Frequent human‐poultry interactions and low prevalence of Salmonella in backyard chicken flocks in Massachusetts

The backyard chicken (BYC) movement in the USA has increased human contact with poultry and subsequently, human contact with the pathogen Salmonella. However, to date, there have been few studies assessing prevalence of Salmonella in backyard flocks, despite the known public health risk this zoonotic bacterium poses. The objective of this study was to characterize human‐BYC interactions and assess the prevalence of Salmonella among BYC flocks. We interviewed 50 BYC owners using a structured questionnaire to determine flock and household characteristics that facilitate contact with BYC and that may be associated with Salmonella in the BYC environment. Composite faecal material, cloacal swabs and dust samples from 53 flocks housed on 50 residential properties in the Greater Boston, Massachusetts area were tested for Salmonella using standard culture techniques and confirmed using Matrix‐Assisted Laser Desorption/Ionization‐Time of Flight Mass Spectrometer. Microbroth dilution and whole genome sequencing were used to determine phenotypic and genotypic resistance profiles, respectively, and sequence results were used to determine multilocus sequencing type. No owners self‐reported a diagnosis of salmonellosis in the household. Over 75% of a subset of owners reported that they and their children consider BYC pets. This perception is evident in how owners reported interacting with their birds. Salmonella enterica subspecies enterica serotype Kentucky ST152 (serogroup C)—a strain not commonly associated with human infection—was confirmed in one flock, or 2% of tested flocks, and demonstrated resistance to tetracycline and streptomycin. We detected Salmonella at low prevalence in BYC. Further study of the health effects of exposure to zoonotic gastrointestinal pathogens such as Salmonella among families with BYC is warranted.     

Serogroups, atypical biochemical characters, colicinogeny and antibiotic resistance pattern of Shiga toxin-producing Escherichia coli isolated from diarrhoeic calves in Gujarat, India

This study was designed to investigate the antibiotic resistance, colicinogeny, serotyping and atypical biochemical characteristics of 41 Shiga toxin-producing Escherichia coli (STEC) strains detected using polymerase chain reaction from 90 E. coli strains isolated from 46 diarrhoeic calves. The STEC strains belonged to 14 different serogroups. Seventeen per cent of the STEC strains carried the eaeA gene while 14.28% of the 49 non-STEC strains were eaeA positive. Twenty eight (68.29%) of the 41 STEC strains were rhamnose non-fermentors. All the STEC strains revealed resistance to at least three of the antibiotics tested. 100% resistance was found against kanamycin and cephalexin followed by cephaloridine, enrofloxacin, amikacin, ampicillin, tetracycline, ceftiofur, ciprofloxacin, colistin and co-trimoxazole. Eighteen (44%) of the STEC strains produced colicin and all these colicinogenic strains were resistant to three or more antibiotics. Eleven STEC strains (26.82%) showed urease activity. The results of this study suggest that diarrhoeic calves are an important reservoir of STEC strains that are potentially pathogenic for farm animals and humans. Moreover, rhamnose fermentation, colicinogeny and atypical biochemical behaviour, such as urease activity, may serve as important markers or diagnostic tools for epidemiological surveys to trace the source of infection in disease outbreaks.     

Prevalence and antibiotic resistance of mastitis pathogens isolated from dairy herds transitioning to organic management

Changes in udder health and antibiotic resistance of mastitis pathogens isolated from dairies upon conversion from conventional to organic management over a 3-year period was studied. Coagulase-negative staphylococci (CNS) were the most prevalent mastitis pathogens isolated. CNS were significantly less resistant to β-lactam antibiotics when isolated from milk after the herd transitioned to organic management. Cessation of the use of antimicrobial therapies in dairies in combination with organic management could lead to a reduction in the antimicrobial resistance of mastitis pathogens.     

Low levels of antibacterial drug resistance expressed by Gram-negative bacteria isolated from poultry carcasses in New Zealand

Abstract

AIM: To provide baseline data on the levels and patterns of antibacterial drug resistance expressed by Gram-negative bacteria isolated from poultry carcasses in New Zealand.

