Campylobacter antimicrobial resistance in Peru: a ten-year observational study

ABSTRACT: BACKGROUND: : Campylobacter jejuni and Campylobacter coli are food-borne pathogens of great importance and feature prominently in the etiology of developing world enteritis and travellers' diarrhoea. Increasing antimicrobial resistant Campylobacter prevalence has been described globally, yet data from Peru is limited. Our objective was to describe the prevalence trends of fluoroquinolone and macrolide-resistant C. jejuni and C. coli stool isolates from three regions in Peru over a ten-year period. METHOD: S: Surveillance for enteric pathogens was conducted in Lima, Iquitos and Cusco between 2001 and 2010. Campylobacter stool isolates were tested for susceptibilities to ciprofloxacin, azithromycin and erythromycin. Susceptibilities were reviewed for 4652 isolates from Lima (n = 3419), Iquitos (n = 625) and Cusco (n=608). RESULTS: : Comparing the study periods of 2001-2005 and 2006-2010, prevalence of ciprofloxacin-resistant C.jejuni isolates rose in the study areas of Lima (73.1% to 89.8%, p < 0.001) and Iquitos (24.1% to 48.9%, p < 0.001). Ciprofloxacin-resistant C.coli rates also increased in Lima (48.1% to 87.4%, p < 0.001) and Cusco (10.0% to 65.9%, p = 0.005). Small but significant increases in azithromycin-resistant and erythromycin-resistant C. jejuni prevalence were noted in Iquitos (2.2% to 14.9%, p < 0.001; 3.2% to 14.9%, p = 0.002), and erythromycin-resistant C.coli rates increased in Lima (0.0% to 5.3%, p = 0.038). The prevalence of C.jejuni isolates resistant to both ciprofloxacin and azithromycin increased in Iquitos (0.3% to 14.9%, p < 0.001) and Lima (0.3% to 1.6%, p = 0.011), and prevalence of C.jejuni isolates resistant to both ciprofloxacin and erythromycin rose in Iquitos (0.0% to 14.9%, p < 0.001). Ciprofloxacin and erythromycin resistant C.coli prevalence increased in Lima (0.0% to 5.3%, p = 0.034). CONCLUSIONS: : These results have implications for the empirical management of enterocolitis in Peru. Ongoing surveillance is essential to guide appropriate antimicrobial use in this setting. Local epidemiological studies to explore the relationship between increasing antimicrobial resistance and agricultural or human antibiotic use may be valuable.     

Pattern of antibiotic susceptibility in Campylobacter jejuni isolates of human and poultry origin

Campylobacter jejuni antibiotic resistance is rising with a variable geographical pattern; but there is limited data from the Arabian Gulf region. We assessed the sensitivity of human (117) and chicken (33) C. jejuni isolates to erythromycin, ciprofloxacin, tetracycline and trimethoprim-sulfamethoxazole by agar dilution, disc diffusion and the E test. Only 2 human isolates were resistant to erythromycin. In contrast, over 80% of chicken and human isolates were resistant to ciprofloxacin. A significantly higher proportion of chicken isolates than human isolates were resistant to tetracycline, with much higher MIC(50) values (P < 0.001). The MIC(90) for trimethoprim-sulfamethoxazole by agar dilution was 40 microg/ml. Comparison of the results of the agar dilution method and E test showed 1 major disagreement and 8 minor disagreements for erythromycin, 4 major disagreements for ciprofloxacin and 23 disagreements for tetracycline (19 were major disagreements). This was the first study to describe the pattern of antibiotic resistance in Campylobacter isolates in this region; the results indicate a high degree of erythromycin sensitivity that validates the continued use of this agent as a first-line therapy for Campylobacter enteritis. These findings have wide implications because of the large, highly mobile expatriate population in this setting. In addition, the correlation between agar dilution and disc diffusion supports the use of the latter as an alternative susceptibility testing method for Campylobacter.     

