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1.
Non-typhoid Salmonella serovars remain a potential threat to human health, and beef cattle and broiler chickens are possible sources of these organisms on Prince Edward Island (PEI). In this study, the ceca of beef cattle belonging to fasted and non-fasted groups, and broiler chickens were examined for Salmonella at the time of slaughter. The characteristics of the isolates, including antimicrobial resistance patterns and virulence genes, were studied along with the isolates obtained from cases of human salmonellosis on PEI during the study period (1996–97). The prevalence of Salmonella in beef cattle was 4.6% (11/240). The rate was significantly higher in fasted cattle (7.46%), than in non-fasted cattle (0.94%). The prevalence rate in chickens was 32.5% (39/120). In beef cattle, Salmonella typhimurium phage type (PT) or definitive type (DT) 104 which was resistant to ampicillin, chloramphenicol, streptomycin, sulfisoxazole and tetracycline, was the most predominant type (64%). In chickens, S. heidelberg, with resistance to gentamicin, streptomycin and sulfisoxazole, predominated. Of 26 isolates from humans, the most common serovar was S. typhimurium, including a multidrug-resistant strain of DT104. Examination by PCR revealed presence of the virulence gene invA in all serovars, and the spvC gene in all S. typhimurium isolates, of both beef cattle and human origin. Among the other serovars the latter gene was found in 7 human isolates, but in none of the chicken or beef isolates. All but 3 of the spvC-positive isolates possessed a 90 kilobasepair (kbp) plasmid suggesting that the 3 isolates had the spvC gene on their chromosome. These findings were confirmed by plasmid DNA isolation using 3 different protocols and by sequence analysis of the spvC-PCR product.  相似文献   

2.
为了解动物沙门氏菌的流行情况和药物敏感性及氟苯尼考耐药株的耐药基因分布,本试验对临床上疑似患沙门氏菌病的病料进行病原分离和细菌的多重PCR鉴定;采用K-B法测定分离株对23种抗菌药物的敏感性;选择氟苯尼考耐药菌株扩增floR、fexA、fexB、cfr和pexA基因。结果显示,共鉴定出61株沙门氏菌,其中肠炎沙门氏菌10株,鸡白痢沙门氏菌12株,鼠伤寒沙门氏菌39株。所有菌株对青霉素、红霉素、万古霉素耐药,90.16%对6种及6种以上抗菌药耐药。floR基因广泛存在于鼠伤寒沙门氏菌氟苯尼考耐药菌株中(8/12,66.67%),未发现其他耐药基因。研究结果表明鼠伤寒沙门氏菌是鹅源分离株中的优势血清型;floR基因主要介导沙门氏菌对氟苯尼考耐药性,但可能还存在其他机制。  相似文献   

3.
四川省部分地区山羊沙门氏菌健康带菌率及耐药性调查   总被引：2，自引：1，他引：1  
为了解四川省山羊沙门氏菌带菌情况,本试验采集了四川省部分地区5个规模化山羊养殖场表观健康山羊粪便196份,经BPW预增菌、TTB选择性增菌后,采用靶向invA基因的PCR方法检测沙门氏菌的带菌率;对阳性样本进行细菌分离鉴定,随机选择25株沙门氏菌分离株测定其对15种抗菌药物的敏感性。结果显示,山羊沙门氏菌的平均带菌率为54.59%。药敏试验结果显示,分离株均对丁胺卡那敏感,而对其余14种抗菌药物呈不同程度的耐药,多重耐药菌株占88%,其中耐2~7种药物的占52%,耐9~13种药物的占36%。结果表明,四川省部分地区山羊的沙门氏菌健康带菌率较高,且多重耐药性普遍,其公共卫生意义值得进一步研究。  相似文献   

