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It is well understood that Salmonella is carried by animals and in majority of cases as asymptomatic hosts. Surveillance efforts have focused on the role of agriculture and contamination points along the food chain as the main source of human infection; however, very little attention has been paid to the contribution of wildlife in the dissemination of Salmonella and what effect anthropogenic sources have on the circulation of antibiotic resistant Salmonella serovars in wildlife species. A purposive survey was taken of large corvids roosting yearly between November and March in Europe and North America. Two thousand and seven hundred and seventy-eight corvid faecal specimens from 11 countries were submitted for Salmonella spp. culture testing. Presumptive positive isolates were further serotyped, susceptibility tested and analysed for antibiotic resistance genes. Overall, 1.40% (39/2778) (CI = 1.01, 1.90) of samples were positive for Salmonella spp. Salmonella Enteritidis was the most prevalent serovar followed by S. Infantis, S. Montevideo and S. Typhimurium. No significant difference (P > 0.05) was found in the proportion of Salmonella recovered in Europe versus North America. The most variability of serovars within a site was in Kansas, USA with five different serovars recovered. European sites were significantly more likely to yield Salmonella resistant to more than one antibiotic (OR 71.5, P < 0.001, CI = 3.77, 1358) than North American sites, where no resistance was found. Resistance to nalidixic acid, a quinolone, was recovered in nine isolates from four serovars in four different sites across Europe. Large corvids contribute to the transmission and dissemination of Salmonella and resistance genes between human and animal populations and across great distances. This information adds to the knowledge base of zoonotic pathogen prevalence and antibiotic resistance ecology in wild birds., (© 2014 Blackwell Verlag GmbH.)

Aim: To examine surface water from a pond in the northeastern part of the Czech Republic and young black-headed gulls (Larus ridibundus) nesting on the same pond for the presence of antibiotic-resistant Salmonella and Escherichia coli., Methods and Results: A total of 16% (n = 87) of water and 24% (n = 216) of gull samples yielded Salmonella. Salmonella Enteritidis PT8 and PT4 were the most prevalent. Antibiotic resistance was found in 12% (n = 14) of water and 28% (n = 51) of gull salmonellae. Escherichia coli were found in 83 (95%) and 213 (99%) of pond water and gull samples, respectively. Totals of 18% (n = 83) of water and 28% (n = 213) of gull E. coli isolates were resistant to antimicrobial agents tested. Class 1 integrons were found in 21% (n = 14) of water and 15% (n = 60) of gull antibiotic-resistant E. coli isolates. Class 2 integrons and extended-spectrum beta-lactamase-producing E. coli isolates (with bla(CTX-M-1), bla(CTX-M-15)-like, bla(SHV-2) and bla(SHV-12)) were found in 13% (eight positive, n = 60 gull-resistant E. coli isolates) and 3% (seven positive, n = 216 gull E. coli isolates) of gull isolates, respectively. Antibiotic-resistant E. coli isolates with identical pulsed field gel electrophoresis (PFGE) patterns were found in either gulls or water, but not both. Salmonellae of the same serotype and PFGE profile were found in both gulls and water., Conclusion: A high prevalence of antibiotic-resistant salmonellae and E. coli were found in both pond water and in sympatric black-headed gulls., Significance and Impact of the Study: Intensive contamination of pond surface water by antibiotic-resistant E. coli and salmonellae was documented. Black-headed gulls were identified as important reservoirs of antibiotic-resistant salmonellae and E. coli, including extended-spectrum beta-lactamase-producing isolates.

In 1984-1994 black-headed gulls (Larus ridibundus) from various localities in the Czech Republic were examined to assess the incidence of salmonellae. A total of 99 eggs from two nest colonies were examined. No salmonellae were detected. In examinations of 740 young birds from three colonies the total prevalence was 19.3%. In full grown gulls (number of examined birds 189) from five localities the total prevalence of salmonellae was 4.2%. In water specimens near the nest colonies, other habitats of the gulls and from soil specimens from one nest colony (throughout the year) salmonellae of the same serotypes as in gulls were isolated. The young birds contaminate surface waters with salmonellae. The importance of adult birds as a source of infection is much smaller. Only for the young of aquatic birds (fowl or free living) gulls could be an important source of salmonella infections. The presence of salmonellae in gulls is due to contamination of surface waters and the surroundings of nest colonies with salmonellae.