Characterization and antibiotic sensitivity of Campylobacter jejuni and Campylobacter coli isolated from children at the Lagos University Teaching Hospital (LUTH), Lagos, Nigeria

One hundred and thirteen rectal swabs and 87 faecal samples obtained from the Paediatric casualty of the Lagos University Teaching Hospital, Lagos, Nigeria were processed for Campylobacter jejuni/coli. Twenty-two (11%) of the specimens were positive for C. jejuni. Biotyping results showed that nine (41%) and eight (36%) belonged to C. jejuni biotypes I and II respectively, while three (14%) and two (9%) belonged to C. coli biotypes I and II. Serotyping results revealed that C. jejuni biotypes I and II and C. coli biotypes I and II belonged to different serotypes with serotypes A9 and A36 being the most prevalent. In-vitro antibiotic sensitivity testing using the disc method showed that 18 (82%) of the Campylobacter jejuni/coli isolates were sensitive to erythromycin and nalidixic acid, while 16 (73%) were sensitive to streptomycin. All were resistant to penicillin, while four (18%) and six (27%) were sensitive to tetracycline and cloxacillin respectively. We therefore recommend the use of erythromycin and streptomycin for cases of Campylobacter enteritis requiring antimicrobial therapy in Lagos, Nigeria.     

Biotypes, serogroups and antibiotic susceptibility of Campylobacter jejuni and Campylobacter coli in Chile

Phenotypic markers were studied in 105 strains of thermophilic campylobacters isolated from human beings, animals and drinking water in Santiago, Chile. The strains were identified as Campylobacter jejuni (n = 49) and Campylobacter coli (n = 56). Biotypes I and II (Lior schema) accounted for 96% C. jejuni isolates, the other 4% being biotype IV but the two biotypes of C. coli were about equally represented. A total of 28 serogroups (Lior's heat-labile antigens) were identified. Lior 13, 9, 79, 2 and 4 were prevalent among the C. jejuni, while Lior 8, 21 and 29/75 were prevalent among the C. coli isolates. These serogroups accounted for 73% all isolates. The distribution of biotypes and serogroups in patients and asymptomatic persons were similar. Human campylobacters were often resistant to ampicillin (31%) but sensitive to erythromycin and furazolidone. Swine C. coli isolates proved resistant to streptomycin (46%), tetracycline (38%) and erythromycin (15%). Determination of phenotypic and serological characters provides valuable epidemiological markers in the study of campylobacter infections.     

肉鸡源多重耐药空肠、结肠弯曲菌的耐药分子特征

目的了解肉鸡源空肠和结肠弯曲菌的耐药谱特征,检测多重耐药菌株Ⅰ类整合子/基因盒、gyrA基因突变位点、tetO基因、23S rRNA突变位点的分子特征。方法利用PCR检测弯曲菌Ⅰ类整合子/基因盒的存在情况;利用MAMA PCR技术检测弯曲菌gyrA基因第257位碱基的突变情况;针对弯曲菌23S rRNA的V区2075突变位点检测突变菌株。结果多重耐药菌株占分离株的94.5%。146株多重耐药空肠和结肠弯曲菌中Ⅰ类整合子检出率为98.6%,有78株菌株检出3种基因盒,1 000 bp+750 bp+500 bp+250 bp为主要谱型,所占比例为92.3%;有131株在gyrA喹诺酮类耐药决定区发生突变,突变率为92.9%。127株四环素耐药弯曲菌tetO基因的检出率为95.3%。81株红霉素耐药菌株中,23S rRNA的V区2075处突变发生率为96.3%。结论空肠和结肠弯曲菌分离株携带aadA2耐药基因盒,与氨基糖苷类药物的耐药性相关;gyrA基因突变、tetO基因的携带以及23S rRNA突变,与弯曲菌对喹诺酮、四环素和大环内酯类耐药密切相关。     

