Salmonella in Retail Food and Wild Birds in Singapore—Prevalence, Antimicrobial Resistance, and Sequence Types

Non-typhoidal salmonellosis is a leading cause of foodborne zoonosis. To better understand the epidemiology of human salmonellosis, this study aimed to determine the prevalence, antimicrobial resistance and sequence types of Salmonella in retail food and wild birds (proximity to humans) in Singapore. We analyzed 21,428 cooked and ready-to-eat food and 1,510 residual faecal samples of wild birds collected during 2010–2015. Thirty-two Salmonella isolates from food and wild birds were subjected to disc diffusion and multi-locus sequence typing (MLST). Salmonella was isolated from 0.08% (17/21,428) of food and 0.99% (15/1510) of wild birds. None of the isolates from wild birds (n = 15) exhibited phenotypic resistance, while the isolates from food (47.1%, 8/17) showed a high prevalence of phenotypic resistance to, at least, one antimicrobial. These findings suggested that the avian Salmonella isolates had been subjected to less antimicrobial selection pressure than those from food samples. MLST revealed specific sequence types found in both food and wild birds. The study can guide future studies with whole-genome analysis on a larger number of isolates from various sectors for public health measures.

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Genetic Diversity of Campylobacter jejuni Isolates from Farm Animals and the Farm Environment

Applied and Environmental Microbiology ◽

10.1128/aem.69.12.7409-7413.2003 ◽

2003 ◽

Vol 69 (12) ◽

pp. 7409-7413 ◽

Cited By ~ 116

Author(s):

F. M. Colles ◽

K. Jones ◽

R. M. Harding ◽

M. C. J. Maiden

Keyword(s):

Genetic Diversity ◽

Campylobacter Jejuni ◽

Human Disease ◽

Clonal Complex ◽

Food Samples ◽

Complex Model ◽

Farm Animals ◽

Significant Genetic Differentiation ◽

Sequence Types ◽

Retail Food

ABSTRACT The genetic diversity of Campylobacter jejuni isolates from farm animals and their environment was investigated by multilocus sequence typing (MLST). A total of 30 genotypes, defined by allelic profiles (assigned to sequence types [STs]), were found in 112 C. jejuni isolates originating in poultry, cattle, sheep, starlings, and slurry. All but two of these genotypes belonged to one of nine C. jejuni clonal complexes previously identified in isolates from human disease and retail food samples and one clonal complex previously associated with an environmental source. There was some evidence for the association of certain clonal complexes with particular farm animals: isolates belonging to the ST-45 complex predominated among poultry isolates but were absent among sheep isolates, while isolates belonging to the ST-61 and ST-42 complexes were predominant among sheep isolates but were absent from the poultry isolates. In contrast, ST-21 complex isolates were distributed among the different isolation sources. Comparison with MLST data from 91 human disease isolates showed small but significant genetic differentiation between the farm and human isolates; however, representatives of six clonal complexes were found in both samples. These data demonstrate that MLST and the clonal complex model can be used to identify and compare the genotypes of C. jejuni isolates from farm animals and the environment with those from retail food and human disease.

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Differences in Neisseria gonorrhoeae population structure and antimicrobial resistance pattern between men who have sex with men and heterosexuals

Epidemiology and Infection ◽

10.1017/s095026881600234x ◽

2016 ◽

Vol 145 (2) ◽

pp. 379-385 ◽

Cited By ~ 7

Author(s):

J. SERRA-PLADEVALL ◽

M. J. BARBERÁ ◽

A. E. CALLARISA ◽

R. BARTOLOMÉ-COMAS ◽

A. ANDREU

Keyword(s):

Population Structure ◽

Antimicrobial Resistance ◽

Neisseria Gonorrhoeae ◽

Antimicrobial Susceptibility ◽

Sexual Practices ◽

Resistance Pattern ◽

High Prevalence ◽

Sex With Men ◽

Resistance Rates ◽

Sequence Types

SUMMARYThis study compared the antimicrobial susceptibility and genotypes of strains of Neisseria gonorrhoeae isolated from men who have sex with men (MSM) and from heterosexuals. One hundred and eleven strains were characterized from 107 patients, comprising 57 strains from 54 heterosexuals and 54 strains from 53 MSM. Antimicrobial resistance rates were higher in strains from heterosexual patients, with resistance to cefixime (P = 0·0159) and ciprofloxacin (P = 0·002) being significantly higher. Typing by N. gonorrhoeae multi-antigen sequence typing (NG-MAST) showed that the most prevalent sequence types (ST) and genogroups (G) respectively were ST2400, ST2992, and ST5793, and G1407, G2992, and G2400. A statistically significant association was observed for MSM and genogroups G2400 (P = 0·0005) and G2992 (P = 0·0488), and G1407 with heterosexuals (P = 0·0002). We conclude that in our region distinct populations of gonococci are circulating among subjects with different sexual practices, with their corresponding transmission patterns. Furthermore, the high prevalence of genotype G2400 in MSM, has not to our knowledge been previously described.

