HEALTH ASSESSMENT OF CAPTIVE BEARDED VULTURES (GYPAETUS BARBATUS) IN CATALONIA (SPAIN).

Bearded vulture (Gypaetus barbatus) populations are declining worldwide primarily due to anthropogenic factors. A captive breeding program has been established in Spain, a country with one of the largest free-living populations in Europe, to further enhance the conservation efforts of this emblematic species. However, captive vulture populations can be exposed to different risks through food, such as drug residues and antimicrobial-resistant (AMR) bacteria. Health surveillance of species involved in captive breeding programs is important to face introduction of healthy animals in situ and to obtain baseline clinical data. The objective of this study was to assess the general health status of bearded vultures held in captivity in Catalonia (northeastern Spain) by carrying out hematologic, biochemical, toxicologic, and bacteriologic analyses. A total of 16 bearded vultures were sampled; the data obtained from one vulture, with a chronic tibiotarsal fracture, were excluded from the statistical analysis. Hematologic and biochemical parameters of the bearded vultures were mostly within the range of standard values as stated in previous studies. Basal feather and serum corticosterone levels were analyzed and described for the first time in this species. A total of 15 Escherichia coli isolates were obtained that were resistant to fluoroquinolones (80%), tetracycline (60%), trimethoprim and ampicillin (40%), sulfamethoxazole (33%), and colistin (20%), with 40% of them being multidrug resistant. Three of 15 isolates were carriers of the mcr-1 gene. Only the injured bird previously treated with enrofloxacin was positive for fluoroquinolone residues. Periodic monitoring for the presence of AMR bacteria would be recommended in captive breeding programs as a preventive action to establish future therapies.

One Health Approach: Invasive California Kingsnake (Lampropeltis californiae) as an Important Source of Antimicrobial Drug-Resistant Salmonella Clones on Gran Canaria Island.

The increase in the reptile population has led to a rise in the number of zoonotic infections due to close contact with reptiles, with reptile-associated salmonellosis being particularly relevant. California kingsnake invasion not only threatens the endemic reptile population of the island of Gran Canaria (Spain) but also poses serious public health problems by spreading zoonotic pathogens and their antimicrobial resistance (AMR) to the environment. Thus, the aim of this study was to assess the occurrence, genetic diversity, and AMR among Salmonella spp. strains isolated from California kingsnakes in Gran Canaria Island (Spain). Of 73 invasive individuals captured, 20.5% carried Salmonella spp., belonging to different subspecies and serovars, with subsp. salamae as the most abundant. Pulsed-field electrophoresis showed high genetic diversity among subsp. salamae isolates, and among these, 73.3% showed resistance to at least one of the antimicrobials tested. In conclusion, the present study revealed the importance of wild invasive California kingsnakes as reservoirs of drug-resistant Salmonella spp. that could pose a direct threat to livestock and humans. Identification of drug-resistant Salmonella strains in wildlife provides valuable information on potential routes of transmission that involve risks to public and animal health.

Foodborne Pathogens at the Livestock-Wildlife-Human Interface in Rural Western Uganda.

Foodborne pathogens are an important cause of morbidity and mortality worldwide. To assess the presence of Salmonella, Campylobacter and Arcobacter spp. in livestock, wildlife, and humans from different regions across western Uganda, 479 faecal samples were tested by PCR. Salmonella and Campylobacter spp. were more frequently detected in livestock (5.1% and 23.5%, respectively) compared to wildlife (1.9% and 16.8%, respectively). Wildlife from remote areas showed lower Salmonella and Campylobacter spp. occurrence than in areas where interactions with livestock are common, suggesting that spill-over may exist from livestock or humans. Further studies are needed to better understand the transmission dynamics of these pathogens at the wildlife-livestock-human interface in western Uganda.

In a warm climate, ventilation, indoor temperature and outdoor relative humidity have significant effects on Campylobacter spp. colonization in chicken broiler farms which can occur in only 2 days.

