Salmonella in the wildlife-human interface

A 5′ nuclease duplex real-time polymerase chain reaction (PCR) assay was developed and validated with various food products for the specific and fast detection of Salmonella spp. in food. The assay used previously published primers in combination with a newly developed probe targeting the invA gene. An internal amplification control, which is coamplified in a duplex PCR, was included in the assay. The analysis of 1,934 natural food samples with real-time PCR and the cultural method in parallel resulted in a relative accuracy of 100% and 99.84% respectively, depending on the enrichment procedure in which buffered peptone water and selective enrichment in Rappaport–Vassiliadis (RV) broth were employed. The duplex real-time PCR assay has proven to be a specific, sensitive and fast screening method for Salmonella spp. in food. The overall analysis time of the PCR method was approximately 28 h, in contrast to 4 to 5 days with conventional Salmonella diagnostics. The developed assay has been shown to be a reliable diagnostic tool for use in routine analysis. It has been validated thoroughly and has become an official method in Germany for the detection of Salmonella spp. in food.

Validation of a Duplex Real-Time PCR for the Detection of Salmonella spp. in Different Food Products

Several studies have shown that migratory birds play an important role in the ecology, circulation and dissemination of pathogenic organisms. In October 2006, a health status evaluation was performed on a large population of migratory birds passing through the territory of Ustica (Italy), an island located on the migration route of many species of birds to Africa, and various laboratory tests were conducted. In total, 218 faecal swabs and the internal organs of 21 subjects found dead in nets were collected for bacteriological and virological examination, including avian influenza and Newcastle disease. In addition, 19 pooled fresh faecal samples were collected for mycological examination. The bacteriological analysis produced 183 strains belonging to 28 different species of the Enterobacteriaceae family. In particular, Salmonella bongori, Yersinia enterocolitica and Klebsiella pneumonia strains were isolated. Almost all of the isolates were susceptible to sulphamethoxazole/trimethoprime (99.4%), cefotaxime (98.9%), nalidixic acid (96.7%), chloramphenicol (95.6%), and tetracycline (93.4%). Alternatively, many strains were resistant to ampicillin (42.6%), amoxicillin-clavulanic acid (42.6%), and streptomycin (43.7%). According to reverse transcriptase-polymerase chain reaction analysis, all of the samples were negative for the M gene of avian influenza virus. Moreover, isolation tests conducted on specific pathogen free eggs were negative for avian influenza and Newcastle disease. Several hyphomycetes and yeasts belonging to different genera were present in the specimens, and Cryptococcus neoformans was observed in a pooled faecal sample. Antibiotic resistance in wildlife can be monitored to evaluate the impact of anthropic pressure. Furthermore, migratory birds are potential reservoirs of pathogenic agents; thus, they can be regarded as sentinel species and used as environmental health indicators.

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Pathogenic microorganisms carried by migratory birds passing through the territory of the island of Ustica, Sicily (Italy)

Livestock meat and offal contribute significantly to human nutrition as sources of high-quality protein and micronutrients. Livestock products are increasingly in demand, particularly in low- and middle-income settings where economies are growing and meat is increasingly seen as an affordable and desirable food item. Demand is also driving intensification of livestock keeping and processing. An unintended consequence of intensification is increased exposure to zoonotic agents, and a contemporary emerging problem is infection with Campylobacter and Salmonella spp. from livestock (avian and mammalian), which can lead to disease, malabsorption and undernutrition through acute and chronic diarrhoea. This can occur at the farm, in households or through the food chain. Direct infection occurs when handling livestock and through bacteria shed into the environment, on food preparation surfaces or around the house and surroundings. This manuscript critically reviews Campylobacter and Salmonella infections in animals, examines the factors affecting colonization and faecal shedding of bacteria of these two genera as well as risk factors for human acquisition of the infection from infected animals or environment and analyses priority areas for preventive actions with a focus on resource-poor settings.

Infection, colonization and shedding of Campylobacter and Salmonella in animals and their contribution to human disease: A review

Wild birds have been considered to be reservoirs of enteric human pathogens and vectors of resistance dissemination to the environment. During annual migration, they potentially play a role in the epidemiology of human associated zoonoses. The aim of this study was to investigate the frequency of isolation and antimicrobial susceptibility profiles of Enterobacteriaceae members isolated from cloacal swabs of common European wild birds. Fifty-five cloacal swabs were taken during birds' entrance evaluation in a rescue centre for injured wild birds in the Province of Messina (Sicily, Italy). All samples were examined for the presence of members of the family Enterobacteriaceae using standard methods and on the isolated strains antibiotic susceptibility testing was performed. Eighty three Enterobacteriaceae strains were isolated from raptors, waterbirds and passerines. The bacterial species isolated were: Escherichia coli, Proteus mirabilis, Proteus vulgaris, Citrobacter freundii, Enterobacter cloacae, Klebsiella oxytoca, Salmonella Typhimurium, Escherichia vulneris, Enterobacter amnigenus biogroup 2, Salmonella Duesseldorf and Hafnia alvei. The isolates showed significant frequencies of antibiotic resistance. Multiresistance to three or more groups of antibiotics also occurred. None of them have shown a phenotypic Extended Spectrum Beta Lactamase (ESBL) profile.

Antimicrobial resistance patterns of Enterobacteriaceae in European wild bird species admitted in a wildlife rescue centre.

Suggested citation for this article: Foti M, Daidone A, Aleo A, Pizzimenti A, Giacopello C, Mammina C. Salmonella bongori 48:z35:– in migratory birds, Italy. Emerg Infect Dis [serial on the Internet]. 2009 Mar [date cited]. Available from http://www.cdc.gov/EID/content/15/3/502.htm

Alessia Pizzimenti

Papers

Salmonella bongori 48:z35:– in Migratory Birds, Italy