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1.
Isolates of extended-spectrum cephalosporin (ESC)-resistant Salmonella enterica serovar Typhimurium obtained from two different farms in Fukushima Prefecture, Japan, in 2007 were characterized in order to determine the genetic basis of resistance. ESC resistance in the two isolates was mediated by an AmpC β-lactamase encoded by the bla(CMY-2) gene, which is located in a large self-transmissible plasmid in each isolate. The sizes of the bla(CMY-2)-carrying plasmids were different. The replicon types of the plasmids were I1-Iγ and A/C. The results of macrorestriction analysis and phage typing suggest a close relationship between both isolates. This is the first report of ESC-resistant S. Typhimurium isolated from cattle in Japan.  相似文献   

2.
Salmonella Livingstone is occasionaly isolated from humans, animals and feedstuffs in Sweden. To follow the spread of infection and trace the source of isolates, adequate typing methods are needed. We have developed an automated typing system based on biochemical fingerprinting of bacteria (the PhP system) for typing of different Salmonella serotypes. The system measures the kinetics of various biochemical reactions of bacteria grown in liquid medium in microtiter plates and uses numerical techniques to identify biochemical phenotypes (BPTs) among the tested strains. In the present study we used a set of 16 highly discriminatory tests to differentiate strains of Salmonella of serotype Livingstone and evaluated the system for its discriminatory ability using a collection of 34 unrelated human isolates of S. Livingstone. We also used the system to investigate BPTs of 45 Livingstone strains isolated from animals and feedstuffs in Sweden between 1987 and 1991. Altogether 19 different BPTs were found among human isolate giving a diversity index (Di) of 0.930. In contrast, most strains isolated from animals and feedstuffs in Sweden belonged to 2 dominating BPTs (Di = 0.704). One of these contained 17 strains mainly isolated during 1992 whereas the other contained 18 strains isolated between 1987 and 1991. None of the Swedish human isolates were identical to those of animals and feedstuffs. These findings suggest that 2 different BPTs of Salmonella Livingstone strains are particularly common among animals and feedstuffs in Sweden and that they are not related to human cases of enteritis in this country. We also conclude that biochemical fingerprinting with the PhP system is a reliable and highly discriminatory method for detecting epidemic strains of Salmonella Livingstone.  相似文献   

3.
Although Salmonella remains one of the leading causes of foodborne illnesses in the United States, the Salmonella enterica serovars and genetic types associated with most infections appear to fluctuate over time. Recently, the Center for Disease Control and Prevention (CDC) has reported an increase in cases of salmonellosis caused by Salmonella 4,[5],12:i:-. Similarly, this unusual Salmonella serovar has been isolated from cattle and poultry in the state of Georgia. We examined the genetic relatedness of Salmonella 4,[5],12:i:-, isolated from several different poultry companies and dairy farms in Georgia, by pulsed-field gel electrophoresis (PFGE). Several Salmonella 4,[5],12:i:- isolates had PFGE patterns identical or similar to PFGE patterns of Salmonella Typhimurium isolated from numerous animal sources. We identified distinct PFGE patterns for Salmonella 4,[5],12:i:- and matching Salmonella Typhimurium PFGE patterns, identifying four "distinct" strains. We focused a more specific analysis on the poultry Salmonella 4,[5],12:i:- and Salmonella Typhimurium isolates and found that of these Salmonella 4,[5],12:i:- isolates, 32% lacked the entire phase 2 antigen gene, fljB; 61% contained partial deletion(s); and 4% had partial deletion(s) in fljB and an adjacent gene hin, 5' to fljB. Thirteen percent contained smaller deletions or point mutations not identified by our DNA probes. The Salmonella 4,[5],12:i:- isolates were positive for several genes present in the Salmonella Typhimurium, including lpfE (100%), sseI(96%), and spvC (93%). Genetic analysis indicates independent, spontaneous mutations in fljB in at least four distinct Salmonella Typhimurium strains of animal origin circulating in nature.  相似文献   