METHODS: Between July and December 2006, isolates of Escherichia coli (n=407) and Salmonella spp. (n=3) originating from carcass-rinse samples were submitted by testing laboratories affiliated to five major poultry processing plants. Isolates of Campylobacter jejuni (n=193) originating from retail poultry carcasses in 2005–2006 were retrieved from the Massey University archives. All isolates underwent disc diffusion susceptibility testing against panels of 12 (Enterobacteriaceae) and six (Campylobacter spp.) antibacterial drugs. Cephalothin-resistance in isolates of E. coli was confirmed using ETest strips, and confirmation of the resistance phenotypes for a subset of C. jejuni isolates used microbroth dilution assays. Patterns within the resistance phenotypes of the isolates were investigated using hierarchical clustering, and logistic regression modelling.

RESULTS: The majority of isolates (71.5% E. coli, 99% C. jejuni, and all three Salmonella spp. isolates) were fully susceptible to the drugs that were tested. Four (1%) E. coli isolates showed resistance to three or more drugs. The proportions of susceptible E. coli differed between the five processing plants. Resistances were detected in E. coli isolates, using disc diffusion to cephalothin (18.2%), ampicillin (4.4%), tetracycline (4.4%) and gentamicin (1.5%). There was an association between cephalothin-resistant isolates of E. coli and decreased susceptibility to gentamicin. Using ETests to ascertain the minimum inhibitory concentrations (MIC) of E. coli for cephalothin gave inconsistent results. One of 193 C. jejuni isolates was resistant to erythromycin, and microbroth dilution assays confirmed that this panel of C. jejuni was generally susceptible to antibacterial drugs.

CONCLUSIONS: The levels of resistance shown by Gram-negative bacteria isolated from chicken carcasses in New Zealand are among the lowest reported around the world. No resistance to extended-spectrum cephalosporin drugs was detected in E. coli, suggesting that CTX-M and AmpC beta-lactamases are rare or absent. Salmonella spp. are rarely isolated from poultry carcasses during routine testing in New Zealand, and the isolates identified during this study were fully susceptible to the drugs tested. A panel of C. jejuni isolates originating from retail poultry carcasses were susceptible to first-line and second-line antibacterial drugs. The use of cephalothin as a marker of resistance to first-generation cephalosporins may not be appropriate for non-type-specific E. coli of animal origin.     

Antimicrobial resistance in Campylobacter spp. isolated from Ontario sheep flocks and associations between antimicrobial use and antimicrobial resistance

The objectives of this study were to determine the prevalence of antimicrobial resistance (AMR) in faecal Campylobacter spp. from lambs and adult sheep and associations between antimicrobial use (AMU) and AMR. A total of 275 faecal samples collected during initial and final visits from 51 sheep flocks, including one feedlot, across southern Ontario were tested for the presence of Campylobacter spp. Campylobacter jejuni was detected in 52% (143/275) of the faecal samples, Campylobacter coli in 7% (19/275), Campylobacter lari in 1% (2/275) and 2% (4/275) were non-speciated Campylobacter. Broth microdilution was used to test antimicrobial susceptibility of 162 isolates to nine antimicrobials. Campylobacter jejuni isolates (n = 142) were resistant to tetracycline (39%), ciprofloxacin (4%), nalidixic acid (4%) and telithromycin (1%). C. coli isolates (n = 19) were resistant to tetracycline (74%), and azithromycin, clindamycin, erythromycin, and telithromycin (5%). The C. lari isolate displayed resistance to nalidixic acid. No statistically significant associations were found between AMU and AMR during multivariate modelling in this study.     

Analysis of Salmonella enterica serotype Enteritidis isolated from human and chickens by repetitive sequence-PCR fingerprinting, antibiotic resistance and plasmid profiles

A total of 22 Salmonella enterica serotype Enteritidis (S. Enteritidis) strains isolated from human and chicken were subjected to DNA fingerprinting by repetitive sequence PCR using ERIC and BOX primers, antibiotic resistance and plasmid patterns. Both ERIC and BOX PCR amplification data revealed a highly genetic homogeneity between isolates from human and chicken except one isolate, which originated from chicken and showed a different DNA band pattern from others. Eleven of 22 S. Enteritidis isolates (50%) were resistant to more than one antibiotics and characterized by 5 resistance patterns. The most common pattern was penicillin resistant (63.6%). Only one isolate from chicken showed a multiple drug resistance patterns to 4 antibiotics. All 22 S. Enteritidis isolates harbored more than two plasmids with eight different plasmid profiles including two to six plasmids with approximate molecular size ranging from 1.9 to 21 kb. A band of 15 kb size was detected in all isolates tested, however, the band sizes smaller than 15 kb were found only in isolates from chicken.     