肉鸡源弯曲菌的分离、多重PCR鉴定及其耐药性分析

目的了解肉鸡屠宰加工过程中弯曲菌的污染及其耐药情况。方法根据GB4789．9-2008,采用增菌培养、选择性平板分离、生化鉴定从肉鸡屠宰过程中分离疑似弯曲菌,并以弯曲菌属的16s球NA、空肠弯曲菌的Hip0和结肠弯曲菌的CeuE为靶基因,采用三重PCR方法对疑似菌株进行鉴定。采用琼脂稀释法对弯曲菌阳性菌株进行8种常用抗生素的药敏试验,参考CLSI标准（2010）判定药敏结果。结果根据形态特征、生化指标及PCR鉴定结果,从651份样品中,鉴定出空肠弯曲菌160株、结肠弯曲菌130株,其他弯曲菌11株,弯曲菌总分离率为46．24％;其中屠宰前、屠宰过程中及屠宰后鸡肉中弯曲菌的污染率分别为56．10％、31．00％、17．00％,可能存在由屠宰前向屠宰后传播趋势。药敏试验表明,弯曲菌对环丙沙星、左氧氟沙星、四环素和林可霉素的耐药率较高,分别为93．02％、87．71％、87．71％、80．07％,对庆大霉素、红霉素、链霉素、氟苯尼考的耐药率分别为67．11％、49．50％、31．89％、13．29％。结论肉鸡屠宰过程中弯曲菌的污染及其耐药情况较为严重,应该加强卫生和抗生素使用监督。     

贵州省鸡源弯曲菌的流行现状及抗生素敏感谱研究

目的 了解贵州省鸡源弯曲菌的流行现状和耐药特征,为兽医和人医临床上抗生素的合理使用提供参考。方法 随机从贵州省东、西、南、北、中5个片区中的养殖场和农贸市场采集359份新鲜粪便样本进行分离培养、生化及MALDI-TOF MS鉴定。采用琼脂稀释法检测分离株对7类11种不同抗生素的耐药性,通过PCR方法检测耐药基因的携带情况。结果 弯曲菌总体检出率为43.5%,包括68株(43.6%)空肠弯曲菌和88株(56.4%)结肠弯曲菌;对其中84株弯曲菌进行药敏实验和耐药基因检测,结果显示分离株对11种抗菌药物产生了38种耐药谱,空肠弯曲菌和结肠弯曲菌的优势谱型都为NAL-CIP-TET;81.0%的弯曲菌呈多重耐药,其中结肠弯曲菌的多重耐药率(91.7%)高于空肠弯曲菌(54.2%);红霉素、阿奇霉素、泰利霉素、克林霉素、庆大霉素和链霉素耐药株的耐药表型与耐药基因携带相关;交叉耐药显示,红霉素与阿奇霉素呈高度相关(|r|=0.79>0.7),庆大霉素与链霉素呈中度相关(|r|=0.46>0.4),萘啶酸与环丙沙星(|r|=0.36<0.4)、氯霉素与氟苯尼考呈弱相关(|r|=0.04<0.4)。结论 贵州省鸡源弯曲菌存在区域性流行特征和耐药差异,多重耐药现象严重,存在通过食物链传播给人的风险。     

Serotypes and antimicrobial resistance of Campylobacter jejuni isolated from humans and animals in Thailand

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.     

