A new mutation in mgrb mediating polymyxin resistance in Klebsiella variicola.

Polymyxin resistance is a public health concern - present in humans, animals and the environment - caused by chromosomal-encoding or plasmid-encoding mechanisms. Chromosomal alterations in MgrB are frequently detected in Klebsiella spp., but not yet reported and characterised in Klebsiella variicola (K. variicola). This study performed microbiological and genomic characterisation of three polymyxin-resistant K. variicola isolates (M14, M15 and M50) recovered from the microbiota of migratory birds in Brazil. The isolates were submitted to SpeI-PFGE, broth microdilution and whole genome sequencing using Illumina MiSeq for analysis of genetic relatedness, sequence typing and detection of antimicrobial-resistance genes. K. variicola isolates belonged to two clones, and susceptibility tests showed resistance only for polymyxins. Sequences of chromosomal two-component systems (PmrAB, PhoPQ, RstAB, CrrAB) and MgrB were evaluated by blastN and blastP against a polymyxin-susceptible K. variicola (A58243), and mutations with biological effect were checked by the PROVEAN tool. K. variicola isolates belonged to two clones, and susceptibility tests showed resistance for polymyxins. In M14 and M15, phoQ deleterious mutations (D90N, I122S and G385S) were identified, while an mgrB variant containing a single deletion (C deletion on position 93) leading to the production of a non-functional protein was detected in M50. mgrB complementation studies showed restoration of polymyxin susceptibility (64 to ≤ 0.25 mg/L) as a wild-type mgrB was inserted into the mgrB-deficient M50. This study confirmed the role of a non-functional mgrB variant in conferring polymyxin resistance, stressing the role of this regulator in K. variicola and drawing attention to novel polymyxin resistance mechanisms emerging in wildlife.

Salmonella in Raptors and Aquatic Wild Birds in Chile.

Salmonella enterica is one of the main causes of gastrointestinal disease worldwide. Wild birds are capable of harboring a variety of Salmonella serovars, which could have an important role in the epidemiology of salmonellosis in humans and production animals. We tested 519 fecal samples from raptors and aquatic birds from different regions of central (three rehabilitation centers for wildlife and the coastal area) and southern areas of Chile for Salmonella. All samples were obtained in 2015 and 2017, covering all four seasons. Salmonella was isolated from 12 of the 519 samples (2%) analyzed, from two carnivorous birds, four birds with generalist habits, and six waterfowl. Among the isolates obtained, one showed resistance to gentamicin, and one showed a multidrug-resistance phenotype, with resistance to ampicillin, ceftriaxone, ciprofloxacin, chloramphenicol, streptomycin, gentamicin, kanamycin, trimethoprim-sulfamethoxazole, and tetracycline. These results demonstrated the importance of characterizing Salmonella in wild birds because previous studies have shown genetic and phenotypic evidence suggesting interspecies transmission of Salmonella enterica that is resistant to antimicrobials between humans and wild and domestic birds.

On the Emergence of Cryptococcus gattii in the Pacific Northwest: Ballast Tanks, Tsunamis, and Black Swans.

The appearance of Cryptococcus gattii in the North American Pacific Northwest (PNW) in 1999 was an unexpected and is still an unexplained event. Recent phylogenomic analyses strongly suggest that this pathogenic fungus arrived in the PNW approximately 7 to 9 decades ago. In this paper, we theorize that the ancestors of the PNW C. gattii clones arrived in the area by shipborne transport, possibly in contaminated ballast, and established themselves in coastal waters early in the 20th century. In 1964, a tsunami flooded local coastal regions, transporting C. gattii to land. The occurrence of cryptococcosis in animals and humans 3 decades later suggests that adaptation to local environs took time, possibly requiring an increase in virulence and further dispersal. Tsunamis as a mechanism for the seeding of land with pathogenic waterborne microbes may have important implications for our understanding of how infectious diseases emerge in certain regions. This hypothesis suggests experimental work for its validation or refutation.

Class 1 integrons as predominant carriers in Escherichia coli isolates from waterfowls in Hainan, China.