野生动物分离菌耐药基因多重PCR检测及序列分析

调查来源于16种四川地区野生动物粪样的24株革兰氏阴性肠杆菌中氨基糖苷类抗生素四种修饰酶基因(am inoglycosides-mod ifying en-zym es,AMEs)的分布情况。应用K-B法进行常规药敏试验,采用多重PCR技术检测分离菌中四种AMEs(aphA3、aacC4、aadA、aacC2)基因并进行序列分析。药敏试验显示分离菌对链霉素的耐药率最高(8/24),对新霉素的耐药率最低(1/24%);多重PCR检测结果显示,aphA3、aa-dA、aacC2基因的检出率分别为:7/24、3/24和2/24,而所有菌株中均未检出aacC4基因;序列分析表明扩增产物与Genbank中的相应序列有很高的同源性(≥97.8%)。     

Prevalence,antimicrobial resistance profile and comparison of selective plating media for the isolation of Salmonella in backyard chickens from Entre Rios,Argentina

This study was conducted to estimate the apparent prevalence of Salmonella spp. in birds kept under backyard system in Entre Ríos, Argentina, and determine the performance of two selective plating media used for Salmonella isolation, and the antimicrobial resistance of the isolated. Also, the association of farms characteristics with Salmonella presence was evaluated. A total of 657 backyard chickens and 15 gooses were sampled one time by cloacal swab, belonging to 51 and one family farms, respectively, and four counties in Entre Rios state from April 2014 to May 2015. Only four samples from backyard chickens belonged to three family farms from Uruguay County were positive to Salmonella spp., so the apparent prevalence was 0.6% for this kind of chicken. Four serovars were isolated (Salmonella ser. Lille, S. ser. Newport, S. ser. Enteritidis and S. ser. Rissen), which were susceptible to all antibiotics tested with the exception of erythromycin. For Hektoen enteric agar and brilliant green agar, relative specificity and positive predictive value were 1, and the relative sensitivity and negative predictive value did not show any difference between them. The agreement was very good between these two plating media. None of the variables studied could be selected to calculate the risk factors associated with Salmonella isolation because p > .15. Although the prevalence of Salmonella spp. is low in backyard birds in Entre Rios, the presence of S. ser. Enteritidis should not be discounted, because it is found in the county that concentrates a large population of intensive poultry production in the state.     

Prevalence of Campylobacter jejuni and its resistance to antibiotics in poultry in the Czech Republic

Thermotolerant Campylobacter spp., in particular Campylobacter jejuni, are among the most frequently identified pathogens, found to be causing human gastrointestinal infections in Europe, with the Czech Republic being no exception. The presented work aimed at assessing results of the first nationwide monitoring of prevalence and antibiotic resistance of Campylobacter spp. in broiler flocks in the Czech Republic, including a comparison of antibiotic resistance of C. jejuni isolates collected from poultry and the human community. The monitoring was carried out in poultry slaughterhouses in 2006 and 2007. From broilers, cloacal swabs were collected and examined. The human isolates of C. jejuni were acquired from rectal swabs in community patients with diarrhoeal diseases. Suspected isolates of both animal and human origin were confirmed by the PCR methods. Antibiotic resistance to selected anti-microbial agents was tested by the microdilution method. In the monitored period, the prevalence of thermotolerant Campylobacter spp. in broilers in the Czech Republic reached almost 50%. In 2006, C. jejuni was detected in 46% and Campylobacter coli in 3% of the tested samples. In 2007, C. jejuni was found in 43% and C. coli in 2% of the samples. The results of anti-microbial susceptibility testing of C. jejuni showed higher resistance in animals when compared with humans. The only exception was tetracycline with higher resistance in isolates of human origin. The highest resistance detected was to quinolone antibiotics. Resistance to oxolinic acid was 77% in animal and 60% in human isolates, to ciprofloxacin 72% in isolates from poultry and 55% in those from humans. In ampicillin, 26% of poultry isolates and 16% of human isolates were resistant. Moreover, 9% of animal isolates demonstrated resistance to streptomycin, undetected in human isolates. In erythromycin, resistance was found in 6% of poultry and 1% of human isolates.     

