Detection of Salmonella in Finishing Pigs on Farm and at Slaughter in Piedmont,Italy

Salmonella is one of the most common causes of human gastroenteritis often associated with pork consumption. The aims of this cross‐sectional study were to collect preliminary data on the presence of Salmonella enterica in pigs in Piedmont (Italy), through sampling on farm and at slaughter and to gather pilot data on serotypes and phagetypes present in the sampled area and distribution of anti‐microbial resistance among isolated strains. Salmonella was detected through culture and identified with Salmonella spp. and Salmonella Typhimurium PCR; positive samples were serotyped, phagetyped and tested for antibiotic susceptibility. Positive samples (from 9% of faeces up to 29% of tonsils) were found in 64% of the herds. Salmonella spp. was retrieved also from scalding water. Most of the isolates were Salmonella Derby, Salmonella Typhimurium and Salmonella 4,5,12:i:‐. The results of Salmonella Typhimurium specific PCR suggested that Salmonella 4,5,12:i:‐ might be unrecognized by serotyping. Anti‐microbial resistance was recorded in 75–100% of the isolates. Phagetyping allowed the identification of DT104B and DT46A strains. These results set the bases for further research studies that would aim to estimate the real herd prevalence in Piedmont and the diffusion of serotypes and anti‐microbial resistant strains within the same region.     

Serotype identification and antimicrobial resistance profiles of <Emphasis Type="Italic">Salmonella</Emphasis> spp. isolated from chicken carcasses

In this study, 32 Salmonella strains isolated from 400 chicken carcasses were serotyped, and antibiotic resistance profiles were detected against 12 selected antimicrobial agents using disc diffusion method. Thirty-two isolates were identified as follows; 22 (68.7%) Salmonella Enteritidis, five (15.6%) Salmonella Virchow, three (9.3%) Salmonella Typhimurium and two (6.2%) Salmonella Hadar. In all Salmonella isolates, antibiotic resistance were detected. Out of 32 Salmonella strains, 22 (68.75%) displayed multi-drug resistance. Thirty-two (100.0%) of the isolates were found to be resistant to penicillin G, 20 (62.5%) to nalidixic acid, four (12.5%) to cephalothin, two (6.2%) to streptomycin and two (6.2%) to tetracycline. Fifteen (68.1%) Salmonella Enteritidis, one (33.3%) Salmonella Typhimurium, two (100.0%) Salmonella Hadar and two (40.0%) Salmonella Virchow were shown to be resistant to nalidixic acid. Cephalothin resistance was detected in 9.0%, 33.3%, and 20.0% for Salmonella Enteritidis, Salmonella Typhimurium and Salmonella Virchow, respectively. The results indicate that Salmonella recovered from chicken carcasses were resistant to multiple antimicrobials and that resistance among these isolates varies by serotype. Also, this emerged as a significant public health problem.     

Phenotypic and Genotypic Characterization of Salmonella enterica in Captive Wildlife and Exotic Animal Species in Ohio,USA

The purpose of this study was to investigate the occurrence, antimicrobial resistance patterns, phenotypic and genotypic relatedness of Salmonella enterica recovered from captive wildlife host species and in the environment in Ohio, USA. A total of 319 samples including faecal (n = 225), feed (n = 38) and environmental (n = 56) were collected from 32 different wild and exotic animal species in captivity and their environment in Ohio. Salmonellae were isolated using conventional culture methods and tested for antimicrobial susceptibility with the Kirby–Bauer disc diffusion method. Salmonella isolates were serotyped, and genotyping was performed using the pulsed‐field gel electrophoresis (PFGE). Salmonella was detected in 56 of 225 (24.9%) faecal samples; six of 56 (10.7%) environmental samples and six of 38 (15.8%) feed samples. Salmonella was more commonly isolated in faecal samples from giraffes (78.2%; 36/46), cranes (75%; 3/4) and raccoons (75%; 3/4). Salmonella enterica serotypes of known public health significance including S. Typhimurium (64.3%), S. Newport (32.1%) and S. Heidelberg (5.3%) were identified. While the majority of the Salmonella isolates were pan‐susceptible (88.2%; 60 of 68), multidrug‐resistant strains including penta‐resistant type, AmStTeKmGm (8.8%; six of 68) were detected. Genotypic diversity was found among S. Typhimurium isolates. The identification of clonally related Salmonella isolates from environment and faeces suggests that indirect transmission of Salmonella among hosts via environmental contamination is an important concern to workers, visitors and other wildlife. Results of this study show the diversity of Salmonella serovars and public health implications of human exposure from wildlife reservoirs.     

