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1.
We investigated the antimicrobial susceptibilities and molecular epidemiology of 200 strains of Salmonella enterica serotype typhimurium isolated from 1989 to 1996 in Hong Kong. Only 22% of strains were susceptible to all 19 antibiotics tested but all were susceptible to second- and third-generation cephalosporins. Up to 9% of strains were resistant to 0.12 mg/l concentrations of ciprofloxacin or ofloxacin but none were resistant to 1 or 2 mg/l concentrations of these 2 drugs, respectively. The isolates were grouped into 15 types by ribotyping with restriction endonuclease EcoRI and into 53 types by pulsed-field gel electrophoresis of XbaI-restricted DNA fragments. When DNA fragments of the ribotypes and pulsotypes were pooled and analyzed 87 types resulted, 76 (87%) of which were of > 90% similarity and were grouped into 15 clusters. About 60% of the isolates belonged to 3 clusters, which probably represented 3 clones endemic in the community. The rest of the isolates were of a large variety of types or clusters. For epidemiological purposes analysis of pooled results from different molecular techniques would be more discriminative than results from individual techniques alone.  相似文献   

2.
目的 了解贵州省2017-2018年非伤寒沙门菌(NTS)的血清型分布、耐药情况与脉冲凝胶电泳(PFGE)分子分型特征.方法 对分离自贵州省临床病例的191株非伤寒沙门菌菌株进行生化鉴定、血清型分型,微量肉汤稀释法测定16种抗生素的最小抑菌浓度,PFGE进行分子分型分析.结果 191株非伤寒沙门菌分出18种血清型,鼠伤...  相似文献   

3.
目的分析2014-2020年宁夏食品及病例来源沙门菌耐药情况、流行优势血清型及PFGE型别。方法对2014-2020年各类食品及临床病例中分离培养的188株沙门菌进行血清分型、脉冲场凝胶电泳(PFGE)分子分型和肉汤稀释法药物敏感性实验。结果肠炎沙门菌在食品及病例中均为优势血清型,病例来源分离76株,占49.35%(76/154),食品来源分离18株,占52.94%(18/34),总构成比为50%(94/188)。188株不同来源沙门菌有182株出现不同程度的耐药,176株为多重耐药菌株。其中耐2~4种抗生素101株(55.49%),耐5~8种抗生素52株(28.57%),耐9~12种抗生素23株(6.59%)。将所有分离株经Xbal酶切,脉冲场凝胶电泳后,共获得93条PFGE带型,相似度为42.1%~97.1%,优势带型为NXSM0065型,其次为NXSM0074和NXSM0069,共41株,占所有分离株的21.81%。结论宁夏地区沙门菌流行优势血清型为肠炎沙门菌,病例及食品来源分离株耐药状况普遍较为严重,不同来源,同一血清型PFGE带型同源性较高,且与耐药谱未体现出明显的关联性。  相似文献   

4.
BACKGROUND: Penicillin-nonsusceptible Streptococcus pneumoniae isolates are confined mainly to a few serogroups. Capsular transformation may serve as a mechanism for spreading antibiotic resistance to new serotypes. METHODS: Antibiogram and molecular typing, by pulsed-field gel electrophoresis (PFGE), were performed on 46 nasopharyngeal and middle ear fluid (MEF) isolates expressing serotype 11A, 45 MEF isolates expressing serotype 15B/C (recovered during 1998-2003 from Israeli children <5 years old), and 57 MEF isolates expressing serotype 19F (recovered during 1998-2001 from Costa Rican children <7.5 years old). RESULTS: PFGE patterns showed that 49 (86%) of 57 serotype 19F isolates and 19 (41%) of 46 serotype 15B/C isolates were closely related. The vast majority of these isolates (80% of serotype 19F and 100% of serotype 15B/C isolates) were nonsusceptible to penicillin. Multilocus sequence typing (MLST) data show that the serotype 15B/C isolates belonged to the ST346 cluster, whereas the serotype 19F isolates were a single-locus variant of ST346. For serotype 11A isolates, PFGE patterns and MLST analysis showed that 8 (80%) of the 10 penicillin-nonsusceptible isolates belonged to a single clone--namely, ST156--which was identical to the international Spain9V-3 clone. CONCLUSIONS: Penicillin-nonsusceptible pneumococcal clones of serotypes not related to those included in the 11-valent conjugate vaccines may derive from capsular transformation of vaccine-related serotypes. Of particular concern was the detection of serotype 11A variants of the successful international Spain9V-3 clone. This phenomenon, although seemingly rare at present, can have implications for the long-term effectiveness of the conjugate vaccines.  相似文献   