A longitudinal study was conducted in five conventional broiler farms during a 2-year period to determine the dynamics of Campylobacter infection in a warm climate region (north-eastern Spain). Weekly sampling of 63 flocks was performed upon one-day-old chick placement, including animal and environmental samples. Campylobacter spp. detection was assessed by culture and non-culture methods. Environmental samples were also obtained from cleaned and disinfected houses prior to chick placement. Thirty-nine flocks (61.90%) became colonized during the growing period. First bird excreting Campylobacter was detected in 10-day-old chicks and the earliest a whole flock became positive was at 14 days of age, while the latest was at 39 days. Once Campylobacter was detected in chickens, the whole flock was colonized within 2-13 days. Campylobacter farm prevalence (positive flocks) ranged from 53.85% to 83.33% in four out of five farms, while the remaining farm showed a lower prevalence (38.5%). Logistic regression model showed that Campylobacter infection was more likely under higher minimal indoor temperature as well as at higher minimal outdoor relative humidity, characteristic of warm climates such as those from Mediterranean countries. Ventilation type was also significant (P = 0.021). No clear farm effect or seasonality were observed. Biosecurity improvements, specially at house level, are needed in broiler farms to prevent flock colonization and reduce the current high flock prevalence.

Eurasian griffon vultures carry widespread antimicrobial resistant Salmonella and Campylobacter of public health concern.

The global emergence of antimicrobial-resistant (AMR) strains of Salmonella and Campylobacter is a serious public health concern. Both bacteria are leading causes of human gastrointestinal foodborne infections and the two most reported zoonoses in the European Union. By feeding on livestock carcasses, especially from intensive farming, as well as on landfill sites, obligate avian scavengers can become infected with zoonotic pathogens and AMR strains, and can be considered large-scale sentinels of the environmental burden. In this study, we assessed the occurrence and AMR of Salmonella spp. and Campylobacter spp. in 218 Eurasian griffon vultures (Gyps fulvus) captured in north-eastern Spain. We isolated Salmonella from 8.1 % of individuals and Campylobacter lari from 4.7 %. Among the 10 different Salmonella serovars found, monophasic S. Typhimurium was the most frequent. Genotyping analysis revealed same strains of monophasic S. Typhimurium shared by gulls, livestock and humans. Isolates from both bacterial species presented AMR to important antimicrobials (tetracyclines, fluoroquinolones and ß-lactams). In conclusion, this study shows that Eurasian griffon vultures in north-eastern Spain are carriers of widespread AMR zoonotic Salmonella and Campylobacter. More comprehensive analyses are still needed to understand the potential risk of spill-over from those wild birds to humans.

Antimicrobial Resistant Salmonella in Chelonians: Assessing Its Potential Risk in Zoological Institutions in Spain.

Salmonella is mostly noted as a food-borne pathogen, but contact with chelonians has also been reported as a source of infection. Moreover, high levels of antimicrobial resistance (AMR) have been reported in Salmonella isolated from wild and captive reptiles. The aim of this study was to assess the occurrence of Salmonella AMR carriage by chelonians admitted to two zoological institutions in Spain, characterizing the isolates to assess the Salmonella AMR epidemiology in wildlife. To this end, 152 chelonians from nine species were sampled upon their arrival at the zoological nuclei. Salmonella identification was based on ISO 6579-1:2017 (Annex D), isolates were serotyped and their AMR analysed according to the EU Decision 2013/652. Moreover, the genetic relationship of the isolates was assessed by pulsed-field gel electrophoresis (PFGE). Results showed 19% (29/152) of the chelonians positive to Salmonella, all of them tortoises. For all isolates, 69% (20/29) were resistant and 34% (10/29) multidrug-resistant (MDR) strains. PFGE clustered isolates according to the serovar, confirming a low genetic diversity. In conclusion, this study shows a high presence of MDR Salmonella strains in tortoises at their entry into zoological nuclei. This condition highlights the need to establish Salmonella detection protocols for the entry of animals into these centres.

Chicken liver is a potential reservoir of bacteriophages and phage-derived particles containing antibiotic resistance genes.