This study was conducted to determine the prevalence of integrons and associated gene cassettes in Escherichia coli (E. coli) isolates from waterfowls in Hainan, China. The antimicrobial resistance profile of the isolates was examined by using disc diffusion test. In addition, PCR, RFLP, plasmid replicon typing and DNA sequencing analyses were used for the characterization of integrase genes (class 1, 2 and 3) and associated gene cassettes. Approximatively, 90% of the isolates were positive for the integrase genes by PCR. Specifically, class 1 and class 2 integrons were found in 252 (81%) and 7 (2.3%) strains, respectively. While 21 (6.7%) isolates were positive for both class 1 and class 2 integrons. However, none of the isolate was positive for the class 3 integrons. In addition, 5 various cassette arrays, dfrA1-orfC, aadA2, aadA1, dfrA1-aadA1, and dfrA1-orfC- aadA1, were found within the variable regions (VRs) of class 1 integron isolates. While only single cassette array, dfrA1-sat2- aadA1, was identified within VRs of class 2 integron isolates. We identified incF plasmid as the most common plasmid type, which was detected in 81 of 243 VRs containing isolates. This study is the first report showing the baseline characteristics of integrons in E. coli isolates from waterfowls in Hainan, China. Our results provide evidence of the waterfowl birds as a reservoir of class 1 and class 2 integrons carrying antibiotic resistance gene cassettes. Therefore, strict preventive measures should be taken to avoid the spread of mobile genetic resistance elements in waterfowls in China.

Carriage of Campylobacter, Salmonella, and Antimicrobial-Resistant, Nonspecific Escherichia coli by Waterfowl Species Collected from Three Sources in Southern Ontario, Canada.

Wild birds are considered a potential source of zoonotic pathogens. We report on the occurrence of Campylobacter, Salmonella, and antimicrobial-resistant, nonspecific Escherichia coli in ducks, grebes, and swans obtained by convenience while conducting related research with Canada Geese (Branta canadensis). Samples were obtained in southern Ontario, Canada, between 2013 and 2015 from hunter-caught birds, birds submitted for postmortem diagnosis, and fresh feces from live birds in parks. A secondary objective was to characterize Campylobacter genotypes using comparative genomic fingerprinting. Salmonella and E. coli isolates were tested for susceptibility to 15 antimicrobials using the Canadian Integrated Program for Antimicrobial Resistance Surveillance test panel. A total of 71 samples were collected from 15 different waterfowl species. We detected Campylobacter, Salmonella, and E. coli in 17, 3, and 84% of samples, respectively. Ten unique Campylobacter subtypes were identified, some of which had been identified previously in water, poultry, waterfowl, and human clinical cases. Both Salmonella isolates were pansusceptible and 15% of E. coli isolates were resistant to at least one antimicrobial, including resistance to antimicrobials of highest importance to human health. Source attribution studies should examine the role of waterfowl in the dissemination of these pathogens.

Association between submerged aquatic vegetation and elevated levels of Escherichia coli and potential bacterial pathogens in freshwater lakes.

Fecal indicator bacteria such as Escherichia coli have been reported to persist and potentially grow in a wide variety of secondary habitats, such as water, beach sand, sediment, periphyton and some algae. However, little is known about their association with submerged macrophytes and how this may influence water quality. In this study, we examined the association of E. coli and potential bacterial pathogens with Eurasian watermilfoil (EWM), an invasive, submerged, macrophyte that has spread across thousands of lakes in North America. EWM samples were collected from 10 lakes in Minnesota, once a month, for six consecutive months from early summer to late fall. Microbiota associated with EWM were examined using membrane filtration, quantitative PCR targeting various bacterial pathogens and host-associated marker genes, and high-throughput DNA sequencing. E. coli densities were generally elevated on EWM samples, and peaked during warmer months. Moreover, our results showed that EWM could serve as a temporal source for transmission of microbiota to the water column. Several potential pathogenic groups, including Aeromonas, Enterobacteriaceae, and Clostridium were present in significantly greater relative abundance on EWM than in water, and waterfowl was predicted to be the major source of fecal contamination. These findings have water quality implications with respect to the potential for submerged macrophytes to harbor and disperse E. coli and other bacterial pathogens in a large number of waterbodies.