5.
In this study, antimicrobial susceptibility test and genetic typing were used to characterize 15 Salmonella enterica serotype Typhi (S. Typhi) isolates recovered from sporadic cases of typhoid fever in Tehran, Iran during 2004. Antimicrobial susceptibility test showed that all isolates were susceptible to 20 antimicrobials examined in this study. Analysis of insertion elements showed that 2 IS200 types with 10 and 11 copies were present. 11 of the 15 isolates were found to possess 10 IS200 elements residing on fragments from 23 to 2.3 kb. Comparison of the RiboPrinter (automated ribotyping) patterns of S. Typhi showed that 60% (9/15) of the isolates belonged to a single ribotype. PCR based random amplified polymorphic DNA analysis (RAPD) and enterobacterial repetitive intergenic consensus (ERIC) and pulsed-field gel electrophresis (PFGE) were also performed. ERIC and RAPD-PCR method showed 2 and 3 genotyping patterns amongst the isolates, respectively. The PFGE typing was carried out by using XbaI restriction enzyme, and 7 restriction patterns were observed. Overall, the molecular typing methods applied in this study showed that the isolated S. Typhi populations were highly polyclonal as shown by PFGE.  相似文献   

6.
In a 5-year prospective study in a Hong Kong teaching hospital there were 344 clinically significant episodes of paediatric septicaemia. Many of the microbiological and clinical features were similar to those reported in Japanese and Western studies but there were some important differences. Half of the episodes (or 70% if neonatal infections are excluded) were community-acquired. The commonest organisms found were Salmonella spp (15% of all and 27% of community-acquired infections); this was related to the high local incidence of salmonellosis and typhoid fever. Salmonella typhi, which was responsible for one-third of the salmonella septicaemias, was usually seen in school-age children, while non-typhoid salmonellae were common in infants. Methicillin-resistant Staphylococcus aureus, which are now endemic in Hong Kong hospitals, was a common cause of hospital-acquired septicaemia. Pneumococcal septicaemia accounted for 22% of episodes in infants and pre-school children, but Haemophilus influenzae was uncommon (2% of all episodes) and there was no case of meningococcal septicaemia. The rarity of invasive infection with H. influenzae and Neisseria meningitidis in Hong Kong children is unexplained.  相似文献   

7.
目的分析2012-2016年深圳地区感染性腹泻沙门菌耐药状况及分子型别特征,为沙门菌感染防控提供科学依据。方法收集深圳地区四家医院的137株沙门菌,传统血清学方法鉴定沙门菌血清型,微量肉汤稀释法测定菌株药物敏感性,脉冲场凝胶电泳(PFGE)对鼠伤寒沙门菌和肠炎沙门菌作分子同源性分析。结果 137株沙门菌可分为30种菌型,鼠伤寒沙门菌和肠炎沙门菌是本地优势菌型。菌株对链霉素、氨苄西林、阿莫西林/克拉维酸钾耐药最为严重,对青霉素类、头孢类、氨基糖苷类、大环内酯类抗生素的耐药呈逐年增高的趋势。49株鼠伤寒沙门菌经脉冲场凝胶电泳可获得38种带型,相似度65.5%~100%,TY18为优势带型;27株肠炎沙门菌经脉冲场凝胶电泳可获得9种带型,相似度61.8%~100%,EN7为优势带型。结论感染性腹泻来源沙门菌耐药状况比较严重,菌株PFGE带型多样化,呈高度散发,部分带型与其耐药谱之间具有一定的聚集与关联性。  相似文献   