Poultry meat production is one of the most important agri-food industries in the world. The selective pressure exerted by widespread prophylactic or therapeutic use of antibiotics in intensive chicken farming favours the development of drug resistance in bacterial populations. Chicken liver, closely connected with the intestinal tract, has been directly involved in food-borne infections and found to be contaminated with pathogenic bacteria, including Campylobacter and Salmonella. In this study, 74 chicken livers, divided into sterile and non-sterile groups, were analysed, not only for microbial indicators but also for the presence of phages and phage particles containing antibiotic resistance genes (ARGs). Both bacteria and phages were detected in liver tissues, including those dissected under sterile conditions. The phages were able to infect Escherichia coli and showed a Siphovirus morphology. The chicken livers contained from 103 to 106 phage particles per g, which carried a range of ARGs (blaTEM , blaCTx-M-1 , sul1, qnrA, armA and tetW) detected by qPCR. The presence of phages in chicken liver, mostly infecting E. coli, was confirmed by metagenomic analysis, although this technique was not sufficiently sensitive to identify ARGs. In addition, ARG-carrying phages were detected in chicken faeces by qPCR in a previous study of the group. Comparison of the viromes of faeces and liver showed a strong coincidence of species, which suggests that the phages found in the liver originate in faeces. These findings suggests that phages, like bacteria, can translocate from the gut to the liver, which may therefore constitute a potential reservoir of antibiotic resistance genes.

Zoonotic Campylobacter spp. and Salmonella spp. carried by wild boars in a metropolitan area: occurrence, antimicrobial susceptibility and public health relevance.

Campylobacter spp. and Salmonella spp. are the most reported zoonotic agents in Europe. They can be transmitted from wildlife to humans, and wild boars (Sus scrofa) can harbour them. In the Metropolitan Area of Barcelona (MAB, NE Spain) wild boars are found in urbanized areas. To assess the potential public health risk of this increasing wild boar population, we collected stool samples from 130 wild boars from the MAB (June 2015 - February 2016), to determine the Campylobacter and Salmonella occurrence and the antimicrobial susceptibility of the isolates. We also investigated the genetic diversity and virulence potential of Campylobacter. Campylobacter prevalence in wild boars was 61%. Forty six percent of wild boars carried Campylobacter lanienae, 16% carried Campylobacter coli, and 1% carried Campylobacter hyointestinalis; 4% carried both C. lanienae and C. coli, and 1% carried both C. lanienae and C. hyointestinalis. This is the first report of C. hyointestinalis in wildlife in Spain. Using pulse-field gel electrophoresis and multilocus sequence typing, we observed a high genetic diversity of Campylobacter and identified new sequence types. Thirty-three percent of C. coli and 14% of C. lanienae isolates showed a high virulence potential. All of the Campylobacter isolates analysed were resistant to at least one antimicrobial agent. Multidrug resistance was only detected in C. coli (67%). Salmonella enterica subsp. enterica was detected in four wild boars (3%) and included a S. Enteritidis serovar (1/4 wild boars) and a multidrug-resistant (ASSuT) monophasic S. Typhimurium serovar (1/4 wild boars) which is associated with human infections and pig meat in Europe. The characteristics of some of the Campylobacter and Salmonella isolates recovered suggest an anthropogenic origin. Wild boars are a reservoir of Campylobacter and have the potential to spread antimicrobial resistant Campylobacter and Salmonella in urbanized areas in the MAB.

Assessing the role of livestock and sympatric wild ruminants in spreading antimicrobial resistant Campylobacter and Salmonella in alpine ecosystems.