4.
Increasing emergence of salmonellosis presents a threat to the effective control of foodborne disease in humans. The purpose of this study was to evaluate the prevalence of drug susceptibility and molecular characteristics of non-typhoidal Salmonella (NTS) isolated from laying hens (LH) in 3 Moroccan regions, Rabat-Salé-Zemmour-Zaër (RSZZ), Souss-Massa-Drâa (SMD), and the grand Casablanca (GC). A total of 351 samples were collected from 30 consumer egg laying houses at the end of the egg laying period from April to July 2011. Sixty-four out of these 351 examined samples were contaminated by Salmonella. The Salmonella isolated strains were then serotyped and tested for drug susceptibility and analyzed by polymerase chain reaction (PCR) for the presence of the invasion-associated genes invA and spvC and nalidixic acid resistance-associated qnr gene. The prevalence of NTS infection in LH was estimated to be 73.3%. Seven Salmonella enterica serovars were identified: Enteritidis (37.5%), Kentucky (31.2%), Infantis (10.9%), Typhimurium (6.2%), Thompson (6.2%), Agona (4.6%), and Amsterdam (3.1%). Drug susceptibility testing showed that 65.6% of Salmonella were resistant to at least one antibiotic and 25% were resistant to ciprofloxacin. All isolates were positive for the invasion gene invA and 28% of them were positive for the virulence gene spvC. All nalidixic acid-resistant S. Enteritidis isolates were negative for qnr plasmid genes. Our findings clearly suggest the necessity to establish an NTS monitoring and control program for LH in Morocco.  相似文献   

5.
Nasal secretions, faecal samples and buffy coats were obtained from 102 cattle from a North Dakota dairy herd with a history of calf scours. Treated buffy coats, faecal samples and nasal secretions were inoculated into tetrathionate broth (TB), incubated at 37°C overnight, and plated onto brilliant green agar medium with novobiocin (BGAN). The TB was left at room temperature for 5 days and then used to inoculate fresh TB. The fresh TB was incubated at 37°C over night and plated onto BGAN medium. All the plates were incubated at 37°C over night and observed forSalmonella-like growth. Suspect colonies were further tested andSalmonella isolates were serotyped by the National Veterinary Services laboratory. Twenty-two of the 36 calves sampled harbouredS. typhimurium in their faeces, but no samples from cows were positive. NoSalmonella were isolated from the buffy coats, but 4 calves were shown to haveSalmonella in their nasal secretions. Extended enrichment of the faecal cultures in TB resulted in a significant increase inSalmonella isolations, although 2 samples were positive following the initial enrichment period and not after secondary enrichment. The typicalSalmonella isolate detected from this herd contained a transmissible R-plasmid encoding resistance to tetracycline, kanamycin, sulphisoxazole and ampicillin. This study confirmed that delayed secondary enrichment in TB is superior to primary enrichment for detection ofSalmonella from cattle.Abbreviations Ap ampicillin - BGAN brilliant green agar with novobiocin - Cm chloramphenicol - DSE delayed secondary enrichment - Gn gentamicin - Kn kanamycin - NA nalidixic acid - NADC National Animal Disease Center in Ames, Iowa - NVSL National Veterinary Services Laboratory in Ames, Iowa - PB polymyxin B - PE primary enrichment - Sm streptomycin - Su sulphisoxazole - TB tetrathionate broth - Tc tetracycline - TSI triple sugar iron agar  相似文献   

6.
Salmonella enterica serovars Typhimurium, Enteritidis, Dublin, Choleraesuis or Gallinarum can colonise liver and spleen in particular hosts while infections with serovars Infantis, Agona, Hadar, etc. are usually limited to gastrointestinal tract. Reasons for this behavior are unknown, although it has been shown that sodCI and spv genes exhibit a strict distribution between more and less virulent serovars and they influence Salmonella virulence. However to what extent the presence or absence of these genes is associated with the increased virulence of serovars which possess them has never been addressed experimentally. In this study we therefore first confirmed the exclusive association of spvB and sodCI genes with the former group of serovars. In the next step we removed these two genes from S. Enteritidis genome and compared the virulence of such a mutant with the virulence of S. Infantis, S. Agona and S. Hadar for chickens and highly sensitive Balb/C mice. Single strain infection showed that the deletion of these two genes from S. Enteritidis resulted in the reduction of its virulence for mice but not for chickens. Mixed infection further confirmed these observations and indicated that in mice but not in chickens the virulence of sodCI and spv mutant was reduced to the natural virulence of serovars Infantis, Agona and Hadar. Although sodCI and spv genes do not influence S. Enteritidis virulence for chickens directly, they may be of an indirect effect through the increased persistence of S. Enteritidis in mice and increased probability of the reintroduction of S. Enteritidis into poultry flocks.  相似文献   