Epidemiology of Campylobacter, Salmonella and antimicrobial resistant Escherichia coli in free-living Canada geese (Branta canadensis) from three sources in southern Ontario.

Antimicrobial resistant bacteria and zoonotic pathogens have previously been isolated from Canada geese. We examined the prevalence of three enteric bacteria (i.e. Campylobacter, Salmonella, Escherichia coli) among Canada geese from three sampling sources in southern Ontario from 2013 through 2015. Samples were obtained by convenience from hunting groups, diagnostic birds submitted for post-mortem, and fresh faeces from live birds in parks. Escherichia coli isolates were isolated and tested for susceptibility to 15 antimicrobials using the Canadian Integrated Program for Antimicrobial Resistance Surveillance test panel. The prevalences of Salmonella, Campylobacter and E. coli were 0%, 11.2% and 72.6%, respectively. Among E. coli isolates, 7.9% were resistant to ≥1 class of antimicrobials and 5.6% were resistant to ≥2 classes of antimicrobials, with some including resistance to antimicrobials of highest importance in human medicine. A significant association between season and E. coli resistance among samples from live birds was noted; summer samples had no resistant E. coli isolates, whereas spring samples demonstrated the highest prevalence of E. coli resistant to ≥1 class of antimicrobials (20.0%) among all sources. In addition, Campylobacter coli were only isolated from the spring faecal samples. Flock-level clustering was an important statistical consideration, as flock was a significant random effect in all but two of our models. Detection of Campylobacter and antimicrobial resistant E. coli from Canada geese suggests that these birds may play a role in disseminating these organisms within the environment.

Characterization of pathogenic Enterococcus cecorum from different poultry groups: Broiler chickens, layers, turkeys, and waterfowl.

Enterococcus cecorum (EC) is known as a commensal in the intestines of mammals and birds. However, it has been described as an emerging pathogen in poultry industry worldwide. The aim of this study was to analyze and compare EC isolated from clinical material collected from poultry groups with different production purposes. The genetic diversity among pathogenic EC in relation to each specific poultry type was examined. In total, 148 isolates from independent infection outbreaks (2011-2016) were used: 76 broiler chickens (CB), 37 broiler breeders (BB), 23 layers (CL), 7 waterfowl (W) and 5 turkey (T) flocks (1 isolate/1 flock). We provided age ranges at diagnosis of EC-infection for 5 poultry groups. Isolates obtained from CB were significantly more frequently retrieved from bone marrow, joints, spine, and contrary to BB, CL less frequently retrieved from respiratory system. The study showed differences between EC of various poultry types in relation to 10/32 (31.3%) biochemical parameters. EC isolates from CB were significantly more often positive for ßGAL, ßNAG, MLZ, and less often positive for PAL and ßMAN than isolates from other poultry types. However, BB and W isolates showed higher ability to metabolise mannitol than CB, CL, and T. CB isolates showed lower ability to survive at 60°C. Only chicken EC-isolates harbored virulence genes: CB (8.1%) > BB (3.4%) > CL (2%). No specific pulsotype of EC was associated with a specific poultry. One or several various (up to 6) genetic types of EC may be involved in outbreaks in CB flocks within one year in one region. Outbreaks reported in following years in the same region were usually caused by a distinct set of EC-genetic types. PFGE results indicated at the genetic heterogeneity among pathogenic isolates involved in outbreaks in relation to each poultry type. To our best knowledge, this is the first study which provides a comparison between clinical EC from 5 poultry groups. The study provides a new insight into EC as pathogen of different bird species. The obtained data may be useful in further studies on EC-infections more focused on a specific type of poultry.

Prevalence of Salmonella among waterfowl along the Texas Gulf coast.