BACKGROUND: Livestock play an important role as reservoir of enteric pathogens and antimicrobial resistance (AMR), a health and economic concern worldwide. However, little is known regarding the transmission and maintenance of these pathogens at the wildlife-livestock interface. In this study, we assessed the occurrence, genetic diversity and AMR of Campylobacter spp. and Salmonella spp. shed by sympatric free-ranging livestock and a wild herbivore in an alpine ecosystem. RESULTS: Campylobacter spp. was isolated from 23.3 % of cattle and 7.7 % of sheep but was not isolated from horses nor Pyrenean chamois (Rupicapra pyrenaica). Campylobacter jejuni was the most frequent species. A high genetic diversity and certain host specificity of C. jejuni isolates was observed. The main AMR detected in Campylobacter isolates was to nalidixic acid (88.2 %), ciprofloxacin (82.4 %) and tetracycline (82.4 %); only 11.7 % of the isolates were pan-susceptible and 17.6 % were multi-resistant. Salmonella ser. Newport was isolated only from one Pyrenean chamois and was pan-susceptible. CONCLUSIONS: Results show that free-ranging cattle and sheep are spreaders of Campylobacter as well as their AMR strains in the alpine environment. Therefore, contaminated alpine pastures or streams may constitute a source for the dissemination of AMR enteropathogens. However, apparently, alpine wild ungulates such as Pyrenean chamois play a negligible role in the epidemiology of zoonotic enteropathogens and AMR, and are not potential bioindicators of the burden of alpine environments.

Characterization of Salmonella Frintrop isolated from dromedary camels (Camelus dromedarius).

Different studies have reported the prevalence and antibiotic resistance of Salmonella in dromedary camels and its role in camelid-associated salmonellosis in humans, but little is known about the epidemiology of Campylobacter in dromedaries. Here, we investigate the prevalence, genetic diversity and antibiotic resistance of Campylobacter and Salmonella in dromedary camels (Camelus dromedarius). A total of 54 individuals were sampled from two different dromedary farms located in Tenerife (Canary Islands, Spain). While all the samples were Campylobacter-negative, Salmonella prevalence was 5.5% (3/54), and the only serovar isolated was S. Frintrop. Pulsed-field gel electrophoresis analysis revealed a low genetic diversity, with all isolates showing a nearly identical pulsotype (similarity >95%). Our results indicate that dromedary camels could not be a risk factor for Campylobacter human infection, but seems to be a reservoir for Salmonella transmission. Since camel riding has become one of the main touristic attractions in several countries, and its popularity has increased considerably in recent years, a mandatory control, especially for zoonotic pathogens such as Campylobacter and Salmonella, should be implemented.

Occurrence and antimicrobial resistance of zoonotic enteropathogens in gulls from southern Europe.

Campylobacter spp. and Salmonella spp. are the two most frequent zoonotic bacteria involved in human enteric infections in the European Union. Both enteropathogens have been isolated from a diversity of wild birds in Northern Europe, but there is limited information about gulls as potential reservoirs in Southern Europe. A broad sampling of fledglings from nine colonies of yellow-legged gull (Larus michahellis, N = 1222) and Audouin's gull (Larus audouinii, N = 563) has been conducted in Spain and Tunisia during the late chick-rearing period. Overall, the occurrence of Campylobacter spp. and Salmonella spp. was 5.2% (93/1785, CI95%: 4.2-6.2%) and 20.8% (371/1785, CI95%: 18.9-22.7%), respectively. The most predominant Campylobacter species was C. jejuni (94.6%). A high diversity of Salmonella serovars was isolated and the most frequent were those also reported in human outbreaks, such as Salmonella Typhimurium. A high proportion of Campylobacter and Salmonella isolates showed resistance to at least one antimicrobial agent (20.2% and 51.5%, respectively), while 19.2% of Salmonella isolates were multidrug-resistant. These results show the relevance of gulls as reservoirs of Campylobacter and Salmonella by maintaining and spreading these bacteria, including resistant and multidrug resistant strains, in the environment. Our results suggest that gulls can serve as sentinel species for antibiotic pressure in the environment.

Differential Distribution of the wlaN and cgtB Genes, Associated with Guillain-Barré Syndrome, in Campylobacter jejuni Isolates from Humans, Broiler Chickens, and Wild Birds.