4.
From 10 egg production poultry farms 1516 samples were collected and examined for the presence of salmonella. The samples were: 201 chicken, 36 sparrows, 35 rats, 35 pools of 20 flies each, 450 eggs, 60 mattresses, 188 feces, 425 feedstuffs and 86 water samples. Salmonellae were isolated only from 163 (10.8%) samples. From the 146 (89.6%) of these S. gallinarum was isolated. From the rest 17 (10.4%) the following mobile salmonella strains were isolated: two strains of S. virchow and Salmonella of subgroup II, four strains of S. typhimurium var. Copenhagen, seven strains of S. Livingstone, one S. enteritidis and one S. infantis The S. gallinarum was isolated from dead or sick chicken (46%), eggs (10.4%), rats Rattus norvegicus (14.3%) and mattresses 1.6%. The mobile salmonellae were isolated from feedstuffs (2%), flies (14.3%), rats (2.8%), feces (1%). From the present study, it seems that rats, chicken and eggs are important for the salmonella dissemination.  相似文献   

5.
Epidemiologically unrelated non-typhoid Salmonella isolates from humans (n = 56) and animal origin (n = 241, from faeces, carcasses and meat) in Vietnam were investigated. Salmonella Typhimurium, S. Anatum, S. Weltevreden, S. Emek, and S. Rissen were the most prevalent serovars. S. Typhimurium phage type 90 was predominant among S. Typhimurium isolates. The serotype and phage type distribution of the Salmonella isolates was different from that in Europe and America. Many sero- and phage types found in humans were also found in cattle, pigs, and poultry suggesting that food producing animals are an important source of human non-typhoid Salmonella infection in Vietnam.  相似文献   

6.
Prevalence and persistence of Salmonella in broiler chicken flocks.   总被引:2,自引:0,他引:2  
Cecal contents of 2,345 broiler chickens consisting of 28 flocks originated from 12 farms were examined for the prevalence of Salmonella to know the actual status of infection with Salmonella in the chicken flocks. Salmonella was isolated from 336 (14.3%) samples. From these isolates, eight serovars were identified. Of the 336 Salmonella isolates, 242 (72.0%) were serotyped as S. Blockley, 60 (17.9%) S. Hadar, 15 (4.5%) S. Bredeney, nine (2.7%) S. Schwarzengrund, four (1.2%) S. Anatum, three (0.9%) S. Enteritidis, two (0.6%) S. Ohio, and one (0.3%) S. Livingstone. The same serovars of Salmonella were repeatedly found in the chickens from the same farms. S. Typhimurium and S. Enteritidis were detected in pooled broken eggshell samples collected from the hatchery. Analysis of plasmid profiles revealed 11 patterns of S. Blockley and seven patterns of S. Hadar. Strains of the same plasmid profiles of S. Blockley were isolated repeatedly from the same farm over one year after the first isolation.  相似文献   

7.
Salmonella enterica serovar subsp. enterica Livingstone and serovar Cerro isolates from a commercial egg-producing farm, which had previously been untypeable by pulsed-field gel electrophoresis (PFGE) because of DNA degradation during the PFGE process, successfully gave banding patterns using electrophoresis buffer supplemented with 50 microM thiourea. By PFGE in the presence of thiourea, DNA degradation-sensitive S. enterica serovar Cerro isolates from the commercial egg-producing farm were found to be genetically unrelated to S. enterica serovar Cerro isolates that gave the patterns in the absence of thiourea. Forty-five of 50 (90%) S. enterica serovar Livingstone isolates from the farm showed arbitrarily designated XbaI-digested patterns X1 and X2 that were distinguished by one-band difference and had an identical BlnI-digested pattern. In one of the two layer houses in the farm, the numbers of isolates having the pattern X2 increased from 57% in 1997 to 89% in 1998, whereas virtually all the isolates obtained from the other house in the same period showed the profile X1. This suggests that strains having the pattern X2 might have an advantage to preferentially colonize in the former house.  相似文献   