Salmonella in breeding pigs: Shedding pattern,transmission of infection and the role of environmental contamination in Irish commercial farrow‐to‐finish herds

This study aimed to provide new insights into the epidemiology of Salmonella in pig production, focusing on potential shedding patterns in breeding pigs throughout a full production cycle and the risk of transmission of infection from the sow to her offspring. A longitudinal study was conducted on five farrow‐to‐finish commercial pig farms. In each herd, shedding of Salmonella in faeces was monitored in breeders through service, gestation and lactation. Swabs of the farrowing room floor and pools of faeces from piglets were collected on two occasions during lactation. Environmental pen swabs were also taken in the weaning and finisher houses. Salmonella isolates were serotyped, tested for antimicrobial resistance (AMR) and typed by Multiple‐Locus Variable number tandem repeat Analysis (MLVA). Shedding by breeding pigs was low in all stages of the production cycle; 5% of sows shed at service, the production stage with highest risk of shedding (p < .01), 1.6% shed during gestation and 2.5% after farrowing. Salmonella was detected in 4% of piglet faecal pools in the second week post‐farrowing and 5% in the fourth week. Serotyping and AMR profiles of Salmonella isolates revealed that strains in sows and gilts were mostly different from strains isolated in weaner and finisher facilities. MLVA typing confirmed that the source of infection in piglets was in most instances the contaminated environment rather than their dam. Based on the typing results, it appears that sows do not pose a major risk in the maintenance and transmission of Salmonella to their progeny but instead the contaminated pen environment is more significant in the perpetuation of the organism on farm.     

Epidemiology of Subclinical Salmonellosis in Wild Birds from an Area of High Prevalence of Pig Salmonellosis: Phenotypic and Genetic Profiles of Salmonella Isolates

The epidemiology of subclinical salmonellosis in wild birds in a region of high Salmonella prevalence in pigs was studied. Three hundred and seventy‐nine faecal samples from 921 birds trapped in 31 locations nearby pig premises, and 431 samples from 581 birds of 10 natural settings far from pig farms were analysed for the presence of Salmonella spp. Positive samples were serotyped and analysed for antimicrobial resistance (AR). Phage typing and pulsed‐field gel electrophoresis (PFGE) on Salmonella Typhimurium isolates were also carried out. The overall proportion of Salmonella‐positive samples was 1.85% (95% CI = 0.93, 2.77). Salmonella isolation was positively associated with samples collected from birds in the proximity of a pig operation (OR = 16.5; 95% CI = 5.17, 52.65), and from non‐migratory (or short‐distance migration) birds (OR = 7.6; 95% CI = 1.20, 48.04) and negatively related to mostly granivorous birds (OR = 0.4; 95% CI = 0.15, 1.13). Salmonella Typhimurium was the most prevalent serotype and four different XbaI PFGE patterns were observed that matched the four phage types identified (U310, U311, DT164 and DT56). Only 20% of the strains showed multi‐AR. In three farms, a high degree of homogeneity among isolates from different birds was observed. These findings suggested that pig farms may act as amplifiers of this infection among wild birds, and the degree of bird density may have much to do on this transmission. Some of the Salmonella serotypes isolated from bird faeces were of potential zoonotic transmission and associated with AR. Monitoring salmonellosis in wild bird is advised.     