Antibiotic resistance,ESBL genes,integrons, phylogenetic groups and MLVA profiles of Escherichia coli pathotypes isolated from patients with diarrhea and farm animals in south-east of Iran

The aims of this study were to investigate the prevalence, antibiotic resistance, presence of class 1 and 2 integrons, Extended Spectrum β-Lactamases (ESBL) genes, phylogenetic group and epidemiological relationships of EPEC, ETEC and EHEC pathotypes isolated from patients with diarrhea and farm animals in south east region of Iran. A total of 671 diarrheagenic E. coli (DEC) were collected from stool samples of 395 patients with diarrhea and 276 farm cattles and goats. Presence of EPEC, ETEC and EHEC were identified using multiplex-PCR employing primers targeted the shiga toxin (stx), intimin (eae), bundle forming pili (bfp), and enterotoxins (lt and st) genes. The highest proportion of the patients (64%) were children under age 1–15 year (p ≤ 0.05). Among the isolates, atypical EPEC was detected in 26 patients and 14 animal stool samples, while typical EPEC was found in 2 cattles. ETEC isolates were detected in stools of 13 patients and 4 EHEC was identified in 3 goats and one cattle. The isolates were checked for susceptibility to 14 antibiotics. 50% (n = 13) of EPEC and 61.5% (n =8) of ETEC showed multi-drug resistance (MDR) profiles and one EPEC was found to be extensive drug resistant (XDR). In contrast, EHEC isolates were susceptible to the majority of antimicrobial agents. The MDR isolates were positive for bla_TEM and bla_CTX-M ESBL genes and carried class 1 integrons. Further study on the biofilm formation indicated that, 3 out of 4 EHEC isolates showed strong biofilm, while other pathotypes had either moderate, weak or no biofilm activity. Majority of EPEC isolates were belonged to phylogenetic group B1, all except one ETEC were classified as phylogenetic group A and two EHEC were belonged to phylogroup D, respectively. A multilocus variable tandem repeat analysis (MLVA) exhibited 22 distinct patterns. In conclusion, MLVA data showed high clonal diversity. Presence of EHEC in animal origins pose public health concern in this region.     

宠物源大肠杆菌的血清型和毒力基因及耐药性调查

为研究宠物源致病性大肠杆菌(Escherichia coli)的血清型、毒力基因和耐药性之间的相关性,本研究由健康和患病犬、猫直肠拭子样品中分离177株E.coli,并采用玻片凝集法鉴定其血清型,结果显示分离株中定型菌株135株,分别属于20个不同的血清型,其中O1、O2和O8为主要的流行血清型。PCR方法检测11种毒力相关基因,并采用琼脂稀释法测定分离菌株对14种抗菌药的敏感性,结果表明3个血清型的菌株拥有相似的耐药表型,但毒力基因谱不同。62%的分离菌株携带fimH基因,并且毒力基因组合iroN+hlyF、iroN+fimH和traT+sitA比较流行。55%的O1血清型携带fimH基因,并且多数耐受四环素、多西环素、头孢噻吩和庆大霉素;20.8%的O2血清型菌株携带traT和sitA基因;50%的O8血清型携带traT和fimH基因。3个血清型分离菌株多数对安普霉素和阿米卡星敏感。     

Prevalence and antimicrobial resistance of Campylobacter and Salmonella in layer flocks in Honshu,Japan

Campylobacter and non-typhoidal Salmonella are the major causes of bacterial gastrointestinal infections in humans. Although antimicrobial therapy is typically not recommended in many cases of these infections, it may be life-saving in patients with severe symptoms. Since chicken eggs and meat derived from layers are destined for human consumption, we investigated the prevalence and antimicrobial resistance of these two bacterial genera in 82 layer flocks at chicken processing plants in Honshu, Japan. Campylobacter was isolated from 77 flocks (93.9%). Resistance to ampicillin, tetracycline, and ciprofloxacin was documented in 42.3 (30/71), 16.9 (12/71), and 14.1% (10/71) of Campylobacter jejuni, respectively. Multilocus-sequence typing identified ST4389 and ST5262 as the most frequent C. jejuni sequence types. In C. coli, resistance to ampicillin, tetracycline, and ciprofloxacin was found in 20.0 (7/35), 20.0 (7/35), and 25.7% (9/35), respectively. The most frequent sequence type in C. coli was ST8292. Erythromycin resistance was not observed among Campylobacter species. Salmonella was isolated from 14 flocks (17.1%). The two most frequent serovars were Salmonella Corvallis and S. Braenderup. Neither S. Enteritidis nor S. Infantis were isolated. Streptomycin resistance was observed in six isolates (26.1%), and all isolates were susceptible to cefotaxime and ciprofloxacin. Thus, chicken eggs and meat derived from layers are possible sources of these bacterial infections in humans. The antimicrobial susceptibility of these isolates was maintained, reflecting restrictions on the use of antimicrobial agents on layers.     