7.
The quinolone resistance-determining regions (QRDRs) of the gyrA gene of quinolone-resistant Salmonella enterica serovar Choleraesuis isolates were sequenced. Four types of point mutation, Ser-83-to-Phe (TCC→TTC), Ser-83-to-Tyr (TCC→TAC), Asp-87-to-Gly (GAC→GGC), and Asp-87-to-Asn (GAC→AAC), were found. PCR-RFLP and MAS-touch down PCR were performed on fifty swine clinical isolates of S. enterica serovar Choleraesuis (NalR) collected during 1997–2002. The analysis indicated seven isolates with point mutations in codon 83, 13 with point mutations in codon 87, and 30 with double mutations in both codons 83 and 87. The MICs of enrofloxacin of the isolates with a single mutation in codon 83 or 87 were <2 μg/ml, while the MICs of the isolates with double mutations in both codon 83 and 87 ranged from 2 to 64 μg/ml. A class I integron comprised of dhfr, orfF and aad2 was also identified in both human and swine S. enterica serovar Choleraesuis isolates. These results indicate that PCR-RFLP and MAS-touchdown PCR assays can be used for surveillance of gyrA gene mutations, which are important for fluoroquinolone resistance in Salmonella. Isolates with double mutations in gyrA codons 83 and 87 are the major type of quinolone-resistant Salmonella isolated from swine in Taiwan. A surveillance system may be applied to the swine industry to monitor the emergence of fluoroquinolone and/or multi-drug-resistant S. enterica serovar Choleraesuis in Taiwan.  相似文献   

8.
Salmonellosis is a major bacterial disease causing huge economic losses in the poultry industry worldwide. This study was carried out to determine the period prevalence and antimicrobial susceptibility of Salmonella enterica in Japanese quails in Abeokuta, Nigeria. Four hundred cloacal swabs of quail birds were collected from 4 locations within Abeokuta. Salmonella was isolated from the samples using conventional methods for selective isolation of Salmonella and biochemical identification. Isolates were confirmed by polymerase chain reaction assays for the amplification and detection of Salmonella-associated virulence genes (invA and stn) using specific primers. Antimicrobial susceptibility testing was done using the Kirby-Bauer disk diffusion method. In all, Salmonella was isolated from 14 (3.5%) cloacal swabs. All 14 isolates possessed invA and stn genes. The Salmonella isolates showed resistance to tetracycline (100%), doxycycline (100%), ampicillin (100%), sulphamethoxazole (92.9%), nalidixic acid (85.8%), ceftazidime (78.6%), neomycin (64.3%), streptomycin (50%) and gentamycin (28.6%) but all the isolates were susceptible to ciprofloxacin. The isolates were resistant to at least three antimicrobials indicating multidrug resistance. The results concluded that Japanese quails harbour multidrug-resistant Salmonella which could be transmitted to humans through consumption of contaminated food or by direct and indirect contact with the carrier birds. Antimicrobial resistance could be due to overdependence on antimicrobials. Ciprofloxacin could be considered in the treatment of zoonotic Salmonellosis in humans.  相似文献   

9.
The prevalence and antimicrobial resistance pattern of Salmonella isolates was determined from apparently healthy slaughtered cattle at Debre Zeit (Ethiopia). A total of 323 cattle were examined for the presence of Salmonella in faeces, mesenteric lymph nodes, abdominal and diaphragmatic muscles. Salmonellae were cultured from 23 (7.1%) of the animals. Salmonellae were isolated from 2 (3.1%) and 3 (4.5%) of 65 pooled faecal and mesenteric lymph node samples, respectively. Nine (2.8%) abdominal muscle and 10 (3.1%) diaphragmatic muscle samples (n = 323 of each) were contaminated by Salmonella. About 60% of the serovars identified in the abdominal and diaphragmatic muscles were also detected from faeces and mesenteric lymph node samples. The five different serovars isolated were Salmonella mishmarhaemek (48%), S. typhimurium (20%), S. enteritidis (12%), S. guildford (12%) and S. dublin (48%). The antimicrobial resistance profiles of 25 of the Salmonella isolates with 17 antimicrobials showed that 52% (13/25) of them were resistant to three or more antimicrobials. Both strains of Salmonella (S. mishmarhaemek and S. typhimurium) showed multiple resistance to ampicillin, sulfamethoxazole and ticarcillin. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