Reptile‐Associated Salmonellosis in Minnesota, 1996–2011

Reptile‐associated salmonellosis (RAS) occurs when Salmonella is transmitted from a reptile to a human. This study describes the epidemiology of RAS in Minnesota during 1996–2011. All Minnesotans with confirmed Salmonella infections are reported to the Minnesota Department of Health (MDH). Case patients are interviewed about illness characteristics and risk factors, including foods eaten, drinking and recreational water exposures, contact with ill people, and animal contact. Willing RAS case patients can submit stool from the reptile for culture. Serotype and pulsed‐field gel electrophoresis (PFGE) subtype of Salmonella isolates from reptiles and case patients are compared. Of 8389 sporadic (not associated with an outbreak) non‐typhoidal salmonellosis case patients in Minnesotans during 1996–2011, 290 (3.5%) reported reptile exposure. The median age of case patients with reptile exposure was 11 years, 31% were under the age of 5 years and 67% were under the age of 20 years; 50% were female. The median illness duration was 8 days; 23% required hospitalization. The most commonly reported reptile exposures were lizard (47%), snake (20%), turtle (19%) and a combination of reptile types (14%). Eighty‐four per cent of isolates from case patients who reported reptile exposure were Salmonella enterica subspecies I. The three most common serotypes were Typhimurium (15%), Enteritidis (7%) and subspecies IV serotypes (7%). Of 60 reptiles testing positive for Salmonella, 36 (60%) yielded the same Salmonella serotype as the human isolate. Twenty‐six of 27 reptile isolates that were subtyped by PFGE were indistinguishable from the human isolate. Of these, 88% were subspecies I; the most common serotypes were Enteritidis (12%), Typhimurium (8%), and Bareilly (8%). RAS accounts for approximately 3.5% of salmonellosis cases in Minnesota, primarily affecting children. The majority of isolates from case patients and reptiles belonged to Salmonella subspecies I, suggesting that reptiles are a source of human infection with serotypes not traditionally considered to be reptile‐associated.     

Molecular typing of monophasic Salmonella 4,[5]:i:- strains isolated in Belgium (2008–2011)

To assess the distribution of Salmonella 4,[5]:i:- subtypes in the Belgian food chain and compare it to the subtypes associated with human infections, a molecular assessment was initiated. Two hundred fifty-three Salmonella isolates serotyped as 4,[5]:i:- during the period 2008–2011 in Belgium and originating from animal productions, food or human clinical samples were analysed by a specific duplex PCR. One hundred ninety-four isolates (76.7%) fit the profile of a S. Typhimurium monophasic variant as defined by the European Food Safety Authority. The other isolates possessed but did not express the phase II flagellin gene (23.3%). Multiple Locus Variable Number of Tandem Repeats Analysis (MLVA) revealed many but closely related profiles in the fljB-negative S. Typhimurium monophasic variant isolates. Some MLVA types were associated with both human and animal isolates but no unique source of human contamination could be demonstrated.     

Characterization of integron mediated antimicrobial resistance in Salmonella isolated from diseased swine

Forty-two Salmonella isolates obtained from diseased swine were genetically characterized for the presence of specific antimicrobial resistance mechanisms. Twenty of these isolates were characterized as S. Typhimurium DT104 strains. Pulsed-field gel electrophoresis was used to determine genetic relatedness and revealed 20 distinct genetic patterns among the 42 isolates. However, all DT104 isolates fell within 2 closely related genetic clusters. Other Salmonella isolates were genetically grouped together according to serotype. All DT104 isolates displayed the penta-resistance phenotype to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline. Resistance to sulfamethoxazole, tetracycline, streptomycin, kanamycin, and ampicillin was most common among the non-DT104 Salmonella isolates. All DT104 strains contained 2 chromosomal integrons of 1000 and 1200 base pairs. The DNA sequencing revealed that the 2 integrons contained genes encoding a resistance to streptomycin and ampicillin, respectively. None of the non-DT104 strains showed the same pattern, although several strains possessed integrons of 1000 base pairs or larger. However, the majority of non-DT104 Salmonella strains did not possess any integrons. Two Salmonella isolates displayed tolerance to the organic solvent cyclohexane, indicating the possibility that they are overexpressing chromosomal regulatory genes marA or soxS or the associated multidrug efflux pump, acrAB. This research suggests that integrons contribute to antimicrobial resistance among specific swine Salmonella serotypes; however, they are not as widely disseminated among non-Typhimurium swine Salmonella serotypes as previously thought.     

Phage and MLVA Typing of Salmonella Enteritidis Isolated from Layers and Humans in Belgium from 2000–2010, A Period in which Vaccination of Laying Hens was Introduced

The aim of the study was to characterize isolates of Salmonella enterica serovar Enteritidis (S. Enteritidis) obtained from humans and layer farms in Belgium collected during 2000–2010. Three periods were compared, namely (i) before implementation of vaccination (2000–2004), (ii) during voluntary vaccination (2005–2006) and (iii) during implementation of the national control program (NCP) for Salmonella including mandatory vaccination against S. Enteritidis (2007–2010). The characteristics compared across time periods were distributions of phage type and multiple‐locus variable number tandem‐repeat assay (MLVA). While PT4 and PT21 were predominantly isolated in Belgium in layers and humans before 2007, a significant reduction of those PTs was observed in both populations in the period 2007–2010. The relative proportion of PT4b, PT21c and PT6c was found to have increased considerably in the layer population since 2007. In the human population, PT8, PT1 and the group of ‘other’ PTs were more frequently isolated compared to the previous periods. When comparing the proportion of the predominant MLVA types Q2 and U2, no significant difference was found between the layer and human population in the three periods and between periods within each category (layer and human). A significant difference in isolate distribution among MLVA clusters I and II was found between human and layer isolates recovered during Period 3 and in the human population between Period 1 and 3. Results suggest that the association between S. Enteritidis in layers and the occurrence of the pathogen in humans changed since implementation of the NCP in 2007.     