细菌排出泵、TolC家族和生物薄膜的作用机制研究进展

在多种重要病原体中存在抗生素排出泵,它与其它抗性一起构成了细菌显著的耐药性,其识别的底物非常广泛.G-菌中还存在与排出泵不同的另一种以蛋白质构成的排出系统,通过底物特异性内膜蛋白和外膜蛋白TolC家族的可逆性互作,也可以直接将包括小分子药物和大分子蛋白毒素等的多种分子从胞浆经周质区运到体外.粘附在内置医疗装置或组织中的细菌因其形成生物薄膜结构和以蛋白质、多糖为主的水性基质包裹的菌体也可以产生长期感染以及对抗生素的持久抗性,这种抗性与经典的质粒、转座子或突变产生的抗性不同.本文对细菌TolC家族和生物薄膜引起的抗性机制进行了综述.     

Analysis of antibiotic resistance phenotypes and genes of Escherichia coli from healthy swine in Guizhou,China

This study was carried out to investigate the resistance phenotypes and resistance genes of Escherichia coli from swine in Guizhou, China. A total of 47 E. coli strains isolated between 2013 and 2018 were tested using the Kirby–Bauer (K–B) method to verify their resistance to 19 common clinical antimicrobials. Five classes consisting of 29 resistance genes were detected using polymerase chain reaction. The status regarding extended-spectrum β-lactamase (ESBL) and the relationship between ESBL CTX-M-type β-lactamase genes and plasmid-mediated quinolone resistance (PMQR) genes were analysed. A total of 46 strains (97.9%) were found to be multidrug resistant. Amongst them, 27 strains (57.4%) were resistant to more than eight antimicrobials, and the maximum number of resistant antimicrobial agents was 16. Twenty antibiotic resistance genes were detected, including six β-lactamase genes blaTEM (74.5%), blaCTX-M-9G (29.8%), blaDHA (17.0%), blaCTX-M-1G (10.6%), blaSHV (8.5%), blaOXA (2.1%), five aminoglycoside-modifying enzyme genes aac(3′)-IV (93.6%), aadA1 (78.7%), aadA2 (76.6%), aac(3′)-II c (55.3%), aac(6′)-Ib (2.1%) and five amphenicol resistance genes floR (70.2%), cmlA (53.2%), cat2 (10.6%), cat1 (6.4%), cmlB (2.1%), three PMQR genes qnrS (55.3%), oqxA (53.2%), qepA (27.7%) and polypeptide resistance gene mcr-1 (40.4%). The detection rate of ESBL-positive strains was 80.9% (38/47) and ESBL TEM-type was the most abundant ESBLs. The percentage of the PMQR gene in blaCTX-M-positive strains was high, and the detection rate of blaCTX-M-9G was the highest in CTX-M type. It is clear that multiple drug resistant E. coli is common in healthy swine in this study. Extended-spectrum β-lactamase is very abundant in the E. coli strains isolated from swine and most of them are multiple compound genotypes.     

Antibiotic resistance,antimicrobial residues,and bacterial community diversity in pasture-raised poultry,swine, and beef cattle manures