10.
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.  相似文献   

11.
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.  相似文献   

12.
The objective of this study was to investigate the occurrence of major bacterial foodborne pathogens in swine. In total, 359 samples from manure storage tanks (91) and fresh pooled faeces (268) obtained from finisher (110), sows (78) and weanlings (80) were collected and tested. Campylobacter, Salmonella, Yersinia enterocolitica, Escherichia coli O157 and Listeria monocytogenes were isolated from 36.5%, 31.5%, 5.8%, 3.3% and 3.3% of samples respectively. All E. coli O157 isolates found on 10 farms were tested but none was determined to be E. coli O157:H7. Salmonella and Campylobacter were more likely to be detected from stored manure rather than from fresh faecal samples. Yersinia enterocolitica tended to be detected more commonly from fresh samples than from manure pits. Listeria monocytogenes was not recovered from manure pits or from sow faecal samples and only infrequently found in the faeces of weanling pigs and finisher pigs. The proportion of positive samples showed a seasonal change. Salmonella was twice as likely not be recovered in winter, whereas the chance of culturing Campylobacter was higher in winter. The 113 Salmonella isolates recovered on 24 farms and the four most common serovars were Salmonella Typhimurium var. Copenhagen (31.0%), Salmonella Derby (12.4%), S. Typhimurium (10.6%) and Salmonella Agona (10.6%). Of 131 Campylobacter isolates recovered on 21 farms, 118 isolates were Campylobacter coli and 13 isolates could not be speciated. Fifteen of 21 Y. enterocolitica isolates found on 15 farms were detected in finisher pigs. The sero/biogroups of Y. enterocolitica were O3/biotype 4 (16 isolates), O6,30/biotype 1A (three isolates), O5/biotype 1A (one isolate) and O8/biotype 1B (one isolate). These findings provide baseline information on the distribution of important zoonotic pathogens in swine and indicate that pigs should be considered as a possible source of foodborne diseases in humans.  相似文献   

13.
Salmonella enterica remains one of the most important food-borne pathogens of humans and is often acquired through consumption of infected poultry meat or eggs. Control of Salmonella infections in chicken is therefore an important public health issue. Infection with S. enterica serovar Typhimurium results in a persistent enteric infection without clinical disease in chickens of more than 3 days of age, and represents a source for contamination of carcass at slaughter and entry into the human food chain. Data presented indicate a profound effect of age at initial exposure on the persistence of infection and a lesser effect on the development of effective immunity to re-challenge. The percentage of birds positive for Salmonella was high until 8–9 weeks of age, regardless of the age at which the birds were infected (1, 3 or 6 weeks). The birds infected at 3 and 6 weeks of age produced a more rapid and higher antibody response (IgY and IgA) than those infected at 1 week of age, but in all cases infection persisted for a considerable period despite the presence of high antibody levels. Following a re-challenge infection with S. Typhimurium, all three previously-infected groups had fewer bacteria in the gut, spleen and liver compared with age-matched birds receiving a parallel primary infection. However, the birds primary infected at 3 and 6 weeks of age cleared infection more rapidly than those infected at a younger age. Interestingly older-primed birds had higher specific T lymphocyte proliferative responses and specific circulating levels of IgY antibody at time of re-challenge. Although birds initially infected at 1 week of age and those that were previously uninfected produced a stronger antibody response following re-challenge, they were slower to clear Salmonella from the gut than the older-primed groups which expressed a stronger T lymphocyte response. The data presented indicate that clearance of Salmonella from the gut is age-dependent and we propose that this relates to the increased competence of the enteric T cell response. The findings that Salmonella persists beyond 8–9 weeks, irrespective of age at exposure, has implications for the broiler sector and indicates the need to remain Salmonella free throughout the rearing period. Moreover, the re-challenge data demonstrates that infection at a young age is less effective in producing protective immunity than in older chickens. This feature of the development of protective immunity needs to be considered when developing vaccines for the broiler sector of the poultry industry.  相似文献   

