food-borne diseases, and increase the microbial surveillance on these microorganisms isolated from shellfish.

Prevalence and virulence properties of non-O1 non-O139 Vibrio cholerae strains from seafood and clinical samples collected in Italy.

Seafood and clinical samples collected in Italy during 2006 were analyzed to evaluate prevalence, serological and virulence properties of non-O1 non-O139 Vibrio cholerae (NCV) isolates. Biochemical and serological characterization of the strains was performed by standardized procedures while virulence properties of NCVs were assayed by molecular, in vivo and in vitro toxicological methods. Of the 300 seafood samples examined, including mussel, cod, mackerel, anchovy, clam, prawn and cuttlefish, 5.6% were positive for NCVs: 4.7% and 8.5% from local and imported seafood, respectively. The prevalence of NCVs was highest in prawn (16.6%) and mussel (7.7%). Of 58 hospitalized patients that presented acute diarrhea, 3.4% eliminated NCVs in stools 24-48 h after consumption of seafood. All NCVs had ToxR and hlyAET genes but lacked ctxA, zot, and tcpA genes. One isolate from prawn had stn/sto gene. All strains were hemolytic, cytotoxic, and able to induce intestinal and extraintestinal effects on the suckling mouse model. Our results confirm that non-toxigenic NCVs that express the gene encoding El Tor-like hemolysin can be isolated from patients suffering a cholera-like syndrome after consumption of seafood. This evidence along with the virulence and enteropathogenicity of all the ctxA(-) tcpA(-) zot(-) stn/sto(-) hlyAET(+) NCV isolates in the experimental model, suggest that El Tor-like hemolysin may play an important role in human pathogenesis. Moreover, the isolates from seafood showed molecular, biological and enzymatic patterns similar to those isolated from clinical samples, underlining that environmental NCVs are potentially able to induce human infections and confirming the important role of seafood as a vehicle of V. cholerae diseases.