Animal manure can be a source of antibiotic-resistant genes (ARGs) and pharmaceutical residues; however, few studies have evaluated the presence of ARG in pasture-raised animal production systems. The objective of this study was to examine changes in microbiome diversity and the presence of antibiotic residues (ABRs) on three farms that contained a diverse range of animal species: pasture-raised poultry (broiler and layer), swine, and beef cattle. Total bacterial communities were determined using 16S rRNA microbiome analysis, while specific ARGs (sulfonamide [Sul; Sul1] and tetracycline [Tet; TetA]) were enumerated by qPCR (real-time PCR). Results indicated that the ARG abundances (Sul1 [P < 0.05] and TetA [P < 0.001]) were higher in layer hen manures (16.5 × 10⁻⁴ and 1.4 × 10⁻⁴ µg kg⁻¹, respectively) followed by broiler chickens (2.9 × 10⁻⁴ and 1.7 × 10⁻⁴ µg kg⁻¹, respectively), swine (0.22 × 10⁻⁴ and 0.20 × 10⁻⁴ µg kg⁻¹, respectively) and beef cattle (0.19 × 10⁻⁴ and 0.02 × 10⁻⁴ µg kg⁻¹, respectively). Average fecal TetA ABR tended to be greater (P = 0.09) for broiler chickens (11.4 µg kg⁻¹) than for other animal species (1.8 to 0.06 µg kg⁻¹), while chlortetracycline, lincomycin, and oxytetracycline ABRs were similar among animal species. Furthermore, fecal microbial richness and abundances differed significantly (P < 0.01) both among farms and specific species of animal. This study indicated that the microbial diversity, ABR, ARG concentrations, and types in feces varied from farm-to-farm and from animal species-to-animal species. Future studies are necessary to perform detailed investigations of the horizontal transfer mechanism of antibiotic-resistant microorganisms (ARMs) and ARG.     

Comparative analysis of antibiotic resistance characteristics of Gram-negative bacteria isolated from laying hens and eggs in conventional and organic keeping systems in Bavaria, Germany

By investigating the prevalence and resistance characteristics of Gram-negative bacteria from organic and conventional kept laying hens against 31 (Campylobacter: 29) different antibiotics using the microdilution method, we determined to what extent different keeping systems influence bacterial resistance patterns. For this purpose, samples from 10 organic and 10 conventional flocks in Bavaria (Germany) were investigated four times between January 2004 and April 2005. Altogether, 799 cloacal swabs and 800 eggs (contents and shells) were examined. The bacterial investigation performed with standardized cultural methods showed prevalence for all bacteria groups in about the same order of magnitude in the two different keeping systems: Salmonella spp. 3.5% (organic ([org])) versus 1.8% (conventional ([con])); Campylobacter spp. 34.8%(org) versus 29.0%(con) and E. coli 64.4%(org) versus 69.0%(con). Coliforms (Citrobacter, Enterobacter, Pantoea) were only isolated in single cases. In eggs, generally less bacteria were detected, predominantly Escherichia; Salmonella and Campylobacter were only scarcely isolated. Salmonella enterica ssp. enterica serovar Typhimurium (n=10) were resistant to up to nine, S. of the serogroup B (n=4) up to six antibiotics. All tested Salmonella (n=23) proved to be resistant to spectinomycin. Escherichia coli (n=257(org) and 276(con)) from organic layers showed significant lower resistance rates and higher rates of susceptible isolates to nine agents, namely amoxicillin/clavulanic acid, ampicillin, cefaclor, cefoxitin, cefuroxime, doxycycline, mezlocillin, neomycin and piperacillin. In contrast, only two antibiotics turned out to be more effective in conventional isolates (gentamicin and tobramycin). In the case of Campylobacter jejuni (n=118(org) and 99(con)), statistically significantly better rates were observed for isolates from organic flocks concerning imipenem and amoxicillin/clavulanic acid, whereas fosfomycin was more potent in strains from conventional flocks. Results of this study indicate that both resistance rates and mean minimum inhibitory concentrations of bacteria isolated from organic keeping systems have lower values than those from conventional ones, particularly recognizable for E. coli. Thus, organic livestock farming with its restrictions and additional requirements contributes to further effectiveness of antibiotics.     

我国健康猪源大肠杆菌对四环素类药物耐药性的Meta分析

旨在系统评价我国健康猪源大肠杆菌对四环素类药物耐药性的情况,为养殖业合理用药决策提供依据.计算机搜索PubMed、Web“sci-ence、SinoMed、CNKI等10个数据库.应用Revman 5.3软件进行Meta分析,并对各研究间异质性进行评价.共纳入20篇符合条件的研究,共4 343株分离自健康猪源的大肠杆菌...     