Migratory waterfowl may play a role in the ecology and transmission of zoonotic pathogens, given their ability to travel long distances and their use of varied habitats. Our objectives were to estimate the prevalence of Salmonella among waterfowl along the Texas Gulf coast and to characterize the isolates. Faecal samples were collected from hunter-harvested waterfowl at four wildlife management areas from September through November, 2016. Standard bacteriologic culture methods were used to isolate Salmonella from samples, and isolates were characterized by serotyping and anti-microbial susceptibility testing. The apparent prevalence of faecal Salmonella shedding was 0.5% (2/375). Serotypes identified were Thompson and Braenderup, and both isolates were susceptible to all anti-microbial agents tested. Although faecal contamination of agricultural fields or surface waters could serve as a potential source of zoonotic Salmonella transmission, waterfowl along the Gulf coast during the fall hunting season appear to pose minimal risk.

Characterising the interspecific variations and convergence of gut microbiota in Anseriformes herbivores at wintering areas.

Microorganisms in vertebrate guts have been recognized as important symbionts influencing host life. However, it remains unclear about the gut microbiota in long-distance migratory Anseriformes herbivores, which could be functionally important for these wetland-dependent animals. We collected faeces of the greater white-fronted goose (GWFG), bean goose (BG) and swan goose (SG) from Shengjin Lake (SJL) and Poyang Lake (PYL) in the Yangtze River Floodplain, China. High-throughput sequencing of 16S rRNA V4 region was employed to depict the composition and structure of geese gut microbiota during wintering period. The dominant bacterial phyla across all samples were Firmicutes, Proteobacteria and Actinobacteria, but significant variations were detected among different goose species and sampling sites, in terms of α diversity, community structures and microbial interactions. We found a significant correlation between diet and the microbial community structure in GWFG-SJL samples. These results demonstrated that host species and diet are potential drivers of goose gut microbiota assemblies. Despite these variations, functions of geese gut microbiota were similar, with great abundances of potential genes involved in nutrient metabolism. This preliminary study would be valuable for future, exhaustive investigations of geese gut microbiota and their interactions with host.

Virulence Genes and the Antimicrobial Susceptibility of Escherichia coli, Isolated from Wild Waterbirds, in the Netherlands and Poland.

Affiliation to four phylogroups (A, B1, B2, and D) was examined, among 190 Escherichia coli strains, collected from five, wild waterbird species, including the following: the Greylag goose-Anser anser (61) and the Canada goose-Branta canadensis (33) obtained in the Netherlands, and the Mallard-Anas platyrhynchos (38), the Mute swan-Cygnus olor (37), and the Great cormorant-Phalacrocorax carbo (21) obtained in Poland. Moreover, the prevalence of 10 virulence factors: astA, iss, iucD, irp2, papC, tsh, vat, cva/cvi, stx2f, and bfp, as well as antimicrobial susceptibility to amoxicillin, enrofloxacin, and tetracycline (minimum inhibitory concentration [MIC] using E-tests) were investigated, in the examined E. coli strains. Results demonstrated that the greatest number of E. coli strains belonged to phylogenetic groups, B1 (86 strains-45.3%) and D (49 strains-25.8%), whereas 40 (21.0%) and only 15 (7.9%) isolates were classified as being of phylogenetic groups, A and B2, respectively. Among the 10 tested virulence-associated genes, 7 genes were detected in 61 examined strains (32.1%) with highly varying frequency. Virulence profiles showed that astA, iss, and irp2 genes were detected most frequently among all examined E. coli strains, isolated from every chosen bird species. Antimicrobial susceptibility, as detected by MIC for the examined antibiotics, is variable among strains isolated from different species of birds. The aim of this study was to examine the prevalence of E. coli strains, isolated from different species of wild waterbirds and determine their potential pathogenicity to the environment, other birds, and people.

Waterbird Susceptibility to Avian Cholera at Hayward Marsh, California, USA.