8.
为了解广东省禽场和猪场沙门菌的血清型和耐药性情况,本研究2015年从广东省多个养殖场共采集样品126份,分离出沙门菌24株,分离率为19.04%。采用Kauffmann-White法、Kirby-Bauer法和PCR方法对分离株进行了血清型鉴定、药敏试验和Ⅰ类整合子检测。血清型鉴定结果显示,24株沙门菌共鉴定出4种血清型,分别是鼠伤寒沙门菌(14株)、印第安纳沙门菌(8株)、科瓦利斯沙门菌(1株)和阿尔巴尼沙门菌(1株)。药敏试验结果显示,分离株对四环素(83.33%)、氨苄西林(70.83%)、磺胺异恶唑(70.83%)、萘啶酸(66.67%)、复方新诺明(58.33%)、卡那霉素(54.17%)、阿米卡星(54.17%)、庆大霉素(50.00%)的耐药率较高,有54.17%(13/24)的菌株对8种及8种以上抗菌药物耐药。Ⅰ类整合子检测结果显示,Ⅰ类整合酶阳性率为29.17%(7/24),整合酶阳性菌株中仅有1株扩增到携带耐药基因aadA2的基因盒。上述结果表明,广东省禽场和猪场沙门菌分离率较高,耐药情况严重,菌株的耐药性与其血清型和Ⅰ类整合子的携带有一定的相关性。  相似文献   

9.
Salmonella pullorum is the cause of pullorum disease, which is characterized by white diarrhea and a high mortality rate in poultry. During the 1990s, the serologic "pullorum" test has occasionally failed to detect infected birds during the early stage of disease. To determine if any recent genetic changes have taken place in S. pullorum to account for poor seroconversion sometimes observed in infected flocks, S. pullorum from 1990s outbreaks and strains isolated prior to the 1980s were typed by random amplified polymorphic DNA (RAPD). Of 40 S. pullorum isolates typed by this method, eight distinct DNA patterns were identified with one of three RAPD polymerase chain reaction primers. Sixty-two percent of S. pullorum isolates shared the same RAPD DNA pattern, and a major proportion of these strains were from recent flock infections. The RAPD patterns for S. pullorum were clearly distinct from the avian Salmonella group B isolates included in this analysis. The distribution of Salmonella virulence genes among avian Salmonella isolates was also examined. Eighty-five percent of the S. pullorum isolates had both the virulence plasmid gene, spvB, and the invasion gene, invA, with the same percentage positive for the Salmonella enteriditis fimbrial gene, sef. However, significant variability was observed among S. pullorum in their ability to invade avian epithelial cells, despite the presence of the Salmonella invasion gene in these isolates.  相似文献   

10.
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 blaCTX-M-2, while the nine poultry isolates produced blaCTX-M-25 (4), blaSHV-2 (3), blaCTX-M-15 (1) and blaCTX-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.  相似文献   

11.
Salmonella isolates (n = 209) obtained from food animals and foods in Alberta during 1996 through 1999 were tested for sensitivity to 17 antimicrobials. Of the 3553 antimicrobial susceptibility tests on Salmonella isolates, 11.8% were positive for resistance. These isolates were commonly resistant to tetracycline (35.4%), streptomycin (32.5%), sulfamethoxazole (28.7%), ticarcillin (27.3%), and ampicillin (26.8%). Resistance to at least 1 antimicrobial was observed in 112 isolates (53.6%). Salmonella Typhimurium, S. Typhimurium var. Copenhagen, and S. Heidelberg were the most common serovars among isolates resistant to individual antimicrobials and multiple antimicrobials. The most common profile of multiple-antimicrobial resistance was that which included resistance to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, tetracycline, and ticarcillin. The proportions of isolates that were resistant to antimicrobials were greater among bovine isolates of Salmonella than among poultry isolates, and this difference was greater among isolates from veterinary diagnostic sources than among those from monitoring sources.  相似文献   