鸭源弯曲菌的分离鉴定及其耐药性、毒力基因分析

目的了解鸭肉生产链中弯曲菌的污染情况及其耐药性和毒力基因分布情况。方法根据GB 4789.9-2014,从肉鸭屠宰链中分离疑似弯曲菌,采用三重PCR方法,对疑似菌株进行准确鉴定;采用微量肉汤稀释法,对弯曲菌分离菌株进行8种抗菌药物敏感性试验,参考NARMS标准判定药敏试验结果;利用PCR检测与弯曲菌致病相关的4个毒力基因。结果根据形态特征、生化指标及PCR鉴定结果,从489份样品中,鉴定出空肠弯曲菌100株、结肠弯曲菌79株,其他弯曲菌8株,弯曲菌的总体分离率为38.24%,肉鸭屠宰前、脱毛环节、掏膛环节、屠宰后样品弯曲菌分离率分别为76.33%、5.62%、24.00%、0%;药敏试验结果表明弯曲菌对TET(95.72%)、CLI(90.91%)的耐药率较高,对AZI(63.64%)耐药率居中,对CIP(31.02%)、GEN(34.76%)、NAL(37.43%)、ERY(41.18%)、CHL(41.18%)的耐药率相对较低,所分离菌株多重耐药现象较为普遍,多重耐药率达72.19%。弯曲菌分离株对黏附相关基因cadF、鞭毛基因flaA、侵袭蛋白基因iamA、毒素调节基因cdtB的携带率分别为100%、80.75%、71.12%、94.65%。结论肉鸭屠宰过程中存在不同程度的弯曲菌污染,且其耐药情况较为严重,毒力相关基因广泛存在于弯曲菌中,应该加强卫生管理和抗菌药物使用监督。     

猪源弯曲菌的分离鉴定及耐药性分析

目的 为调查猪肠道内空肠弯曲菌和结肠弯曲菌的流行和耐药性状况。方法 本试验自北京郊区养猪场和屠宰场采集猪肠道粪便样品,经增菌培养后利用三重PCR进行弯曲菌属、空肠弯曲菌和结肠弯曲菌的检测,进而对PCR检测阳性样品进行弯曲菌的分离鉴定,最后对分离鉴定的弯曲菌分离株进行药敏试验鉴定。结果 本试验共采集猪肠道和肛门棉拭子样品241份,PCR检测结肠弯曲菌阳性样品数为178份,阳性率为73.9%,而空肠弯曲菌阳性样品数5份,阳性率仅为2.1%。经分离鉴定后共获得结肠弯曲菌菌株63株,分离率为35.4%,未分离获得空肠弯曲菌菌株。对26种抗生素的药敏试验结果显示结肠弯曲菌分离株对氯霉素(100%)、丁胺卡那(93.65%)、强力霉素(91.48%)、庆大霉素(82.54%)和阿莫西林(82.54%)等抗生素比较敏感,而对头孢哌酮(100%)、 头孢氨苄(100%)、头孢拉啶(100%)、头孢唑啉(98.41%)、头孢克肟(92.06%)、萘啶酸(92.06%)、链霉素(90.48%)、环丙沙星(90.32%)、诺氟沙星(88.89%)和青霉素(87.30%)具有显著的耐药性;而且分离株多重耐药现象比较普遍,主要集中于14-20耐。结论 本试验结果显示猪肠道内普遍存在结肠弯曲菌,而且菌株对多种抗生素产生了显著的耐药性。     

突变敏感性分子开关检测肺炎支原体对大环内酯类抗生素的耐药性研究

目的 应用突变敏感性分子开关检测肺炎支原体对大环内酯类抗生素的耐药性。方法 采用微量稀释法检测5种常用大环内酯类抗生素对40株Mp临床分离株的药物敏感性;建立高保真聚合酶和3'硫化修饰引物的分子开关,用分子开关进行Mp临床分离株的PCR扩增,检测其是否存在Mp 23S rRNA 2063、2064和2617 3个热点突变,并通过基因测序进一步确定是否存在点突变,分析点突变与大环内酯类抗生素敏感性之间的关系。结果 5种大环内酯类抗生素中,Mp对14元环的红霉素和克拉霉素耐药程度最高,其MIC≥128 mg/L;对15元环的大环内酯类抗生素阿奇霉素和交沙霉素相对敏感,其中交沙霉素抗Mp活性最高,其MIC≤4 mg/L。用高保真聚合酶和3'硫化修饰引物的分子开关行PCR扩增,检测出35株发生了2063位点基因突变,3株发生2064位点基因突变,未检测出2617位点突变。用基因测序检测到35株Mp发生A2063G的突变,3株发生A2064G的突变,未检测到2617位点突变,与分子开关的检测结果一致,并且2063、2064位点突变Mp株均对大环内酯类药物高度耐药。结论 分子开关可识别23S rRNA基因突变,可用于分析Mp对大环内酯类抗生素的敏感性。     