8.
Methicillin resistant Staphylococcus aureus (MRSA) is an important hospital and community-acquired pathogen. Rapid and reliable epidemiologic typing is necessary for controlling the spread of MRSA outbreak. The objective of this study was to compare the phenotyping with the genotyping method to differentiate MRSA isolates obtained from the two hospitals in Thailand (central and northeastern). Seventy-four MRSA isolates were randomly collected and confirmed by the presence of mecA gene. Antibiogram, phage typing and enterotoxin production were used for the phenotyping analysis. Pulsed-field gel electrophoresis (PFGE) with Smal digestion of chromosomal DNA was used for the genotyping analysis. We found 17 distinct profiles by the 3 phenotypic typing methods and 18 PFGE types designated as 5 major types (A-E) and 13 subtypes. The most frequent PFGE types and their related subtypes found in both hospitals were A and C, comprising 54 and 27%, respectively. The antibiogram could differentiate 6 different types. All isolates were resistant to the majority of antimicrobial agents tested, but were susceptible to vancomycin and fosfomycin. Ten (13.5%) MRSA isolates produced enterotoxin A. Nontypable phage and phage type 77 were found predominantly in MRSA isolated from the northeast and central hospital, respectively. A significant correlation was found between the phenotyping and the genotyping methods and there was a good correlation between antibiogram and PFGE. Antibiogram typing alone can be used as a useful epidemiological marker for practical purposes. PFGE types A and C were the common endemic MRSA clones in both hospitals in Thailand.  相似文献   

9.
The present study was undertaken to identify and characterize integrons and integrated resistance gene cassettes among multidrug resistant (MDR) Salmonella isolates from slaughter animals and food products of animal origin in Ethiopia. A total of 98 epidemiologically unrelated Salmonella isolates comprising 13 serovars were characterized using serotyping, phage typing, antimicrobial resistance testing and the pulsed-field gel electrophoresis (PFGE) method. Integron-PCR was used to detect the presence of class 1 and class 2 integrons in the MDR strains. The associated individual resistance gene cassettes were identified using specific PCRs and DNA sequencing. The location of the integrons was determined by Southern blot hybridization analysis. Among the Salmonella serovars, a high level of antimicrobial resistance was found to streptomycin (82.6%), tetracycline (75.5%), sulfamethoxazole (60.2%), spectinomycin (53.1%), ampicillin (42.8%), nalidixic acid (34.7%), nitrofurantoin (30.6%), trimethoprim (27.5%), gentamicin (20.4%) and ciprofloxacin (19.4%). Class 1 integrons were detected in 53.1% of the MDR isolates comprising serovars Anatum, Braenderup, Kentucky, Saintpaul and Typhimurium. Of the class 1 integron positive isolates 61.5% harboured the integron-associated gene cassettes: aadA2, aadA2+bla(PSE-1), dfrA1-aadA1 and dfrA12-orf-aadA2 (amplicon sizes 1000 bp, 1000+1200 bp, 1600 bp and 1900 bp, respectively). The chromosomally located aadA2 and aadA2+bla(PSE-1) resistance gene cassettes occurred exclusively in S. Typhimurium DT104 isolates, the other cassettes were found on large plasmids in several serovars. An aacCA5-aadA7 gene cassette array (amplicon size 1600 bp) was exclusively found in all MDR S. Kentucky strains of R type Str/SpeSmxGenNalAmpTetCipCef and this integron was shown to be chromosomally located. Results of the present study indicate that class 1 integrons carrying gene cassettes, which confer resistance to different classes of antimicrobials such as aminoglycosides, beta-lactams and trimethoprim are widespread among the MDR Salmonella serovars isolated from slaughter animals and food products of animal origin in Ethiopia indicating the important role of these genetic elements in the dissemination of multidrug resistance.  相似文献   

10.
Molecular typing was performed to reveal the genetic diversity among Staphylococcus aureus strains causing deep-seated versus superficial staphylococcal infections. Pulsed-field gel electrophoresis with cluster analysis, plasmid and antimicrobial susceptibility profiling of 50 S. aureus strains collected from these 2 groups of patients were undertaken. A total of 19 (designated A through S) distinct genotypes were identified by PFGE of Sma I-digested genomic DNA. The most prevalent PFGE type was L, which accounted for 30% of isolates and was detected among superficial isolates only. The second most prevalent PFGE type, type A (18%), was predominant among deep-seated isolates. Remaining PFGE types varied in distribution between the 2 groups. Plasmid profile analysis revealed that deep isolates harbour plasmids more frequently (comprising 64% of isolates) than superficial isolates (4%) and showed 10 and 2 distinct patterns, respectively, with pattern 1 being the dominant among deep isolates. Antimicrobial susceptibility data suggested an increased prevalence of antibiotic resistance among deep isolates with the majority (40%) exhibiting identical antibiograms compared to superficial isolates. No resistance was detected against clindamycin and vancomycin. The results of our study indicate a previously unrecognized dichotomy of S. aureus strains, causing deep-seated and superficial infections.  相似文献   