Campylobacter jejuni causes campylobacteriosis, a bacterial gastroenteritis with high incidence worldwide. Moreover, C. jejuni infection can trigger the polyneuropathic disorder denominated Guillain-Barré syndrome (GBS). The C. jejuni strains that can elicit GBS carry either wlaN or cgtB, coding both genes for a ß-1,3-galactosyltransferase enzyme that is required for the production of sialylated lipooligosaccharide (LOSSIAL). We described a differential prevalence of the genes wlaN and cgtB in C. jejuni isolates from three different ecological niches: humans, broiler chickens, and wild birds. The distribution of both genes, which is similar between broiler chicken and human isolates and distinct when compared to the wild bird isolates, suggests a host-dependent distribution. Moreover, the prevalence of the wlaN and cgtB genes seems to be restricted to some clonal complexes. Gene sequencing identified the presence of new variants of the G- homopolymeric tract within the wlaN gene. Furthermore, we detected two variants of a G rich region within the cgtB gene, suggesting that, similarly to wlaN, the G-tract in the cgtB gene mediates the phase variation control of cgtB expression. Caco-2 cell invasion assays indicate that there is no evident correlation between the production of LOSSIAL and the ability to invade eukaryotic cells.

Contamination of pig carcass with Salmonella enterica serovar Typhimurium monophasic variant 1,4[5],12:i:- originates mainly in live animals.

Pork is considered a major source of Salmonella Typhimurium infection in humans in the EU, including monophasic strains (mST). Widespread distribution of virulent serotypes such as monophasic variants of S. Typhimurium have emerged as a public health threat. Despite the current situation, within the EU there is no mandatory programme for the control of Salmonella at pork production level. In this context, the aims of this study were: to examine the presence of Salmonella in the swine production system from arrival at the slaughterhouse until the end of processing, and investigate the genetic relationship among serovars. A total of 21 pig herds were intensively sampled during processing at the slaughterhouse. ERIC-PCR followed by PFGE were performed among isolates recovered at the different steps in the slaughterhouse to assess their genetic relationship. The results showed a high level of Salmonella pork batch contamination upon arrival at the slaughterhouse (71.4%) and at the end of the slaughtering process (66.7%), with mST the main serovar isolated from both origins (53.1% and 38.2%, respectively). Similarly, this study shows that 14.3% of the strains isolated from carcasses have the same Xbal-PFGE profile as those previously recovered in the slaughterhouse environment, but not in the live animals from that same batch. In conclusion, there is a high level of Salmonella swine batch contamination upon arrival at the slaughterhouse and at the end of the slaughtering process, mST being the most frequently isolated serovar. Moreover, a strong genetic relationship has been observed between strains isolated from the batch on arrival at the slaughterhouse, the processing environment and pork carcass contamination. In this sense, it would be necessary to implement a control programme to reduce the bacterium from pork farms and raise the awareness of biosecurity measures.

Infectious phage particles packaging antibiotic resistance genes found in meat products and chicken feces.

Bacteriophages can package part of their host's genetic material, including antibiotic resistance genes (ARGs), contributing to a rapid dissemination of resistances among bacteria. Phage particles containing ARGs were evaluated in meat, pork, beef and chicken minced meat, and ham and mortadella, purchased in local retailer. Ten ARGs (blaTEM, blaCTX-M-1, blaCTX-M-9, blaOXA-48, blaVIM, qnrA, qnrS, mecA, armA and sul1) were analyzed by qPCR in the phage DNA fraction. The genes were quantified, before and after propagation experiments in Escherichia coli, to evaluate the ability of ARG-carrying phage particles to infect and propagate in a bacterial host. According to microbiological parameters, all samples were acceptable for consumption. ARGs were detected in most of the samples after particle propagation indicating that at least part of the isolated phage particles were infectious, being sul1the most abundant ARG in all the matrices followed by ß-lactamase genes. ARGs were also found in the phage DNA fraction of thirty-seven archive chicken cecal samples, confirming chicken fecal microbiota as an important ARG reservoir and the plausible origin of the particles found in meat. Phages are vehicles for gene transmission in meat that should not be underestimated as a risk factor in the global crisis of antibiotic resistance.