In 1984-1991, the incidence of salmonellas was studied in wild birds from various sites in the Czech Republic. On an agricultural farm with salmonellosis in calves, salmonellae were isolated from eight birds (seven Passer domesticus, one Serinus serinus) of 31 birds examined. On various agricultural farms with no salmonellosis in farm animals, salmonellae were found in two birds (Columba livia f. domestica) of 2186 birds examined. Of 35 birds caught at a municipal waste-dump site, salmonellae were isolated from one specimen (Larus canus). No salmonellae were found in birds living in reed growths and in various military training areas (557 and 116 birds examined, respectively). In black-headed gulls (Larus ridibundus) from various areas with bodies of water, salmonellae were found in 4.2% of 189 adults and 19.2% of 740 non-flying young examined. S. typhimurium was the most common serotype isolated from gulls. Phage type 141 [corrected] represented 32% of 48 phage-typed strains. This study shows a relationship between the contamination of the environment with salmonellae and their incidence in wild birds.

The occurrence of salmonellae was investigated in 1011 cloacal smears of 21 species of wild birds caught at the locality of Hermanický rybník near Ostrava. Salmonella typhimurium serotype was isolated from one of the 23 laughing gulls (Larus ridibundus) which were examined; this corresponds to a 4.3% invasion frequency. The result of the examination of all other birds was negative. On the basis of the results of this study and the results published by other authors, laughing gull can be considered as a possible source of salmonellae for farm animal stocks, particularly water fowl. It is recommended that laughing gull should be taken into consideration when seeking, for diagnostic purposes, the sources of salmonellae from which water fowl are invaded.

Aims: To characterize antibiotic resistant Escherichia coli and Salmonella isolates in rooks wintering in the Czech Republic. Methods and Results: Three hundred and sixty-three faeces samples from rooks were examined for antibiotic resistant Escherichia coli and Salmonella. Altogether 13.7% E. coli isolates were resistant to antimicrobial agents tested. The dominant type of resistance was to tetracycline. Resistant E. coli isolates were examined for antibiotic resistance genes and class 1 integrons. Five of 29 antibiotic resistant isolates possessed the int1 gene. Nine Salmonella isolates (2.5%) were found in rook faeces. All the isolates belonged to serotype Salmonella enterica serovar Enteritidis phage type PT8 and PT23. Conclusions: The study suggests that rooks can be infected by antibiotic resistant E. coli and Salmonella isolates, probably reflecting the presence of such isolates in their sources of food and/or water in the environment. Significance and Impact of the Study: Rooks can serve as reservoirs and vectors of antibiotic resistant E. coli and Salmonella isolates and potentially transmit these isolates over long distances. [ABSTRACT FROM AUTHOR]

Salmonella were isolated from black-headed gulls ( Larus ridibundus) in six locations in the Czech Republic from 1984 to 2005 (Chropyně and Nymburk in 1984–1986; Nové Mlýny, Bartošovice, and Hodonín in 1991–1994; and Nové Mlýny, Bartošovice, and Ostrava in 2005). Antimicrobial susceptibility was determined in 12 antimicrobial drugs using disk diffusion. Although 95% of Salmonella isolates (197 out of 207) were pansusceptible, the prevalences of resistance increased significantly from 1 (2%) out of 59 isolates in 1984–1986 and 3 (3%) out of 100 isolates in 1991–1994 to 6 (13%) out of 48 isolates in 2005. Furthermore, in 2005, two isolates were nalidixic acid-resistant and one isolate was multidrug-resistant Salmonella Typhimurium DT 104. These findings suggest that the occurrence of salmonellae in black-headed gulls depends to a large extent on the contamination where the gulls feed and possibly reflects the dissemination of these strains among farm animals and humans. Black-headed gulls may also become infected with resistant Salmonella and thus pose a potential risk of Salmonella contamination of surface water and animal feeds, and consequently dissemination. [ABSTRACT FROM AUTHOR]