11.
Antimicrobial susceptibility, pneumococcal surface protein A (PspA) serotyping, and pulsed-field gel electrophoresis (PFGE) were used to evaluate clonal relatedness among 66 invasive isolates of Streptococcus pneumoniae serotype 6B collected during 1982-1996 from patients in Alaska. Thirty-seven (56%) of the isolates had penicillin minimal inhibitory concentration values >/=0.125 microgram/mL and were resistant to at least 1 other antibiotic. Fourteen PspA serotypes were observed; PspA 16 was the most common (35%). Forty-five (68%) of the 66 isolates shared common and highly related PFGE patterns using 3 enzymes. Twenty-six (58%) of the isolates with common PFGE patterns were from Native Alaskan children 相似文献   

12.
摘要:【目的】了解郑州市感染性腹泻病人中沙门病原菌血清型分布和耐药谱,为沙门菌防治提供基础数据。【方法】从2006-2011年腹泻病监测点感染性腹泻病例的粪便标本中进行沙门菌分离培养、血清学分型及药敏试验,用WHONET5.4软件分析药敏试验结果。【结果】2006-2011年共采集的3266份腹泻病人标本中共检出196株沙门菌,检出率为6.0%,分布于10个血清群,37个血清型;以B群和D1群为主,各占33.67%(66/196)和32.14%(63/196);血清型以肠炎沙门菌和鼠伤寒沙门菌为主,各占29.59%(58株)和19.90%(39株)。药敏试验结果提示对氨苄西林、萘啶酸、复方新诺明和四环素的耐药率分别达到44.90%、42.34%、34.18%和32.14%。【结论】沙门菌血清型和耐药谱监测对感染性腹泻疫情防控意义重大。  相似文献   

13.
Altogether 403 Haemophilus spp. were isolated in seven hospital laboratories in Hong Kong during June 1986, mostly from sputum. Of these 73% were Haemophilus influenzae and 27% Haemophilus parainfluenzae. All the isolates of H. influenzae were non-capsulated; Haemophilus spp. were not isolated from blood or cerebrospinal fluid (CSF) during the period of the study. Antimicrobial resistance, including multiple resistance, was common. Of all the strains of H. influenzae, 20% were resistant to 1 mg/l ampicillin, (all except one by production of TEM-1 beta-lactamase), 65% were resistant to 0.5 mg/l erythromycin, 25% to 1 mg/l tetracycline, 14% to 1 mg/l chloramphenicol (mediated by the production of a chloramphenicol-destroying enzyme) and less than 1% to 8 mg/l cefaclor and 0.5 mg/l trimethoprim. All isolates were susceptible to cephamandole and cefuroxime. Haemophilus parainfluenzae showed similar susceptibilities, except that a greater proportion of strains was sensitive to erythromycin and chloramphenicol. Only 50% of the ampicillin-resistant strains of H. influenzae and H. parainfluenzae contained detectable plasmids of 2-55 Mdal arranged in six to nine different plasmid profiles. Resistance to ampicillin and chloramphenicol has increased markedly in isolates of H. influenzae in Hong Kong over the last 5 years. This resistance may be associated with transposable genes.  相似文献   