Serotypes of Salmonella Isolated from Faeces of Patients with Acute Diarrhoea in Gwangju Area,Korea, During 2000–2009

The purpose of this study was to determine the changing pattern of Salmonella serotypes causing acute diarrhoea in humans in Gwangju area, Korea, during 2000–2009. A total of 596 Salmonella isolated from culture of 29 896 faecal samples of patients with acute diarrhoea were included in this study. Faecal samples were collected from local hospitals and clinics in Gwangju area during January 2000–December 2009. The mean annual frequency of isolates for the 10 years was 2.0% (range, 0.9–6.0). The isolates were serologically classified into 43 different serotypes. The 10 most common serotypes were Salmonella Enteritidis (47.9%), S. Typhimurium (20.4%), S. Braenderup (3.2%), S. Montevideo (2.9%), S. Paratyphi B (2.9%), S. London (2.3%), S. Bardo (1.7%), S. Virchow (1.7%), S. Infantis (1.5%) and S. Typhi (1.5%), accounting for 86% of all the isolates. Temporal variations were observed in the distribution of different Salmonella serotypes over the years, and only S. Enteritidis and S. Typhimurium were persistent throughout the study period. Although age specificity varied with serotypes, Salmonella was isolated most frequently from children below 5 years of age (179/596, 30.0%). A seasonal trend was apparent, and the highest rates were found in the summer months. This is the first report of the annual frequency of isolation of Salmonella serotypes, and seasonal and age‐specific patterns of salmonellosis in humans in Gwangju area, Korea, over a decade‐long period.     

Distribution of Salmonella Serovars and Antimicrobial Susceptibility from Poultry and Swine Farms in Central Vietnam

This study was conducted to estimate the prevalence of Salmonella spp. and their antimicrobial susceptibilities on poultry and swine farms, sampled in 2 regions in Central Vietnam. A total of 67 poultry farms and 46 swine farms were sampled in a period of 5 months (from September 2012 to January 2013). Salmonella spp. was prevalent in 46.3% and 71.7% of poultry and swine farms, respectively. Altogether, 99 non‐typhoidal Salmonella were isolated and the most common serovars were Salmonella Weltevreden (19%), followed by Salmonella Typhimurium (12%) and Salmonella 4,[5],12:i:‐ (11%). Overall, 71 of 99 (72%) Salmonella isolates were resistant to at least one of the 14 antimicrobial agents tested. Both in poultry and swine farms, high levels of resistance were observed for ampicillin, chloramphenicol, ciprofloxacin, sulphamethoxazole and tetracycline. The presence of Salmonella isolates from poultry and swine farms which were resistant to different classes of antimicrobials suggests that alternative control measures to antimicrobials should be implemented. Moreover, an effective policy should be promoted to encourage a prudent use of these agents in animal farming in Vietnam.     

Prevalence,Characterization and Antibiotic Resistance of Salmonella Isolates in Large Corvid Species of Europe and North America Between 2010 and 2013

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.     

A case–case study comparing the individual risk factors and symptomatology of Salmonella Heidelberg and Salmonella Typhimurium in Ontario in 2015, following implementation of the Ontario Investigation Tools