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Molecular Characterization and Antimicrobial Susceptibility of C. jejuni Isolates from Italian Wild Bird Populations

Pathogens ◽

10.3390/pathogens9040304 ◽

2020 ◽

Vol 9 (4) ◽

pp. 304 ◽

Cited By ~ 1

Author(s):

Francesca Marotta ◽

Anna Janowicz ◽

Lisa Di Marcantonio ◽

Claudia Ercole ◽

Guido Di Donato ◽

...

Keyword(s):

Nalidixic Acid ◽

Point Mutations ◽

Bird Species ◽

Acid Resistance ◽

Wild Birds ◽

23S Rrna ◽

The Novel ◽

Phenotypic Resistance ◽

Bird Populations ◽

Sequence Types

Poultry is considered a major reservoir of human campylobacteriosis. It also been reported that not only poultry, but also wild birds, are capable of carrying C. jejuni, thus demonstrating to be a risk of spreading the bacteria in the environment. To gain insight into the population structure and investigate the antimicrobial resistance genotypes and phenotypes, we analyzed a collection of 135 C. jejuni from 15 species of wild birds in Italy. MLST revealed the presence of 41 sequence types (STs) and 13 clonal complexes (CCs). ST-179 complex and the generalist ST-45 complex were the most prevalent. Core genome MLST revealed that C. jejuni from ST-45 complex clustered according to the bird species, unlike the ST-179 complex which featured 3 different species in the same cluster. Overall we found a moderate prevalence of resistance to tetracycline (12.5%), ciprofloxacin and nalidixic acid (10%). The novel ST isolated from one pigeon showed resistance to all the antibiotics tested. The ST-179 complex (33.3%) was identified with significantly higher nalidixic acid resistance relative to other tested STs. Nine AMR genes (tet(O), cmeA, cmeB, cmeC, cmeR, aad, blaOXA-61, blaOXA-184 and erm(B)) and 23S rRNA and gyrA-associated point mutations were also described, indicating a concordance level between genotypic and phenotypic resistance of 23.3%, 23.4% and of 37.5% for streptomycin, tetracycline and quinolones/fluoroquinolones, respectively. We recommend that particular attention should be given to wild birds as key sentinel animals for the ecosystem contamination surveillance.

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Antimicrobial Resistance Genes and Diversity of Clones among Faecal ESBL-Producing Escherichia coli Isolated from Healthy and Sick Dogs Living in Portugal

Antibiotics ◽

10.3390/antibiotics10081013 ◽

2021 ◽

Vol 10 (8) ◽

pp. 1013

Author(s):

Isabel Carvalho ◽

Rita Cunha ◽

Carla Martins ◽

Sandra Martínez-Álvarez ◽

Nadia Safia Chenouf ◽

...

Keyword(s):