14.
目的了解上世纪90年代以来我国部分地区禽源大肠杆菌和沙门菌分离株对1-4代喹诺酮类药物耐药情况。方法血清型采用常规的凝集试验进行测定;药敏纸片试验采用CLSI(clinical and laboratory standards institute)推荐的K-B药敏纸片法。结果344株禽源大肠杆菌分离株覆盖了27个血清型,其中O78、O2、O1和O18血清型菌株分别有141、47、27和22株,共237株,占定型菌株的68.90%;224株禽源沙门菌经血清型鉴定均为鸡白痢沙门菌。1993-1999年禽源大肠杆菌分离株仅对萘啶酸的耐药率超过60%(62.43%,113/181);2000-2008年禽源大肠杆菌分离株对1-3代9种喹诺酮类药物的耐药率均超过60%;禽源沙门菌从2000年起开始出现喹诺酮类耐药菌株,2000-2008年分离到的沙门菌对萘啶酸的耐药率达到了83.74%,但对其它喹诺酮类抗生素的耐药率相对较低。结论近20年来,我国禽源大肠杆菌和沙门菌对喹诺酮类药物的耐药性不断上升,10种喹诺酮类药物之间存在着不同程度的交叉耐药性,且禽源大肠杆菌比沙门菌对喹诺酮类药物的耐药性更为严重,交叉耐药情况亦更为复杂。  相似文献   

15.
目的 了解马鞍山地区腹泻监测人群非伤寒沙门菌的感染状况、血清学分布、分子分型与耐药性等特征。方法 对2010-2018年腹泻患者中分离的非伤寒沙门菌进行血清学分型、脉冲场凝胶电泳(PFGE)和药物敏感性试验。结果 从2 998例腹泻患者中检出非伤寒沙门菌腹泻263例(8.8%),其中2例为2种非伤寒沙门菌混合感染;6-7月份非伤寒沙门菌感染率较高,05岁年龄组感染率最高(15.9%)(χ2=72.98,P<0.001);265株非伤寒沙门菌分为36个血清型,优势血清型为阿贡纳沙门菌、肠炎沙门菌和鼠伤寒沙门菌;阿贡纳沙门菌的PFGE带型分布较集中,有菌株成簇存在的现象;测试菌株总耐药率为95.6%(66/69),多重耐药率为82.6%(57/69);测试菌株对AMP(79.7%)、STR(75.3%)和Sul(66.6%)耐药率较高,对AMI和AZI 完全敏感;发现2株ESBLs的菌株,均为多重耐药菌株;鼠伤寒沙门菌和肠炎沙门菌对不同药物的敏感性有所不同,前者对喹诺酮类药物较敏感,而后者对四环素类药物较敏感。结论 马鞍山地区优势血清型为阿贡纳沙门菌,与其他地区不同。阿贡纳沙门菌有成簇存在的情况,提示有既往暴发的可能。总耐药及多重耐药现象严重,应谨慎用药并加强对病例的耐药监测。  相似文献   

16.
We investigated the serotypes, distributions, and antimicrobial resistance of Campylobacter jejuni isolates from humans and animals as a source of infection in poultry between 2002 and 2003. A total of 50 C. jejuni isolates from humans and 29 C. jejuni isolates from poultry were studied for serotype using the Penner serotyping scheme and the drug susceptibilities of the isolates which were determined for 7 antimicrobial drugs using the disk diffusion method. Serotype B (10%), serotype E (8%) and serotype R (8%) were found in humans isolates, while serotype A (27%) was most freguently isolated from poultry, followed by serotype K (21%) and serotype C (13%). Resistance in human isolates to cephalothin was high (100%). Resistance to trimethoprim/sulfamethoxazole, ciprofloxacin, and nalidixic acid were observed in 90, 82 and 78% of isolates, respectively. Most of the isolates (88%) were susceptible to erythromycin. High levels of resistance to drugs (ciprofloxacin and nalidixic acid) were observed in the isolates from poultry. These results indicate the importance of poultry as a reservoir of C. jejuni infection in Thailand is limited. In addition, a high proportion of the isolates were resistant to antimicrobial drugs, particularly the quinolone group.  相似文献   