We characterized past avian cholera outbreaks in waterbirds at Hayward Marsh, California, US. In 2013, we surveyed populations and determined the presence of disease using several diagnostic methods, including behavioral and physical observations, field necropsy, and bacterial culture. We compiled this information with data from previous outbreaks from 1990-2012 to compare waterbird abundance to various measures of mortality, including percentage of mortality and percentage of difference between abundance and mortality by species. We suggest that Ruddy Duck ( Oxyura jamaicensis ) have consistently suffered greater mortality from this disease than have other species at this site.

Respiratory tract infection caused by Mycobacterium bovis in a black swan (Cygnus atratus).

A 3-year-old male black swan (Cygnus atratus), belonging to a private collection, died suddenly and was subjected to post mortem examination. At necropsy, caseous exudate was observed in the lungs and air sacs; granulomatous lesions characterized by epithelioid macrophages and abundant mycobacteria were observed microscopically. Avian tuberculosis associated with Mycobacterium bovis was confirmed by bacteriologic isolation, biochemical tests and molecular methods. The organism was identified as spoligotype SB0140, which is frequently found in cattle and people in North America. In this case, interspecies transmission could have been the source of infection because the swan cohabited with cattle.

Whole-Genome Sequence Analysis and Genome-Wide Virulence Gene Identification of Riemerella anatipestifer Strain Yb2.

Riemerella anatipestifer is a well-described pathogen of waterfowl and other avian species that can cause septicemic and exudative diseases. In this study, we sequenced the complete genome of R. anatipestifer strain Yb2 and analyzed it against the published genomic sequences of R. anatipestifer strains DSM15868, RA-GD, RA-CH-1, and RA-CH-2. The Yb2 genome contains one circular chromosome of 2,184,066 bp with a 35.73% GC content and no plasmid. The genome has 2,021 open reading frames that occupy 90.88% of the genome. A comparative genomic analysis revealed that genome organization is highly conserved among R. anatipestifer strains, except for four inversions of a sequence segment in Yb2. A phylogenetic analysis found that the closest neighbor of Yb2 is RA-GD. Furthermore, we constructed a library of 3,175 mutants by random transposon mutagenesis, and 100 mutants exhibiting more than 100-fold-attenuated virulence were obtained by animal screening experiments. Southern blot analysis and genetic characterization of the mutants led to the identification of 49 virulence genes. Of these, 25 encode cytoplasmic proteins, 6 encode cytoplasmic membrane proteins, 4 encode outer membrane proteins, and the subcellular localization of the remaining 14 gene products is unknown. The functional classification of orthologous-group clusters revealed that 16 genes are associated with metabolism, 6 are associated with cellular processing and signaling, and 4 are associated with information storage and processing. The functions of the other 23 genes are poorly characterized or unknown. This genome-wide study identified genes important to the virulence of R. anatipestifer.

Feather corticosterone reveals effect of moulting conditions in the autumn on subsequent reproductive output and survival in an Arctic migratory bird.

For birds, unpredictable environments during the energetically stressful times of moulting and breeding are expected to have negative fitness effects. Detecting those effects however, might be difficult if individuals modulate their physiology and/or behaviours in ways to minimize short-term fitness costs. Corticosterone in feathers (CORTf) is thought to provide information on total baseline and stress-induced CORT levels at moulting and is an integrated measure of hypothalamic-pituitary-adrenal activity during the time feathers are grown. We predicted that CORTf levels in northern common eider females would relate to subsequent body condition, reproductive success and survival, in a population of eiders nesting in the eastern Canadian Arctic during a capricious period marked by annual avian cholera outbreaks. We collected CORTf data from feathers grown during previous moult in autumn and data on phenology of subsequent reproduction and survival for 242 eider females over 5 years. Using path analyses, we detected a direct relationship between CORTf and arrival date and body condition the following year. CORTf also had negative indirect relationships with both eider reproductive success and survival of eiders during an avian cholera outbreak. This indirect effect was dramatic with a reduction of approximately 30% in subsequent survival of eiders during an avian cholera outbreak when mean CORTf increased by 1 standard deviation. This study highlights the importance of events or processes occurring during moult on subsequent expression of life-history traits and relation to individual fitness, and shows that information from non-destructive sampling of individuals can track carry-over effects across seasons.