Escherichia Coli ◽

Antimicrobial Resistance ◽

Genetic Characteristics ◽

E Coli ◽

Faecal Samples ◽

Antimicrobial Resistance Genes ◽

Healthy Dogs ◽

Positive Isolate ◽

Sequence Types ◽

M 14

The purpose of this study was to analyse the prevalence and genetic characteristics of ESBL and acquired-AmpC (qAmpC)-producing Escherichia coli isolates from healthy and sick dogs in Portugal. Three hundred and sixty-one faecal samples from sick and healthy dogs were seeded on MacConkey agar supplemented with cefotaxime (2 µg/mL) for cefotaxime-resistant (CTXR) E. coli recovery. Antimicrobial susceptibility testing for 15 antibiotics was performed and the ESBL-phenotype of the E. coli isolates was screened. Detection of antimicrobial resistance and virulence genes, and molecular typing of the isolates (phylogroups, multilocus-sequence-typing, and specific-ST131) were performed by PCR (and sequencing when required). CTXRE. coli isolates were obtained in 51/361 faecal samples analysed (14.1%), originating from 36/234 sick dogs and 15/127 healthy dogs. Forty-seven ESBL-producing E. coli isolates were recovered from 32 sick (13.7%) and 15 healthy animals (11.8%). Different variants of blaCTX-M genes were detected among 45/47 ESBL-producers: blaCTX-M-15 (n = 26), blaCTX-M-1 (n = 10), blaCTX-M-32 (n = 3), blaCTX-M-55 (n = 3), blaCTX-M-14 (n = 2), and blaCTX-M-variant (n = 1); one ESBL-positive isolate co-produced CTX-M-15 and CMY-2 enzymes. Moreover, two additional CTXR ESBL-negative E. coli isolates were CMY-2-producers (qAmpC). Ten different sequence types were identified (ST/phylogenetic-group/β-lactamase): ST131/B2/CTX-M-15, ST617/A/CTX-M-55, ST3078/B1/CTX-M-32, ST542/A/CTX-M-14, ST57/D/CTX-M-1, ST12/B2/CTX-M-15, ST6448/B1/CTX-M-15 + CMY-2, ST5766/A/CTX-M-32, ST115/D/CMY-2 and a new-ST/D/CMY-2. Five variants of CTX-M enzymes (CTX-M-15 and CTX-M-1 predominant) and eight different clonal complexes were detected from canine ESBL-producing E. coli isolates. Although at a lower rate, CMY-2 β-lactamase was also found. Dogs remain frequent carriers of ESBL and/or qAmpC-producing E. coli with a potential zoonotic role.

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Most Campylobacter subtypes from sporadic infections can be found in retail poultry products and food animals

Epidemiology and Infection ◽

10.1017/s0950268805005509 ◽

2005 ◽

Vol 134 (4) ◽

pp. 758-767 ◽

Cited By ~ 45

Author(s):

E. M. NIELSEN ◽

V. FUSSING ◽

J. ENGBERG ◽

N. L. NIELSEN ◽

J. NEIMANN

Keyword(s):

Broiler Chickens ◽

Food Samples ◽

Danish Population ◽

Pfge Typing ◽

Poultry Products ◽

Heat Stable ◽

Faecal Samples ◽

Automated Ribotyping ◽

Human Infections ◽

Retail Food

The subtypes of Campylobacter isolates from human infections in two Danish counties were compared to isolates from retail food samples and faecal samples from chickens, pigs and cattle. During a 1-year period, 1285 Campylobacter isolates from these sources were typed by two methods: ‘Penner’ heat-stable serotyping and automated ribotyping (RiboPrinting). C. jejuni was the dominating species, but C. coli was more prevalent among food and chicken isolates (16%) compared to human isolates (4%). In total, 356 different combined sero-ribotypes (subtypes) were found. A large subtype overlap was seen between human isolates and isolates from food (66%), chickens (59%) and cattle (83%). This was verified by PFGE typing of 212 isolates representing selected subtypes. All frequent (n>3) subtypes found in food were also present in humans. Sixty-one per cent of the isolates from domestically acquired infections had subtypes that were also found in food as opposed to 31% of travel-associated infections. The results showed differences in the various Campylobacter populations, e.g. the Danish population as reflected in the domestically acquired infections and the Danish-produced food was more uniform than the isolates originating from outside the country. The study shows that most C. jejuni subtypes found in poultry food samples, broiler chickens, and cattle were represented in the domestically acquired cases, indicating that C. jejuni from these reservoirs are likely sources of human infections in Denmark.

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Occurrence and Antimicrobial Resistance Traits of Escherichia coli from Wild Birds and Rodents in Singapore

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17155606 ◽

2020 ◽

Vol 17 (15) ◽

pp. 5606

Author(s):

Kar Hui Ong ◽

Wei Ching Khor ◽

Jing Yi Quek ◽

Zi Xi Low ◽

Sathish Arivalan ◽

...