鸡肉空肠弯曲杆菌的分离鉴定及耐药性分析

目的 分离和收集食源性空肠弯曲杆菌的优势流行株,了解市场上鸡肉中空肠弯曲杆菌的污染和药物敏感性情况。方法 根据GB/T4789.9-2003、SN0175-2010、ISO10272-1:2006、FDA/BAM:2001、USDA/FSIS:1998等方法优化组合出一套对动物性食品源空肠弯曲杆菌有效的分离鉴定方法,从市场上鸡肉中分离疑似空肠弯曲杆菌,并进一步用生化试验及PCR方法进行准确鉴定。采用微量肉汤稀释法测定了所分离的空肠弯曲杆菌对22种常见抗菌药物（组合）的最低抑菌浓度值（MIC）。结论 根据培养特征、形态特征、生化试验和PCR结果准确鉴定出21株空肠弯曲杆菌,其污染率为11.5%。86%生化试验阳性的菌株经PCR鉴定为阳性。将空肠弯曲杆菌标准菌株和随机选出的分离株的16S rDNA扩增序列进行比对,二者同源率为100%。药敏试验表明,14.3%的分离菌株对氨苄西林具有耐药性;大多数菌株对头孢类抗生素MIC值相对较高;42.9%的菌株对萘啶酸具有耐药性;所有分离株对环丙沙星、四环素、红霉素、氯霉素、庆大霉素、链霉素不耐药。     

鸡肉生产链空肠弯曲杆菌的耐药性研究

目的 了解鸡肉生产链(养殖场-屠宰场-市场)中空肠弯曲杆菌分离株的耐药情况。方法 针对成都市及雅安市养鸡场、屠宰场和市场中分离的180株空肠弯曲杆菌,采用微量肉汤稀释法,检测鸡肉生产链中空肠弯曲杆菌对8种抗菌药物的耐药情况;采用错配扩增突变分析PCR(MAMA PCR)技术,检测137株耐环丙沙星的空肠弯曲杆菌的gyrA基因第257位突变情况,对gyrA基因突变进行分析。结果 药敏试验表明,空肠弯曲杆菌分离株对环丙沙星、左氟沙星、四环素和克林霉素的耐药率较高,分别为94.44%、93.89%、91.67%和78.33%;对红霉素(20.00%)、链霉素(20.56%)、庆大霉素(17.78%)、氟苯尼考(12.22%)呈现不同的耐药率。从养殖场到市场,鸡肉生产链中空肠弯曲杆菌对上述8种抗菌药物的耐药率呈持平或上升趋势。MAMA PCR 结果表明,95.62%(131/137)的环丙沙星耐药空肠弯曲杆菌在gyrA基因第257位发生点突变,10株环丙沙星敏感菌株均没有检测出gyrA基因的突变;gyrA基因耐药决定区的测序结果表明,环丙沙星耐药菌株MJF31和MJF53都在第257位碱基发生了ACA→ATA(苏氨酸到异亮氨酸)的突变,而对环丙沙星敏感的菌株JF9和JF136均未发生该类突变。结论 鸡肉生产链中空肠弯曲杆菌耐药性比较普遍,对喹诺酮类药物耐药率较高,多重耐药菌株较突出,应加强对养殖场和食品源空肠弯曲杆菌耐药性的监测。     