12.
Cloacal and pharyngeal swabs from 100 tree-nesting Double-crested cormorant (DCC) chicks were examined by culture for commensal and potentially pathogenic bacteria. No Salmonella or Erysipelothrix were isolated from the cloacal swabs. Twenty-two cloacal swabs were positive for Campylobacter, of which 14 were C. jejuni, C. coli, and 1 C. lari. None belonged to common serotypes isolated from humans or animals in recent years in Canada. Tests for antimicrobial drug resistance among 187 commensal Escherichia coli isolates from the cloacal swabs indicated that < or =5% were resistant to any of the 12 antibiotics tested. This contrasts with the frequently high resistance rates among E. coli isolates from poultry. Pharyngeal swabs from DCC were negative for Pasteurella multocida. Culture of cloacal swabs from 100 ground-nesting DCC chicks resulted in the recovery of 19 Salmonella isolates, all of which were S. enterica serotype Typhimurium. None of these isolates were resistant to any of the 12 antibiotics tested. Altogether, these findings suggest that DCC from this region are not being colonized with commensal or potentially pathogenic enteric bacteria from agricultural or human sources and that enteric bacteria isolated from these birds are unlikely to contribute to a gene pool of antimicrobial drug resistance.  相似文献   

13.
Following the introduction of a national abattoir-based monitoring programme for Salmonella in pigs, advisory visits were made to pig farms in England and Wales with high Salmonella seroprevalence assessed by muscle tissue fluid (meat juice) ELISA. Samples (n = 15 790), including pooled pen floor faeces (n = 12 136), were collected for Salmonella culture from 296 farms, between October 2003 and February 2008. Salmonella was isolated from 4489 (28%) of all samples collected, including 3301 (27%) of pooled pen floor faecal samples, from 270 (91%) of farms visited. Salmonella Typhimurium and S. Derby were the most prevalent serovars, representing 64% and 16% of isolates serotyped, respectively. The main phage types of S. Typhimurium identified were U288 and DT193. Antimicrobial resistance (AMR) was seen in 92% of isolates tested, with the highest frequencies of resistance occurring to tetracyclines (T), sulphonamide compounds (SU), ampicillin (AM), sulphamethoxazole/trimethoprim (SXT), streptomycin (S) and chloramphenicol (C). Fifty-nine AMR patterns were observed, the most frequent of these being T, AM, SXT, C, S, SU, seen in 35% of isolates tested. Multi-drug resistance was commonly found, with 67% of isolates submitted for AMR testing showing resistance to between four and nine antimicrobials.  相似文献   

14.
A total of 39 Salmonella cultures isolated from raw minced beef and chicken (gizzard, liver, and heart) samples in Addis Ababa were examined for susceptibility to a group of 10 selected antimicrobials. 34 isolates (87.2%) were resistant to one or more antibiotics. The antibiotics to which isolated Salmonella strains were most often fully resistant included nitrofurantoin (48.7%), furazolidone (48.7%) and streptomycin (46.2%). Only 4 antimicrobials (gentamycin, kanamycin, rifampicin and sulphamethoxazole-trimethoprim) were effective against all Salmonella isolates with the exception of 2 which were intermediate in resistance to kanamycin (1) and sulphamethoxazole-trimethoprim (1). 77.8% of the S. Enteritidis strains showed multiple resistance to up to four antibiotics followed by S. Typhimurium (60.0%) and S. Dublin (33.3%). The high level of antibiotic resistance of foodborne Salmonella isolates in the study area is an indication of indiscriminate and continuous use of subtherapeutic doses of antibiotics in animals.  相似文献   