Cutaneous, respiratory and hepatic aspergillosis in Brazilian white Pekin mallards (Anas platyrhynchos).

Aspergillosis is one of the most frequent mycosis affecting avian species. Here is reported an outbreak of aspergillosis affecting 60-day-old white Pekin mallards (Anas platyrhynchos). About 10% of animals in a lot of 200 mallards from a commercial husbandry presented respiratory disorders and skin lesions at slaughter. Three out of 13 animals sent to diagnosis showed, simultaneously, airsacculitis, lung and liver presenting white nodules with variable diameters and elevated, yellowish brown, crusted, multifocal skin lesions located at the base of the feather follicles in the breast. Histopathological examination of lung and liver samples revealed nodules of different sizes with small areas of necrosis surrounded by intense granulomatous inflammation and the presence of fungal hyphae. The skin samples showed dermatitis surrounding a severe necrotizing folliculitis, associated with fungal hyphae. Mycological evaluation of tissues allowed the isolation of Aspergillus fumigatus from the skin samples and Aspergillus flavus from lungs and liver samples. The application of quicklime (CaO) in the litter as part of the disinfection procedures could have contributed to the development of skin lesion in the mallards, predisposing the fungal installation in the damaged site. The occurrence of cutaneous lesions associated with A. fumigatus is a rare manifestation of aspergillosis in birds, and this appears to be the first case reported in white Pekin mallards.

First identification of "Brachyspira hampsonii" in wild European waterfowl.

Anseriformes deserve special attention in the epidemiology of Brachyspira spp. because diverse Anseriformes species have been described to act as highly efficient carriers of several Brachyspira spp. that can also infect livestock. The aim of this study was to investigate the prevalence and diversity of Brachyspira spp. in waterfowl that winter in Spain. Brachyspira spp. were isolated from 51 of the 205 faecal samples collected from graylag geese and mallards in the Villafáfila Lagoons Nature Reserve (Northwestern Spain). The Brachyspira species identified through phenotyping, PCR and sequencing of the nox gene were B. pilosicoli (5.9%), B. alvinipulli (11.8%), "B. hampsonii" (19.6%), B. murdochii (23.5%) and B. innocens (39.2%). The most relevant finding of this study is the description of "B. hampsonii" in specimens from birds for the first time. Phylogenetic analysis of the nox gene sequences grouped all of the obtained "B. hampsonii" isolates into a cluster with Brachyspira strains previously identified by others as "B. hampsonii" and separated from other Brachyspira spp. isolates and reference strains. Additionally, this cluster was related to clades that grouped B. murdochii and B. innocens isolates. The identification of "B. hampsonii" was also achieved in 8 of the 10 isolates by sequencing the16S rRNA gene and tlyA gene. Regardless of the species identified, no antimicrobial resistance was observed in any of the enteropathogenic isolates recovered. This is the first description of "B. hampsonii" in European waterfowl, which might represent hosts that serve as natural reservoirs of this Brachyspira species. This finding indicates that this spirochete is not limited to North America, and its presence in wild birds in Europe poses a risk of transmission to livestock.

Classification of avian haemolytic Actinobacillus-like organisms (Bisgaard taxon 26) associated with anseriforme birds as Actinobacillus anseriformium sp. nov.