Keyword(s):

Escherichia Coli ◽

Antimicrobial Resistance ◽

Wild Birds ◽

Health Concern ◽

Close Monitoring ◽

Drug Resistant ◽

Public Health Concern ◽

E Coli ◽

Faecal Samples ◽

Antimicrobial Resistance Genes

Antimicrobial resistance (AMR) in Escherichia coli (E. coli) poses a public health concern worldwide. Wild birds and rodents, due to their mobility, are potential vehicles for transmission of AMR bacteria to humans. Ninety-six wild birds’ faecal samples and 135 rodents’ droppings samples were collected and analysed in 2017. Forty-six E. coli isolates from wild birds and rodents were subjected to AMR phenotypic and genotypic characterisation. The proportion of E. coli isolates resistant to at least one of the antimicrobials tested from wild birds (80.8%) was significantly higher than that of isolates from rodents (40.0%). The proportion of E. coli isolates resistant to each antimicrobial class for wild birds was 3.8% to 73.1% and that for rodents was 5.0% to 35.0%. Six out of 26 E. coli isolates from wild birds (23.1%) and two out of 20 (10.0%) isolates from rodents were multi-drug resistant (MDR) strains. These MDR E. coli isolates were detected with various antimicrobial resistance genes such as blaTEM-1B and qnrS1 and could be considered as part of the environmental resistome. Findings in this study suggested that wild birds and rodents could play a role in disseminating antimicrobial resistant E. coli, and this underscores the necessity of environment management and close monitoring on AMR bacteria in wild birds and rodents to prevent spreading of resistant organisms to other wildlife animals and humans.

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Wild Micromammals as Bioindicators of Antibiotic Resistance in Ecopathology in Northern Italy

Animals ◽

10.3390/ani10071184 ◽

2020 ◽

Vol 10 (7) ◽

pp. 1184

Author(s):

Giovanna Zanardi ◽

Tiziano Iemmi ◽

Costanza Spadini ◽

Simone Taddei ◽

Sandro Cavirani ◽

...

Keyword(s):

Antibiotic Resistance ◽

Antimicrobial Resistance ◽

Susceptibility Testing ◽

Northern Italy ◽

Drug Resistant ◽

Bacteriological Examination ◽

Bacterial Strains ◽

Faecal Samples ◽

High Prevalence ◽

Microtus Savii

Antimicrobial resistance (AMR) is an increasing threat to human health and an important issue also in the natural environment. For this study, an ecopathological approach was applied to the monitoring of the antimicrobial resistance in the province of Parma, Northern Italy. Fourteen monitoring sites and seventy-four faecal samples from four species of wild micromammals (Apodemus sylvaticus, Microtus savii, Mus domesticus and Suncus etruscus) were collected. Samples were subjected to bacteriological examination and antimicrobial susceptibility testing. Antibiotics belonging to 13 different antibiotic classes were tested. Collected data showed a prevalence of multi-drug resistant (MDR) strains of 55.13% and significant differences in the prevalence of MDR strains among the different micromammal species, while sex, age and anthropization level did not significantly affected MDR strains prevalence. Moreover, a high prevalence of bacterial strains resistant to colistin (95%), gentamicin (87%) and amikacin (83%) was observed. To our knowledge, this is the first report on antibiotic resistance in wild micromammals in the province of Parma.

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Effects of a Direct-Fed Microbial and Feedlot Pen Environmental Change on Phenotypic Resistance among Enterococci Isolated from Beef Cattle Feces

10.20944/preprints202111.0474.v1 ◽

2021 ◽

Author(s):

Sarah A. Murray ◽

Ashlyn C. Holbert ◽

Keri N. Norman ◽

Sara D. Lawhon ◽

Jason E. Sawyer ◽

...

Keyword(s):

Antimicrobial Resistance ◽

Beef Cattle ◽

Resistance Genes ◽

Enterococcus Faecium ◽

Sequence Type ◽

Whole Genome ◽

Fecal Samples ◽

Phenotypic Resistance ◽

The Impact ◽

Sequence Types

In two sequential replicates (n=90 and n=96 feedlot finisher cattle, respectively) we measured the impact of an Enterococcus faecium-based probiotic (DFM) and an altered feedlot pen environment on antimicrobial resistance among fecal enterococci in cattle fed (or, not fed) the macrolide tylosin. Diluted fecal samples were spiral-plated on plain and antibiotic-supplemented m-Enterococcus agar. In the first replicate, tylosin significantly (p&lt;0.05) increased the relative quantity of erythromycin-resistant enterococci. This effect was diminished in cattle fed the DFM in conjunction with tylosin. A similar observed effect was not statistically significant (P &gt; 0.05) in the second replicate. Isolates were speciated and resistance phenotypes were obtained for E. faecium and E. hirae. E. faecium isolates were whole-genome sequenced, which yielded sequence types (ST), resistance genes and phylogeny. Samples of the DFM were sequenced and found to contain E. faecium ST296, which was not present on Day 0 of either replicate. This DFM sequence type was found in fecal samples after Day 0, the majority of which were isolated from cattle in one of the DFM-fed pens. Increased prevalence of ST296 occurred with a concomitant decrease in ST240; of importance, the latter typically harbored both ermB and tet(M) genes.