14.
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.  相似文献   

15.
This study evaluated the suitability of invA gene amplification by PCR as an effective means of detecting Salmonella species in pigs experimentally infected with S. Typhimurium DT104. A controlled infection study using 24 pigs was performed in order to compare efficacy, precision and detection rates of the invA‐based PCR method originally described by Rahn, K. De Grandis, S.A., Clarke, R.C., McEwan, S.A., Galan, J.E., Ginocchio, C., Curtiss, R. 3rd, C.L. Gyles, (Mol. Cell. Probes 1992; 6 : 271–279) as a new in‐house invA‐based PCR method for the specific detection of Salmonella spp. in pork and different tissue samples of slaughter pigs. Finally, PCR results were compared with culture detection rates obtained by isolation procedures following the ISO 6579:2000, the ‘gold standard’. After slaughtering, 14 different tissue samples of each pig were investigated to verify the usefulness of the two invA‐based PCR methods in different matrices of slaughter pigs. The results demonstrate that the application of the widely used invA‐based primer pair (139 + 141) may result in questionable products if samples gained from selective enrichment in the Rappaport–Vassiliadis medium were investigated. These questionable products can lead to false‐positive results, if no additional hybridization procedure is attached or if unspecialized persons use this method in routine laboratory practice. The newly developed in‐house PCR method used is based on the 3′‐prime region of invA, especially designed and harmonized for the detection of Salmonella in different matrices of slaughtered pigs after bacterial enriched broth culture. In this study, this PCR revealed no questionable products and, furthermore, the specificity of the amplificate could be tested by means of the restriction enzyme NdeI. In comparison with the culture detection procedure, the new PCR method has a sensitivity of 100% and a specificity of 96%. Thus, this method might be used as a meaningful tool in eliminating Salmonella‐positive carcasses at slaughterhouse level and thus, keeping them out of the food chain.  相似文献   

16.
Twenty-four strains of Salmonella enteritidis, isolated from several outbreaks of salmonellosis from different poultry farms in India, were checked for the plasmid profile and detection of virulence gene(s) by PCR. Most of the strains contained only a single plasmid of 55 kb. Additional plasmids of 23.2 kb and 8.7 kb were seen in one of the strains, and another strain carried only two plasmids of 23.2 kb and 8.7 kb. Four strains did not carry any plasmid. PCR amplification showed the presence of virulence-associated genes in all the isolates harbouring the 55 kb plasmid. Intraperitoneal inoculation of mice, with most of the strains carrying the 55 kb plasmid, caused 100% mortality. Most strains lacking the 55 kb plasmid were avirulent. In chickens, oral inoculation of the S. enteritidis strains carrying the 55 kb plasmid produced 40–100% mortality, with characteristic signs of salmonellosis. Oral inoculation of strains lacking the 55 kb plasmid did not cause any mortality. Hence, it appears that the large plasmid of S. enteritidis probably contributes towards virulence in mice and chickens.  相似文献   

17.
Colisepticaemia is a major health and economic concern for the mink industry, yet little information is available about the Escherichia coli that cause this disease. In this study, 40 E. coli, isolated from mink clinically diagnosed with colisepticaemia that had been submitted to the North Dakota State University Veterinary Diagnostic Laboratory, were randomly selected for characterization. These isolates were serotyped and screened for resistance to 18 antimicrobials, possession of transmissible R plasmids, and the presence of several virulence traits or genes using bioassays or the polymerase chain reaction. Several serotypes were identified that have previously been associated with septicaemia in other animal species. The majority of the isolates exhibited multiple antimicrobial resistance phenotypes. Common resistance phenotypes observed included those to tetracycline, sulfamethoxazole, streptomycin, ampicillin and kanamycin. Several of the isolates that could be studied by conjugation contained transmissible R plasmids coding for multiple antimicrobial resistance phenotypes. About half of the isolates produced colicin; all produced enterobactin; and all but one-quarter produced aerobactin. None of the isolates tested produced enterohaemolysin, and one-fifth were considered to be beta haemolytic. About half appeared to contain the gene encoding cytotoxic necrotizing factor-I; three contained the gene encoding EAE, but none appeared to contain the genes coding for LT, Sta/b, SLT-I/II or CNF-II toxins or K99 antigen. Approximately one-third of the isolates elaborated capsule. The results show that the E. coli isolates implicated in mink colisepticaemia possess similar virulence traits and antimicrobial resistance phenotypes to those associated with diarrhoeal diseases in food animals.  相似文献   