深圳市408份不同来源样本弯曲菌的检测及耐药特征分析

目的 分析深圳市不同来源样本弯曲菌的流行和抗生素敏感特征,与往年菌株的耐药特征进行比对,获得深圳地区弯曲菌的流行现状及耐药变化。方法 采用增强过滤法分离弯曲菌并应用琼脂稀释法进行抗生素敏感性分析。结果 408份不同来源样本中,鸡盲肠的弯曲菌阳性率最高,达72.0%(36/50),鸡肉的分离率次之,为49.3%(34/69)。腹泻病人弯曲菌分离率为10.7%(17/159)。牛肉、猪肉中弯曲菌分离率低,海鲜中分离到1株空肠弯曲菌,生菜未分离到弯曲菌。53株腹泻病人来源和鸡源空肠弯曲菌耐药率最高的是萘啶酸(94.3%)和环丙沙星(94.3%),其次是四环素(92.4%)、氟苯尼考(75.5%)。32株腹泻病人来源和鸡源结肠弯曲菌耐药率最高为萘啶酸、环丙沙星、四环素(100%)。73.6%(39/53)的空肠弯曲菌和100%(32/32)的结肠弯曲菌存在多重耐药性。与往年相比,鸡源空肠弯曲菌对大环内酯类抗生素的耐药增强,腹泻病人来源空肠弯曲菌对萘啶酸-环丙沙星-四环素-氟苯尼考多重耐药性增强。结论本地区首次在腹泻患者中分离到简明弯曲菌,其病原特征有待于进一步分析。深圳地区腹泻病人来源及鸡源空肠弯曲菌有耐药增强现象,应引起重视。     

An observational clinic-based study of diarrheal illness in deployed United States military personnel in Thailand: presentation and outcome of Campylobacter infection

Campylobacter is a leading cause of traveler's diarrhea in Thailand. Since resistance to quinolones is high among Campylobacter isolates, empiric therapy with quinolones for traveler's diarrhea may be ineffective in this region. We conducted an observational study among 169 U.S. military personnel with acute diarrhea and compared their microbiologic findings to those of 77 asymptomatic personnel deployed to Thailand in May 1998. Of 146 pathogenic bacterial isolates, the most common were nontyphoidal Salmonella (n = 31), enterotoxigenic Escherichia coli (n = 24), and C. jejuni/coli (n = 23). Campylobacter was strongly associated with disease (odds ratio = 5.9; 95% confidence interval = 1.3-37.3), with a more severe clinical presentation, and with a reduced functional ability at presentation (P = 0.02). In vitro resistance to ciprofloxacin was observed in 96% of the Campylobacter isolates. Sub-optimal treatment response to ciprofloxacin was observed in 17% of the cases of Campylobacter infection versus 6% due to other causes. These results highlight the importance of Campylobacter as a cause of severe traveler's diarrhea in Thailand and illustrates the ongoing problem with antibiotic-resistant strains and associated treatment problems.     

Bacterial enteric pathogens in children with acute dysentery in Thailand: increasing importance of quinolone-resistant Campylobacter

Current data on pathogen prevalence and drug resistance patterns are important for treatment and vaccine-development strategies. An etiologic study of acute bacterial dysentery was conducted in children up to 12 years of age in 2 major hospitals in and around Bangkok. Stool samples or rectal swabs and clinical data were collected. Standard microbiological methods were used to detect Salmonella, Shigella, Campylobacter, Vibrio, Aeromonas and Plesiomonas. Pathogenic E. coli (ETEC, EIEC, STEC) was identified by digoxigenin-labeled probes. A total of 623 cases were enrolled: median age 11.0 months (range 1 month-12 years). At least one bacterial pathogen was isolated in 55% of cases. Campylobacter was the most common pathogen found (28%), whereas Salmonella, Shigella and ETEC were isolated from 18%, 9% and 6% respectively. EIEC, Vibrio and Plesiomonas were isolated from <1% and no STEC was detected. C. jejuni serotypes 36, 4 and 11 were the most common. The mean age of cases with Campylobacter was significantly lower than with Shigella (17.9 vs 52.8 months, p<0.001). Clinical presentations of Campylobacter and Shigella infections were compared: fever (28% vs 37%), abdominal colic (62% vs 80%, p<0.05), vomiting (38% vs 70%, p<0.001) and bloody stools (52% vs 48%). The Campylobacter isolates (80% C. jejuni, 20% C. coli) were 90% resistant to ciprofloxacin but sensitive to macrolides. All the Shigella isolates (70% S. sonnei) were sensitive to quinolones. Our study illustrates the increasing importance of quinolone-resistant Campylobacter and the decline of Shigella in the etiology of dysentery in Thailand. The clinical presentation of campylobacteriosis is similar to that of shigellosis, except that the patients may be younger and there may be less association with colic and vomiting; having fecal leukocytes will be >10/HPF. The use of macrolide antibiotics rather than quinolones would be reasonable in children <24 months of age; fluoroquinolones will be ineffective in at least half of culture-positive cases.     