17.
A total of 138 isolates of S. Typhimurium and S. 4,[5],12:i:- from humans and swine in Thailand during 2003-2006, were evaluated for antimicrobial sensitivity by the disk diffusion method against 10 antimicrobial drugs and pulsed-field gel electrophoresis (PFGE) with endonuclease Xbal to investigate the epidemiological relationship among isolates. It was found that all isolates were classified into 27 antimicrobial resistance patterns, and 80% of S. Typhimurium and 95.4% of S. 4,[5],12:i:- isolates were resistant to three or more antimicrobial agents. By PFGE testing, the 84 PFGE patterns were categorized into A to Z patterns. Eighty percent of S. Typhimurium and 71.3% of S. 4,[5],12:i:- isolates in 7 major PFGE patterns had close clonal relationships (_85% similarity). Our studies indicate the spread of genetically identical clones of S. Typhimurium and S. 4,[5],12:i:- in humans and swine in Thailand.  相似文献   

18.
In the present study, a total of 455 enterococcal isolates, recovered from patients living in the city of Porto Alegre, State of Rio Grande do Sul, Brazil, during the period from July 1996 to June 1997, were identified to the species level by conventional biochemical and microbiological tests, and assayed for their susceptibilities to antimicrobial agents. The genetic diversity of antimicrobial resistant strains was evaluated by pulsed-field gel electrophoresis (PFGE) analysis of SmaI restricted chromosomal DNA. The most frequent species was Enterococcus faecalis (92.8%). Other species identified were: E. faecium (2.9%), E. gallinarum (1.5%), E. avium (1.1%), E. hirae (0.7%), E. casseliflavus (0.4%), E. durans (0.4%) and E. raffinosus (0.2%). The overall prevalence of isolates with high-level resistance (HLR) to aminoglycosides was 37.8%. HLR to gentamicin was found in 24.8%. No strains with acquired resistance to vancomycin were found. PFGE analysis showed the predominance of clonal group A, comprising strains isolated from different clinical specimens obtained from patients in three hospitals. These results suggest intra and inter-hospital dissemination of one predominant clonal group of E. faecalis isolates with HLR to gentamicin in the hospitals included in this study.  相似文献   

19.
This study examined the prevalence of antibiotic-resistant clones that belong to serotypes not included in the pneumococcal conjugate vaccines and that cause a significant percentage of acute otitis media (AOM) in children in southern Israel. During 1998-2001, 2467 pneumococcal isolates, obtained from middle-ear fluid of children <3 years old with AOM, were characterized by antimicrobial susceptibility testing, serotype testing, and pulsed-field gel electrophoresis. Non-vaccine type (NVT) strains constituted 477 (19%) of the 2467 isolates, of which 173 (36%) belonged to only 4 serotypes: 35B, 33F, 21, and 15B/C. For serotype 35B, 47 (96%) of 49 strains were penicillin nonsusceptible, and 93% constituted a single clone; for serotype 33F, 31 (82%) of 38 strains were penicillin nonsusceptible, and 95% constituted a single clone; for serotype 21, 38 (93%) of 41 strains were penicillin nonsusceptible, and 93% constituted a single clone; for serotype 15B/C, 22 (49%) of 45 strains were penicillin nonsusceptible, and 42% constituted a single clone. Two of these clones have not been described elsewhere. The high prevalence of NVT clones should increase the awareness of the potential for replacement of the vaccine strains with these NVT antibiotic-resistant strains.  相似文献   

20.
目的分析无锡市腹泻人群中分离的沙门菌的流行特征;同时比较主要血清型菌株间的脉冲场凝胶电泳(PFGE)带型差异,为沙门菌感染的防控提供实验数据。方法收集2015年无锡市腹泻病人的粪便标本,分别进行沙门菌的分离鉴定、药敏试验、血清型分型以及PFGE分型分析。结果 756份粪便标本中共分离到32株沙门菌,阳性率为4.23%;检出时间主要集中在5~10月份,感染人群以老年人为主。药敏试验说明无锡地区的沙门菌对氨苄西林的耐药率最高,达56.25%;对环丙沙星和头孢他啶的耐药率最低,均为6.25%。32株沙门菌共鉴定出11种血清型,以肠炎沙门菌和鼠伤寒沙门菌为主,分别占31.25%和21.88%。对这2种血清型的沙门菌进行PFGE分析,显示肠炎沙门菌所有带型的相似度均在85%以上,鼠伤寒沙门菌的带型各不相同。结论无锡市沙门菌的感染具有明显季节和年龄分布差异性,流行的优势血清型为肠炎沙门菌。无锡市需同时加强对食品和环境中沙门菌的监测。  相似文献   

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