18.
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.  相似文献   

19.
We examined 872 equids (445 maintained by low-income individuals and 427 maintained on nine designated equine farms) and, using previously described methods for bacteria, isolated Salmonella from fecal samples of 59 (6.77%) animals. Of the 646 horses, 183 donkeys, and 43 mules that had feces cultured for Salmonella, 42 (6.5%), 7 (3.8%), and 10 (23.3%), respectively, were excreting Salmonella strains in feces. Six horse mares were excreting Salmonella enterica of two different serovars simultaneously. A total of 65 Salmonella enterica isolates belonged to 13 serovars, namely S. paratyphi B var Java (14), S. I. 4, 5, 12, 27: r, i: 1, 5 (11), S. Drogana (8), S. Newport (7), S. Saintpaul (5), S. Lagos (4), S. Typhimurium (5), S. Kottbus (3), S. Bovismorbificans (3), S. Dumfries (2), S. Tshiongwe (1) S. Weltevreden (monophasic) (1), and S. enterica ssp salamae (1). With Salmonella-specific polymerase chain reaction (PCR) using hisJ gene primers, 107 (12.3) fecal samples yielded a specific amplicon of 496 bp. On using PCR, prevalence of Salmonella in donkeys, horses, and mules was 4.9%, 10.8%, and 65.1%, respectively. With both methods of Salmonella detection in feces, prevalence was significantly higher in female than in male donkeys and horses. Salmonella shedding in feces was significantly higher in equids maintained by low-income people than those at designated equine farms. Almost all Salmonella isolates (63 of 65) had multiple-drug-resistance (MDR, resistance to three or more drugs). Salmonella isolates were commonly resistant to sulfamethoxazole (90.8%), tetracycline (70.8%), doxycycline (67.7%), furazolidone (66.2%), and colistin (55.4%). A few isolates had resistance to trimethoprim (3.1%), ciprofloxacin (3.1%), ceftriaxone (3.1%), ceftazidime (3.1%), cefoperazone (3.1%), chloramphenicol (4.6%), cefotaxime (6.2%), gentamicin (9.2%), ampicillin + cloxacillin (9.2%), cotrimoxazole (13.8%), kanamycin (13.8%), amoxicillin + clavulanic acid (16.9%), imipenem (16.9%), ampicillin (18.5%), amikacin (23.1%), neomycin (27.7%), nalidixic acid (33.8%), and streptomycin (36.9%). With the exception of 13 Salmonella isolates of S. Drogana (4), S. Newport (4), S. I. 4, 5, 12, 27: r, i: 1, 5 (4) and S. Kottbus (1) serovars, all had one or more than one plasmid. Molecular weight of plasmids ranged between 3 kDa and >87 kDa. One heavy plasmid (≥87 kda) was present in all the 52 plasmid-positive strains. Presence of plasmid could not be correlated with MDR in Salmonella isolates from equids.  相似文献   

20.
Forty-six Salmonella enterica subspecies enterica serovar Enteritidis (S. Enteritidis) strains were isolated from chicken meat, faeces, and eggshells collected from hatcheries throughout Korea. The strains were examined for the presence of antimicrobial resistance and virulence genes. All 46 isolates were resistant to at least one of 21 antibiotics used in this study, 30 (65.2%) were resistant to three or more antimicrobials, and a single remarkable isolate was resistant to 15 antimicrobials. The isolates were primarily resistant to penicillins, sulfisoxazole, streptomycin, tetracycline and quinolones.The high rate of resistance in S. Enteritidis strains, sometimes to multiple drugs, may complicate future options for treating human infections. Nineteen of the 21 penicillin resistant isolates carried the blaTEM gene, while one strain, resistant both to penicillins and ceftriaxone, carried the blaCTX-M gene. Thirty-seven of the 45 sulfisoxazole resistant isolates carried sul2, and 23/24 streptomycin resistant isolates carried both strA and strB. All 10 tetracycline resistant isolates carried the tet(A) gene. Most isolates harboured both SPI-1 and SPI-2-associated genes, and the spv operon, which are known to be associated with human infections. The presence of these genes suggests that these strains could give rise to public health problems if dispersed in the general human population.  相似文献   

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