15.
An epidemiological investigation of a calf rearing premises and a closely associated dairy herd was carried out after the isolation of Salmonella enterica serovar Paratyphi B variant Java phage type 3b variant 2 from clinically diseased calves on the premises. The isolate was resistant to ampicillin, chloramphenicol, streptomycin, sulphonamides, tetracyclines, trimethoprim and cefoperazone. The organism was widespread on the calf unit and was also recovered from the dairy premises, mainly from groups of weaned calves. The investigation was extended to 10 epidemiologically linked farms but no S Java was isolated from any of the 40 to 60 samples collected from each premises. Molecular studies showed that the S Java isolates were genetically most similar to isolates from cases of human disease associated with ornamental fish tanks or feed. Long PCR and resistance gene profiling identified a resistance island which was indistinguishable from the human 'fish tank' strain of S Java and animal and human epidemic strains of S Typhimurium DT104. The isolates were clearly distinguished from multi-resistant S Java strains commonly associated with continental poultry. This is the first report of S Java with this resistance pattern in Great Britain.  相似文献   

16.
This paper reports the susceptibility to the quinolone nalidixic acid and the fluoroquinolone ciprofloxacin of 14,514 strains of Salmonella isolated in Germany from poultry, cattle and pigs between 1998 and 2001. Quinolone-resistant salmonellae were most frequently isolated from poultry, with a prevalence of 10.2 to 16.8 per cent. Poultry-associated serotypes, such as Salmonella Paratyphi B (d-tartrate positive), Salmonella Hadar and Salmonella Virchow, had the highest prevalence of quinolone resistance, ranging between 35 and 74 per cent. All the nalidixic acid-resistant strains also had a reduced susceptibility to ciprofloxacin, with minimum inhibitory concentrations (MICS) of 0.125 to 2 microg/ml. A comparison of the MICS for ciprofloxacin of the strains of these poultry-associated serotypes and Salmonella Enteritidis phage type 4 isolated in 1998/99 and 2000/01 indicated that there had been a shift towards higher MIC values of up to 2 microg/ml. The quinolone resistance-determining region (QRDR) of the gyrA gene and the homologue region of the parC gene of 31 selected strains were sequenced. Several different amino acid changes were observed in gyrA of the quinolone-resistant isolates at positions 83 and 87, but no substitutions were observed in parC.  相似文献   

17.
In a representative study, 380 manure samples of pig farms distributed all over Bavaria (Germany) were screened for the presence of Salmonella spp. at the time of manure application to soil using methods adapted to DIN EN ISO 6579. The isolates were tested according to DIN 58940 for their susceptibility towards 26 antimicrobial substances - such substances partly administered in animals, but mainly used in human therapy. Six out of 380 manure samples and, in addition, the only separated liquid manure sample examined, contained Salmonella isolates. Serotypes represented S. Typhimurium (n = 5), S. Derby (n = 1) and S. Infantis/S. Serogroup C1-(6,7:r:-)-form (each n = 1). Within the serovar S. Typhimurium, the most common phage type was DT104 (n = 3). All Salmonella isolates originated from 'big' farms (>30/45 sows on combined/breeding farms or >220 fattening pigs). Four out of six manure samples contained resistant isolates; all resistant Salmonellae were multi-resistant. Two out of three DT104-isolates showed the typical penta-resistance pattern often found in S. Typhimurium DT104, which was, furthermore, supplemented by other resistances. One Escherichia coli isolated together with a phage type DT104 S. Typhimurium also expressed the same penta-resistance pattern.  相似文献   