Do humans spread zoonotic enteric bacteria in Antarctica?

Reports of enteric bacteria in Antarctic wildlife have suggested its spread from people to seabirds and seals, but evidence is scarce and fragmentary. We investigated the occurrence of zoonotic enteric bacteria in seabirds across the Antarctic and subantarctic region; for comparison purposes, in addition to seabirds, poultry in a subantarctic island was also sampled. Three findings suggest reverse zoonosis from humans to seabirds: the detection of a zoonotic Salmonella serovar (ser. Enteritidis) and Campylobacter species (e.g. C. jejuni), typical of human infections; the resistance of C. lari isolates to ciprofloxacin and enrofloxacin, antibiotics commonly used in human and veterinary medicine; and most importantly, the presence of C. jejuni genotypes mostly found in humans and domestic animals but rarely or never found in wild birds so far. We also show further spread of zoonotic agents among Antarctic wildlife is facilitated by substantial connectivity among populations of opportunistic seabirds, notably skuas (Stercorarius). Our results highlight the need for even stricter biosecurity measures to limit human impacts in Antarctica.

Population Structure, Antimicrobial Resistance, and Virulence-Associated Genes in Campylobacter jejuni Isolated From Three Ecological Niches: Gastroenteritis Patients, Broilers, and Wild Birds.

Campylobacter jejuni is the causal agent of the food-borne infection with the highest incidence in Europe. Both poultry and wild birds are a major reservoir. To gain insight into the population structure, virulence potential, and antimicrobial resistance (AMR), a collection of 150 isolates from three different ecological niches (broilers, wild birds, and human patients) was studied. Despite the high genetic diversity found, the population structure defined two distinct clusters, one formed mostly by broiler and human isolates and another one by most wild bird isolates. The ST-21 complex exhibits highest prevalence (in humans and broilers), followed by ST-1275 complex (only in wild birds). The ST-48, -45, and -354 complexes were found in all three niches, but represent only 22 out of 150 studied strains. A higher occurrence of AMR and multidrug resistance was detected among broiler and human isolates. Moreover, significant differences were found in the distribution of certain putative virulence genes. Remarkably, many wild bird strains were negative for either cdtA, cdtB, or cdtC from the canonical strain 81-176, whereas all broiler and human strains were positive. These data suggest that the different variants of the cdt genes might be relevant for the efficient colonization of certain hosts by C. jejuni. Our study contributes to the understanding of the role of the diverse Campylobacter reservoirs in the transmission of campylobacteriosis to humans.

Supplementary feeding stations for conservation of vultures could be an important source of monophasic Salmonella typhimurium 1,4,[5],12:i:.

Vultures are nature's most successful scavengers, feeding on the carcasses of dead animals present in the field. Availability of domestic carrion has been unstable due to rapidly changing agro-grazing economies and increasing sanitary regulations that may require burial or burning of livestock carcasses. Thus, several griffon vulture (Gyps fulvus) recoveries are based on European legislation that guarantees the animals' welfare, avoids intense persecution of the vultures and allows the feeding of threatened wildlife in supplementary feeding stations (SFS). However, in recent years, many studies have speculated on the likelihood that avian scavengers may be infected by feeding on pig carcasses at SFS from intensive livestock. In this context, the present study evaluated whether free-living griffon vultures and pig farms share zoonotic Salmonella strains to test the hypothesis that vulture are infected during consumption of carcasses provided at SFS. Here, the occurrence, serotypes and genomic DNA fingerprinting (phage typing and pulsed-field gel electrophoresis) of isolated strains were carried out in griffon vultures and pig farms authorised to provided carcasses at SFS in Castellón province (eastern Spain). The bacteriological analyses revealed that 21.1% of vultures and 14.5% for pig farms samples tested were Salmonella-positive. Monophasic S. typhimurium 1,4,[5],12:i:- was the most frequently isolated serovar. Comparison of Salmonella strains isolated from vultures and pig farms revealed that monophasic S. typhimurium 1,4,[5],12:i:-, S. Derby and S. Rissen strains were highly genetically homogeneous (similar DNA fingerprint). In conclusion, the current study indicates that free-living griffon vultures and pig farms that provide the carcasses at SFS share several zoonotic Salmonella strains. On this basis, and although transmission could be bidirectional, our result seems to corroborate the pig carcasses-to-vulture transmission and cross-infection at SFS. As an immediate Salmonella control strategy in wild avian scavengers, we suggest the implementation of a programme to guarantee that solely pig carcasses from Salmonella-free farms arrive at SFS.