Antimicrobial resistance pattern of Salmonella serotypes isolated from food items and personnel in Addis Ababa, Ethiopia

Antimicrobial susceptibility test of 98 isolates of Salmonella was assayed from September 2003 to February 2004 using the guidelines of the National Committee for Clinical Laboratory Standards (NCCLS).The result revealed that 32.7% of Salmonella isolates were resistant to one or more of the 24 antimicrobials tested. Generally resistance for 13 different antimicrobial drugs was recognized. The most common resistance was to streptomycin (24/32, 75%), ampicillin (19/32, 59.4%), tetracycline (15/32, 46.9%), spectinomycin (13/32, 40.6%) and sulfisoxazole (13/32, 40.6%). All the three Salmonella Kentucky isolates showed resistance to at least 8 antimicrobials. Out of the 12 Salmonella Braenderup isolates, 10 (83.3%) showed multidrug resistance to ampicillin, spectinomycin, streptomycin, sulfisoxazole, sulfamethoxazole/trimethoprim, amoxicillin/clavulanic acid and trimethoprim. Among the 8 S. Hadar isolates 7 (86.5%) showed antimicrobial resistance. All the 6 S. Dublin isolates were resistant to carbadox (100%). All the 6 S. Haifa isolates were resistant for at least ampicillin, streptomycin and tetracycline. Up to ten different antimicrobial resistances pattern was observed. Multiple antimicrobial drug resistance was observed in 23 Salmonella isolates (23.5%). The level of antimicrobial resistance was significantly higher for isolates from chicken carcass (18/29, 62.1%) and pork isolates (5/22, 22.7%) (p = 0.003). The findings of the present study ascertain that significant proportion Salmonella isolates have developed resistance for routinely prescribed antimicrobial drugs and poses considerable health hazards to the consumers unless prudent control measures are instituted.     

Phylogenetic groups and cephalosporin resistance genes of Escherichia coli from diseased food-producing animals in Japan

A total of 318 Escherichia coli isolates obtained from different food-producing animals affected with colibacillosis between 2001 and 2006 were subjected to phylogenetic analysis: 72 bovine isolates, 89 poultry isolates and 157 porcine isolates. Overall, the phylogenetic group A was predominant in isolates from cattle (36/72, 50%) and pigs (101/157, 64.3%) whereas groups A (44/89, 49.4%) and D (40/89, 44.9%) were predominant in isolates from poultry. In addition, group B2 was not found among diseased food-producing animals except for a poultry isolate. Thus, the phylogenetic group distribution of E. coli from diseased animals was different by animal species. Among the 318 isolates, cefazolin resistance (minimum inhibitory concentrations: ≥32 μg/ml) was found in six bovine isolates, 29 poultry isolates and three porcine isolates. Of them, 11 isolates (nine from poultry and two from cattle) produced extended spectrum β-lactamase (ESBL). The two bovine isolates produced bla_CTX-M-2, while the nine poultry isolates produced bla_CTX-M-25 (4), bla_SHV-2 (3), bla_CTX-M-15 (1) and bla_CTX-M-2 (1). Thus, our results showed that several types of ESBL were identified and three types of β-lactamase (SHV-2, CTX-M-25 and CTX-M-15) were observed for the first time in E. coli from diseased animals in Japan.     

Antibiotic resistance in Escherichia coli isolates from poultry environment and UTI patients in Kerala,India: A comparison study

BackgroundThere are only narrow insights regarding the antimicrobial resistance of pathogens in poultry environment in India and its transmission to humans. The use of antimicrobials in food animal production is not properly regulated in India. So, many clinically important antimicrobials are used indiscriminately.ObjectiveOur aim was to do a comparative analysis of antibiotic resistance in Escherichia coli isolates from poultry environment and UTI patients.MethodologyTwo poultry farms each from six areas in Muvattupuzha region of the state of Kerala in India were selected for the study. From each farm, samples of fresh fecal matter, litter from inside the shed, litter from outside the shed, nearby agricultural soil and control soilwere collected. E. coli was isolated from each sample, and antimicrobial susceptibility testing of E. coli was done with fifteen antibiotics. Antibiograms of UTI patients were collected from the tertiary care hospital included in the study and those were compared with the antibiograms of poultrysamples.ResultAll samples were resistant to ampicillin, amoxicillin, meropenem and tetracycline. Similar resistance pattern in poultry environment and UTI patients was seen for antibiotics such as ampicillin, amoxicillin, amikacin, and ofloxacin. A statistically significant difference (p < .00601) was established in the total number of isolates resistant to various antibiotics from areas near to farms compared to those away from farms.ConclusionE. coli were resistant not only to extended spectrum beta lactams but also to carbapenems which might have disseminated to environment where litter was used as manure. This might be due to irrational use of antibiotics in chicken and poultry feed as growth promoter.