Avian haemolytic Actinobacillus-like organisms have tentatively been named Bisgaard taxon 26. Phenotypic information has been published on 65 strains of this taxon. In the current study, 31 isolates were selected for genotypic characterization. Thirty strains had the same rpoB sequence and only one strain diverged in 1 nt. The highest rpoB similarity to members of other taxa was 89.7 % to the type strain of Actinobacillus equuli subsp. haemolyticus and the similarity to the type strain of the type species, Actinobacillus lignieresii, was 88.2 %. The lowest 16S rRNA gene sequence similarity between strains of the group was determined in previous investigations to be 99.6 % and the highest similarities of 96.4 and 96.2 % outside the group were obtained to the reference strain of Actinobacillus genomospecies 2 and to the type strain of A. equuli subsp. equuli, respectively; 95.8-95.3 % similarity was obtained with the type strain of A. lignieresii. recN gene sequence similarities within the group were from 99.5 % (strains F66(T) and F64) to 99.8 % (strains F66(T) and F67) corresponding to genome similarities of 93.9-94.6 %, which are near the upper limit for species compared with other members of the Pasteurellaceae. The highest recN similarity outside the group (83.4 %) was observed to the type strain of Actinobacillus capsulatus, whereas the similarity to the type strain of A. lignieresii was 80.9 %, corresponding to genome similarities of 57.7 and 52.0 %, respectively. All isolates meet the phenotypic characters outlined for Actinobacillus (urease-, phosphatase- and porphyrin-positive, indole-negative, acid production from fructose, sucrose, maltose and dextrin). ß-Haemolysis of bovine blood is observed and isolates may demonstrate in vitro satellitic growth, referred to as V-factor or NAD requirement. Isolates have been obtained from the upper respiratory tract of web-footed birds in which they may cause sinusitis, conjunctivitis and septicaemia. Based on the characterization reported, it is proposed that the isolates belong to a novel species, Actinobacillus anseriformium sp. nov., which includes taxon 26 and a V-factor-dependent strain. The major fatty acids of the type strain are C(16 : 1)ω7c, C(14 : 0), C(16 : 0) and C(14 : 0) 3-OH and/or iso-C(16 : 1) I, corresponding to the profile observed for the type strain of A. lignieresii. Five to 12 characters separate A. anseriformium from other taxa of Actinobacillus, with Actinobacillus ureae being most closely related; A. anseriformium can be differentiated from A. ureae based on haemolysis, ß-glucosidase, and production of acid from (-)-D-sorbitol, trehalose and glycosides. The type strain of A. anseriformium is F66(T) ( = CCUG 60324(T) = CCM 7846(T)), which was isolated from conjunctivitis in a White Pekin duck.

Antibiotic-resistant Escherichia coli bacteria, including strains with genes encoding the extended-spectrum beta-lactamase and QnrS, in waterbirds on the Baltic Sea Coast of Poland.

Individual cloacal swabs of mallards (Anas platyrhynchos) and of herring gulls (Larus argentatus), as well as samples of waterbird feces obtained in 2008 and 2009, were cultivated for Escherichia coli. Isolates of E. coli were tested for susceptibilities to 12 antimicrobial agents by the disk diffusion method. Moreover, the samples were subcultivated on MacConkey agar (MCA) containing cefotaxime (2 mg liter(-1)) to detect E. coli with extended-spectrum beta-lactamase (ESBL) and subsequently on MCA supplemented with ciprofloxacin (0.05 mg liter(-1)) and MCA with nalidixic acid (20 mg liter(-1)) to isolate fluoroquinolone-resistant E. coli. PCR was used to detect specific antibiotic resistance genes. We found 9 E. coli isolates producing ESBL with bla genes: bla(CTX-M-1) (6 isolates), bla(CTX-M-9) plus bla(TEM-1b) (1 isolate), bla(CTX-M-15) plus bla(OXA-1) (1 isolate), and bla(SHV-12) (1 isolate). In the isolate with bla(CTX-M-15), the gene aac(6)-Ib-cr was also detected. The bla genes were harbored by transferable plasmids of the IncN and IncI1 groups. Nine quinolone-resistant E. coli isolates with qnrS genes were found and characterized. The gene qnrS was associated with a Tn3-like transposon on the IncX1 plasmid together with bla(TEM-1) in two isolates. The gene qnrS was also harbored by conjugative plasmids of the IncN and IncX2 groups. Even if populations of wild birds are not directly influenced by antibiotic practice, we have demonstrated that antibiotic-resistant E. coli strains, including strains with various ESBL and qnrS genes, are found in the feces of wild birds on the coast of the Baltic Sea in Poland.