Characterization of Campylobacter jejuni and Campylobacter coli Broiler Isolates by Whole-Genome Sequencing.

Campylobacter has been the most commonly reported cause of bacterial diarrheal disease in humans in the European Union since 2005. Most broiler batches at slaughter are colonized with Campylobacter, and the major source of infection is contaminated poultry meat. The aim of this study was to characterize a selection of Campylobacter jejuni and Campylobacter coli isolates from broilers through whole-genome sequencing (WGS). A total of 16 isolates (C. jejuni = 12 and C. coli = 4) from five broiler farms from Catalonia (northeastern Spain) were analyzed. A phylogenetic analysis based on 8420 single-nucleotide polymorphisms showed two main cluster grouping strains by species. Phenotypic resistances to quinolones (100%), tetracycline (81%), streptomycin (75%), erythromycin (56%), and gentamicin (13%) were found. All the isolates carried the C257T point mutation in the subunit A of the DNA gyrase gene (Thr86Ile) conferring resistance to quinolones, while all the isolates showing resistance to tetracycline carried the tet(O) gene. The genes aph(3')-III and aadE conferring resistance to aminoglycosides were identified in the two isolates (one C. jejuni and one C. coli) resistant to streptomycin and gentamicin. The point mutation A2075G on the 23S rDNA conferring high resistance to macrolides was detected in three C. coli isolates. The CmeABC multidrug efflux pump was also detected, both in C. jejuni and C. coli isolates. All C. jejuni and C. coli isolates were positive for most of the 34 virulence-associated genes studied related to motility, chemotaxis, adhesion, and invasion. Interestingly, the wlaN gene involved in the Guillain-Barré syndrome was found in two isolates. The results underline the power of WGS for investigation of virulence, clonality, and antimicrobial resistance in Campylobacter.

Seabirds (Laridae) as a source of Campylobacter spp., Salmonella spp. and antimicrobial resistance in South Africa.

Zoonotic thermophilic Campylobacter and nontyphoidal Salmonella enterica are a major cause of foodborne human gastroenteritis worldwide. There is little information about reservoirs of these zoonotic agents in Africa. Thus, chicks of kelp gulls (Larus dominicanus, n = 129) and greater crested terns (Thalasseus bergii, n = 100) were studied at five colonies on the Western Cape coast (South Africa) during summer 2013/2014. Campylobacter spp. occurrence was 14.0% (CI95% : 9.9-19.3), with C. jejuni the most frequently isolated species, whilst that of Salmonella was 27.5% (CI95% : 21.9-33.9) overall, with a higher prevalence in gulls (43.0%, CI95% : 34.8-52.4) than terns (7.0%, CI95% : 3.1-14.4). Among the 16 different S. enterica serovars found, Anatum, Enteritidis and Hadar were the most frequent. The same or highly similar pulsed-field gel electrophoresis genotype was found in some Salmonella isolates from seabirds and humans presenting with salmonellosis in Cape Town hospitals. Both Campylobacter and Salmonella isolates exhibited antimicrobial resistance to several agents, including critically important antimicrobials (quinolones, tetracyclines and ß-lactams) and multidrug resistance in Salmonella serovars from kelp gulls. Our results highlight the importance of seabirds as reservoirs of Campylobacter and Salmonella resistant strains and their role in the maintenance and transmission of these bacteria in the environment, with implications for public health.