Salmonella Heidelberg and Salmonella Typhimurium are among the most common serotypes responsible for human salmonellosis in Ontario. Introduction of the Ontario Investigation Tools (OIT) in 2014 allowed for standardized case investigation and reporting. This study compared the risk factors and symptomatology for sporadic S. Heidelberg and S. Typhimurium cases reported in Ontario in 2015, following implementation of the OIT. Multilevel logistic regression models were applied to assess associations between serotype and individual‐level demographic characteristics, exposures and symptoms for sporadic confirmed cases of S. Heidelberg and S. Typhimurium in Ontario in 2015. There were 476 sporadic cases of S. Typhimurium (n = 278) and S. Heidelberg (n = 198) reported in Ontario in 2015. There were significant associations between the odds of the isolate from a case being one of these serotypes, and travel, consumption of sprouts (any type), contact with reptiles and development of malaise, fever or bloody diarrhoea. The S. Typhimurium and S. Heidelberg cases differed in both symptom presentation and risk factors for illness. Case–case comparisons of Salmonella serotypes have some advantages over case–control studies in that these are less susceptible to selection and recall bias while allowing for rapid comparison of cases to identify potential high‐risk exposures that are unique to one of the serotypes when compared to the other. Comparing cases of two different Salmonella serotypes can help to highlight risk factors that may be uniquely associated with one serotype, or more strongly associated with one serotype compared to another. This information may be useful for understanding relative source attribution between common serotypes of Salmonella.     

Characterization of Salmonella enterica serovar Typhimurium and Salmonella enterica serovar 4,[5],12:i:- isolates from pigs presenting with diarrhea in Korea

Between 2011 and 2012, a total of 896 pig fecal samples were collected from nine provinces in Korea, and 50 salmonella enterica susp. enterica serovar Typhimurium (S. Typhimurium) was isolated. The characteristics of the 50 strains were analyzed, and 4 strains were identified as Salmonella enterica subsp. enterica serovar 4,[5],12:i:-. Salmonella 4,[5],12:i:- could not be distinguished from S. Typhimurium through phage typing, antimicrobial resistance testing or multiple-locus variable-number tandem repeat analysis (MLVA). However, among the four Salmonella 4,[5],12:i:- strains, one (KVCC-BA1400078) was identified as a Salmonella 4,[5],12:i:- clone isolated from humans in the United States, and another (KVCC-BA1400080) was identified as DT193, which has been primarily isolated from humans and animals in European countries. The presence of Salmonella 4,[5],12:i:- in Korea poses a significant threat of horizontal transfer between pigs and humans.     

Multistate Outbreak of Human Salmonella Typhimurium Infections Linked to Pet Hedgehogs – United States, 2011–2013

Zoonotic Salmonella infections cause approximately 130 000 illnesses annually in the United States. Of 72.9 million US households owning at least one pet, five million own small mammals; 3000 hedgehogs were documented by USDA in USDA‐licensed breeding facilities and pet stores in 2012. State health department collaborators and PulseNet, the national bacterial subtyping network, identified human infections of a Salmonella Typhimurium outbreak strain, which were investigated by CDC, USDA‐APHIS and state public and animal health officials. A case was defined as an illness in a person infected with the outbreak strain identified between 1 December 2011 and 3 June 2013. Investigators collected information on patient exposures, cultured animal and environmental specimens for Salmonella, and conducted traceback investigations of USDA‐licensed hedgehog facilities. There were 26 cases in 12 states. Illness onset dates ranged from 26 December 2011 to 8 April 2013. The median patient age was 15 years (range = <1–91 years); 58% were female. Among 23 persons with available information, 8 (35%) were hospitalized and one outbreak strain‐associated death was reported. Of 25 patients with available information, 20 (80%) reported pet hedgehog contact in the week before illness onset. The outbreak strain was isolated from animal and environmental samples collected from three ill persons’ homes in three states. Hedgehogs were purchased in geographically distant states from USDA‐licensed breeders (10/17, 59%); a USDA‐licensed pet store (1/17, 6%); unlicensed or unknown status breeders (3/17, 18%); and private individuals (3/17, 18%). Traceback investigations of USDA‐licensed facilities did not reveal a single source of infection. Public and animal health collaboration linked pet hedgehog contact to human infections of Salmonella Typhimurium, highlighting the importance of a One Health investigative approach to zoonotic salmonellosis outbreaks. More efforts are needed to increase awareness among multiple stakeholders on the risk of illness associated with pet hedgehogs.     