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Antimicrobial resistance, class 1 integrons, and horizontal transfer in Salmonella isolated from retail food in Henan, China

The Journal of Infection in Developing Countries ◽

10.3855/jidc.4190 ◽

2014 ◽

Vol 8 (06) ◽

pp. 705-711 ◽

Cited By ~ 10

Author(s):

Tao Yu ◽

Xiaojie Jiang ◽

Qiaohong Zhou ◽

Junmei Wu ◽

Zhenbin Wu

Keyword(s):

Antimicrobial Resistance ◽

Horizontal Transfer ◽

Food Samples ◽

Foodborne Diseases ◽

Mobile Dna ◽

Class 1 Integrons ◽

Class 1 ◽

Dna Elements ◽

Cooked Meat ◽

Retail Food

Introduction: Salmonellosis remains one of the most frequently occurring foodborne diseases worldwide, especially in developing countries. The increasing prevalence of multidrug resistance among Salmonella isolates from food has been an emerging problem in China. Methodology: In this study, a total of 638 food samples including raw meat, seafood, vegetables, and cooked meat were collected in Henan province of China between July 2007 and August 2008 to determine the prevalence of Salmonella. These isolates were subjected to serotyping, antimicrobial susceptibility, presence of class 1 integrons, and horizontal transfer of integrons. Results: The overall percentage of Salmonella prevalence was 9.7% (n = 62). Among these isolates, S. Anatum and S. Senftenberg were most common, and high rates of antimicrobial resistance were observed to sulfamethoxazole (90.3%), trimethoprim/sulfamethoxazole (87.1%), streptomycin (29.0%), and ciprofloxacin (25.8%). Class 1 integrons were detected in 16.1% of these isolates, and contained gene cassettes dfrA12-aadA2, dfrA1-aadA1, and dfrA1. Three Salmonella isolates could transfer their integrons and resistance genes to Escherichia coli by conjugation. Conclusions: Our findings indicate that the mobile DNA elements could play an important role in the dissemination of resistance determinants among those Salmonella isolates.

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Inhibition of Bacterial Biofilm Formation by Phytotherapeutics with Focus on Overcoming Antimicrobial Resistance

Current Pharmaceutical Design ◽

10.2174/1381612826666200212121710 ◽

2020 ◽

Vol 26 (24) ◽

pp. 2807-2816 ◽

Cited By ~ 1

Author(s):

Yun Su Jang ◽

Tímea Mosolygó

Keyword(s):

Antimicrobial Resistance ◽

Biofilm Formation ◽

Antimicrobial Agents ◽

Bacterial Biofilm ◽

Experimental Investigations ◽

Resistant Bacteria ◽

Salmonella Spp ◽

Food Borne ◽

High Prevalence ◽

Scientific Attention

: Bacteria within biofilms are more resistant to antibiotics and chemical agents than planktonic bacteria in suspension. Treatment of biofilm-associated infections inevitably involves high dosages and prolonged courses of antimicrobial agents; therefore, there is a potential risk of the development of antimicrobial resistance (AMR). Due to the high prevalence of AMR and its association with biofilm formation, investigation of more effective anti-biofilm agents is required. : From ancient times, herbs and spices have been used to preserve foods, and their antimicrobial, anti-biofilm and anti-quorum sensing properties are well known. Moreover, phytochemicals exert their anti-biofilm properties at sub-inhibitory concentrations without providing the opportunity for the emergence of resistant bacteria or harming the host microbiota. : With increasing scientific attention to natural phytotherapeutic agents, numerous experimental investigations have been conducted in recent years. The present paper aims to review the articles published in the last decade in order to summarize a) our current understanding of AMR in correlation with biofilm formation and b) the evidence of phytotherapeutic agents against bacterial biofilms and their mechanisms of action. The main focus has been put on herbal anti-biofilm compounds tested to date in association with Staphylococcus aureus, Pseudomonas aeruginosa and food-borne pathogens (Salmonella spp., Campylobacter spp., Listeria monocytogenes and Escherichia coli).

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