18.
After importing of breeder lines for laying flocks from Canada into the former GDR in 1966 the egg industry in this country was completely isolated from that in Western Germany or other Western European countries until opening the border in Germany in 1989. Because of this isolation from other countries, an analysis of the clonal diversity of Salmonella (S.) Enteritidis isolates originated from humans, chickens and food in the former GDR during the 1980s would provide a unique opportunity to obtain new insight into factors that may have triggered the S. Enteritidis epidemic. While isolates had previously been typed by the phage typing scheme of Lalko and Laszlo we applied for the first time the extended phage typing scheme by Ward for the retrospective analysis of the S. Enteritidis strains. Furthermore, isolates of phage type (PT) 4/6 (Ward / Lalko and Laszlo) from different livestocks were investigated by ribotyping. Although in total the PT4/6 dominated between 1986 and 1989 in poultry, other phage types have prevailed in the early 1980s and represented a considerable fraction of isolates until 1989. For instance, PT8/7 was isolated from one large layer farm (district Halle) from 1988 until 1989. During that time in another farm (district Cottbus) only PT8/7 was detected too. PT4/6 was isolated from neither of these two laying hen farms. The strains of PT4/6 could be distinguished by ribotyping in 19 different subtypes. The strains from the northern farms were distinct from those isolated in the southern regions. As farms which were harbouring either PT4/6 or PT8/7 had obtained laying hens from the same sources (breeder lines in Deersheim and Spreenhagen) it is highly probable that S. Enteritidis infection was acquired from the environment at each individual farm. This conclusion is also supported by the presence of different PT4/6 ribotypes in different farms. The presence of different phage types or PT4/6 ribotypes at different farms of laying hens suggests that in each case the S. Enteritidis strains present in the environment were able to enter chicken flocks.  相似文献   

19.
The aim of the present study was to contribute to the knowledge on extended-spectrum beta-lactamases (ESBL's), AmpC beta-lactamases and integrons in Enterobacteriaceae isolated from horses, which is still limited. The susceptibility of 1581 clinical isolates from animals to ceftiofur was tested. Most of these isolates (n=1347) originated from horses. Seven ceftiofur-resistant equine isolates (four Escherichia coli and three Klebsiella pneumoniae) were identified and all seven were multidrug-resistant. These isolates were further studied for the presence of ESBL's, AmpC beta-lactamases and class 1 integrons. The potential for the horizontal transfer of resistance genes among these clinical isolates was also studied. ESBL-type resistance genes were found in five isolates, AmpC-type genes in one isolates and integrons in six isolates. Nucleotide sequence analysis revealed that the isolates carried the bla(CTX-M-1), bla(CMY-2), bla(TEM-1) and/or bla(SHV-1) genes. This is the first report describing the in vitro conjugal transfer of the bla(CTX-M-1) genes from a clinical E. coli isolate to Salmonella isolates. Gene cassettes encoding resistance to aminoglycosides (aadA1, aadA2 and aadA5), and trimethoprim (dfrA1, drfA12 and dfrA17) were found on the integrons present in the isolates. The cassette arrays of the dfrA17-aadA5 and dfrA1-aadA1 genes in the two integrons of a single E. coli isolate have not yet been described before. To our knowledge this is the first report on ESBL's and AmpC beta-lactamases in equine E. coli and Klebsiella isolates.  相似文献   

20.
Avian paramyxoviruses (APMVs) belonging to the subfamily Avulavirinae within the family Paramyxoviridae. APMVs consist of twenty-two known species and are constantly isolated from a wide variety of avian species around the world. In this study, the APMV isolates obtained from wild birds and domestic poultry during 2009–2020 in Taiwan were genetically characterized by phylogenetic analysis of their complete fusion protein gene or full-length genome. As a result, 57 APMV isolates belonging to seven different species were obtained during this period and subsequently identified as APMV-1 (n=17), APMV-2 (n=1), APMV-4 (n=25), APMV-6 (n=8), APMV-12 (n=2), APMV-21 (n=2) and APMV-22 (n=2). Sanger sequencing was performed to provide 22 full-length genome sequences and 35 complete fusion protein gene sequences for the APMV isolates. Phylogenetic analysis showed that the recovered viruses were closely related to Eurasian strains, except five class I APMV-1 and four APMV-4 isolates were related to North America strains. Our findings provided more evidence for the intercontinental transmission of APMVs between Eurasia and North America by wild birds. In addition, according to the criteria of the classification system based on complete fusion protein gene sequences, three novel genotypes within APMV-2, APMV-12, and APMV-22 were identified. Together, this investigation provided a broader perspective on the genetic diversity, evolution, and distribution of APMVs in multiple avian host species sampled in Taiwan.  相似文献   

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