Antimicrobial Resistance Profiles and Diversity in Salmonella from Humans and Cattle, 2004–2011

Analysis of long‐term anti‐microbial resistance (AMR) data is useful to understand source and transmission dynamics of AMR. We analysed 5124 human clinical isolates from Washington State Department of Health, 391 cattle clinical isolates from the Washington Animal Disease Diagnostic Laboratory and 1864 non‐clinical isolates from foodborne disease research on dairies in the Pacific Northwest. Isolates were assigned profiles based on phenotypic resistance to 11 anti‐microbials belonging to eight classes. Salmonella Typhimurium (ST), Salmonella Newport (SN) and Salmonella Montevideo (SM) were the most common serovars in both humans and cattle. Multinomial logistic regression showed ST and SN from cattle had greater probability of resistance to multiple classes of anti‐microbials than ST and SN from humans (P < 0.0001). While these findings could be consistent with the belief that cattle are a source of resistant ST and SN for people, occurrence of profiles unique to cattle and not observed in temporally related human isolates indicates these profiles are circulating in cattle only. We used various measures to assess AMR diversity, conditional on the weighting of rare versus abundant profiles. AMR profile richness was greater in the common serovars from humans, although both source data sets were dominated by relatively few profiles. The greater profile richness in human Salmonella may be due to greater diversity of sources entering the human population compared to cattle or due to continuous evolution in the human environment. Also, AMR diversity was greater in clinical compared to non‐clinical cattle Salmonella, and this could be due to anti‐microbial selection pressure in diseased cattle that received treatment. The use of bootstrapping techniques showed that although there were shared profiles between humans and cattle, the expected and observed number of profiles was different, suggesting Salmonella and associated resistance from humans and cattle may not be wholly derived from a common population.     

Prevalence and characterization of multidrug resistance and variant Salmonella genomic island 1 in Salmonella isolates from cattle,poultry and humans in Iran

Salmonella enterica is a common food‐borne pathogen with occasional multidrug resistance (MDR). Salmonella genomic island (SGI1) is a horizontally transmissible genomic island, containing an MDR gene cluster. All Salmonella serotypes are public health concern, although there is an additional concern associated with those that harbour SGI1. In Iran, there are no data on the presence of SGI1 variants in Salmonella isolates. The present study was conducted to identify MDR‐ and SGI1‐carrying Salmonella strains isolated from various sources and to compare their genetic relatedness between human and animal sources. In total, 242 Salmonella isolates collected from chicken, cattle, and humans from 2008 through 2014 were studied. The isolates were tested for resistance to 14 antimicrobials via the disc diffusion method. They were also tested for the presence of SGI1 variants via PCR, and genetic relatedness was evaluated based on pulsed‐field gel electrophoresis (PFGE). Resistance to at least one antimicrobial agent was observed in 132 (54%) Salmonella isolates (n = 242), while more than 40% of the isolates showed MDR. Based on PCR analysis, eight variants of SGI1, including SGI1, SGI1‐B, SGI1‐C, SGI1‐D, SGI1‐F, SGI1‐I, SGI1‐J and SGI1‐O, were found in both human and animal isolates. Statistical analysis revealed no significant difference in the prevalence of SGI1 variants between human and animal isolates (p > 0.05). Macrorestriction PFGE analysis of the isolates with the same SGI1 variant and resistance patterns revealed genetic relatedness ranging from 70% to 100% among human and animal isolates. According to our review, this is the first documentation of SGI1 in Salmonella isolates in Iran. The presence of similar SGI1 variants in both humans and animals, along with their related PFGE patterns, suggests that food‐producing animals may be a source of MDR Salmonella isolates in Iran.     

Wild Bonelli’s eagles (Aquila fasciata) as carrier of antimicrobial resistant Salmonella and Campylobacter in Eastern Spain

Wild birds have repeatedly been found to be involved in the dissemination of enteric bacterial pathogens in the environment. The aim of this study was to determine the occurrence of Salmonella and Campylobacter as well as the antimicrobial resistance in wild Bonelli’s eagles nestlings in Eastern Spain. In addition, we compared the efficiency of two sampling methods (fresh faecal samples from nest and cloacal swabs from nestlings) for detection of both bacteria. A total of 28 nests with 45 nestlings were analysed. In the nest, Salmonella occurrence was 61 ± 9.2%, while Campylobacter occurrence was 11 ± 5.8% (p < 0.05). In the nestlings, Salmonella occurrence was 36 ± 7.1%, while Campylobacter occurrence was 11 ± 4.7% (p < 0.05). Eight Salmonella serovars were identified, and the most frequently isolated were S. Enteritidis, S. Typhimurium, S. Houston, and S. Cerro. Only one Campylobacter species was identified (C. jejuni). Regarding antimicrobial resistance, the Salmonella strains isolated were found to be most frequently resistant to ampicillin and to tigecycline; however, the sole Campylobacter strain recovered was multidrug resistant. In conclusion, this study demonstrated that wild Bonelli’s eagles nestlings are greater carriers of Salmonella than of Campylobacter. Both Salmonella and Campylobacter isolates exhibited antimicrobial resistance. In addition, faecal samples from nests were most reliable for Salmonella detection, while cloacal swab from nestlings were most reliable for Campylobacter detection.     

Prevalence and Spatial Distribution of Salmonella Infections in the Pennsylvania Raccoon (Procyon lotor)

A study was conducted to determine the prevalence and spatial distribution of Salmonella infection in Pennsylvania raccoons (Procyon lotor), common wildlife mammals known to occupy overlapping habitats with humans and domestic food animals. The Pennsylvania Game Commission provided a total of 371 raccoon intestinal samples from trapped and road‐killed raccoons collected between May and November 2011. Salmonella was isolated from the faeces of 56 (15.1%) of 371 raccoons in 35 (54%) of 65 counties across Pennsylvania. The five most frequently isolated serotypes were Newport (28.6%), Enteritidis (19.6%), Typhimurium (10.7%), Braenderup (8.9%) and Bareilly (7.1%). Pulsed‐field gel electrophoresis (PFGE) analysis of the Salmonella isolates and subsequent comparison to the Pennsylvania Department of Health human Salmonella PFGE database revealed 16 different pulsetypes in Salmonella isolates recovered from raccoons that were indistinguishable from pulsetypes of Salmonella collected from clinically ill humans during the study period. The pulsetypes of seven raccoon Salmonella isolates matched those of 56 human Salmonella isolates by month and geographical region of sample collection. Results from Clustered Regularly Interspaced Short Palindromic Repeats and Multi‐Virulence Locus Sequence Typing (CRISPR‐MVLST) analysis corroborated the PFGE and serotyping data. The findings of this study show that several PFGE pulsetypes of Salmonella were shared between humans and raccoons in Pennsylvania, indicating that raccoons and humans might share the same source of Salmonella.     

Infectivity and persistence of an outbreak strain of Salmonella enterica serotype Typhimurium DT160 for house sparrows (Passer domesticus) in New Zealand

AIM: To examine the infective dose, incubation period and disease progression of an isolate of Salmonella enterica serotype Typhimurium definitive type 160 (DT160) originating from a naturally-infected house sparrow (Passer domesticus) during an outbreak of the disease in New Zealand.

METHODS: Thirty-six house sparrows captured from the wild and free of Salmonella spp were divided into six groups of six birds, housed individually, and inoculated orally with phosphate buffered saline (PBS) or 10¹, 10², 10³, 10⁵, 2 × 10⁸ colony forming units (cfu) of the outbreak strain of S. Typhimurium DT160. The birds were observed for 10 days for clinical signs and/or mortality, and faecal samples were collected to determine excretion of S. Typhimurium. The birds were eutha- nised 11 days post-inoculation (p.i.) and a wide range of tissue samples were collected for histopathological examination, and culture and typing of Salmonella spp. Macro-restriction profiling by pulsed-field gel electrophoresis (PFGE) using XbaI was performed for the epidemiological typing of S. Typhimurium DT160 isolates.

RESULTS: Mortality in house sparrows inoculated with S. Typhimurium DT160 was dose-dependent, and 2/6 birds inoculated with ¹⁰⁵ cfu and all six birds inoculated with 2 × 10⁸ cfu died during the study. Infected sparrows displayed few clinical signs, apart from diarrhoea and/or polyuria, fluffed plumage, and sitting on the floor of the cage. Faecal excretion of DT160 occurred briefly in two birds inoculated with 10² cfu and four birds inoculated with 10³ cfu, on most days in five birds inoculated with 10⁵ cfu, and continuously in six birds inoculated with 2 × 10⁸ cfu. DT160 was isolated from the livers of three birds which received 10³ cfu, five birds dosed with 10⁵ cfu, and all six birds given 2 × 10⁸ cfu. Following necropsy, histopathological lesions similar to those seen in the natural disease were observed in the liver or spleen of three birds which received 10³ cfu, and all birds dosed with ≥10⁵ cfu.

CONCLUSION: The results indicate that an isolate of S. Typhimurium DT60 originating from house sparrows in New Zealand is pathogenic to these birds and that the response is dose- dependent. The persistence and excretion of the pathogen may last for at least 10 days. This confirms that sparrows infected with DT160 could be a source of infection to humans and other in-contact animals.