扬州市区腹泻人群空肠弯曲菌和结肠弯曲菌流行状况及耐药性分析

目的了解扬州市区腹泻人群中空肠弯曲菌和结肠弯曲菌的感染流行和耐药性状况。方法采用多重PCR方法对扬州市区两所医院门诊部和住院部的腹泻人群进行空肠弯曲菌和结肠弯曲菌感染状况调查,采用琼脂扩散法测定分离株的耐药性。结果在2937份粪便样品中,142份空肠弯曲菌阳性、平均阳性率4.83%,10份结肠弯曲菌阳性、平均阳性率0.34%。不同医院间感染率差异不显著(P>0.05),门诊部感染率极显著高于住院部(P<0.01),7岁以下幼儿感染率极显著高于其它人群(P<0.01),6月-8月感染率显著高于其它月份(P<0.05)。93株空肠弯曲菌分离株对21种抗生素高度敏感的是:庆大霉素91.40%、阿齐红霉素89.25%、红霉素88.46%、阿莫西林87.10%、链霉素83.87%、头孢噻肟81.72%、卡那霉素81.72%,高度耐药的是:头孢哌酮100%、复方新诺明100%、头孢拉定97.85%、头孢克罗93.55%、环丙沙星91.40%、萘啶酸91.40%、左旋氧氟沙星88.17%、土霉素87.50%。耐药菌株耐药谱主要集中在9耐至14耐,达81.71%,两医院分离株多重耐药性无显著性差异(P>0.05),不同诊区分离菌多重耐药性存在显著性差异(P<0.05)。结论扬州市区腹泻人群空肠弯曲菌和结肠弯曲菌的流行及耐药状况呈现多样化和复杂化,研究结果为正确评价腹泻人群弯曲菌的流行状况和制定切实可行的防控措施提供了科学依据。     

Class 1 integrons and multidrug resistance among Escherichia coli isolates from human stools

Three hundred and eighteen Escherichia coli isolates from stools of healthy volunteers and outpatients from a major university hospital in southern Thailand were tested for the presence of class 1 integrons using multiplex-PCR and for their susceptibility against 12 antimicrobial agents using standard disc diffusion method. Based on the presence of intl1, 162 isolates harbored class 1 integrons, which were more prevalent in isolates from outpatients compared with those from healthy volunteers. The majority (85%) of the isolates were resistant to at least one antimicrobial agent with the following percent resistance: streptomycin 66%, tetracycline 60%, sulphamethoxazole 59%, ampicillin 52%, trimethoprim/sulphamethoxazole 47%, kanamycin 30%, nalidixic acid 27%, ciprofloxacin 23%, norfloxacin 22%, amoxicillin/ clavulanic acid 16%, gentamicin 8%, and amikacin 2%. The most frequent pattern of multiresistant strains (11%) was sulphamethoxazole- trimethoprim/sulphamethoxazole -ampicillin-tetracycline-streptomycin. Multiple drug resistance was more frequent in integron-positive isolates (89%) than those in integron-negative E. coli (57%). These data indicate that human fecal E. coli is a reservoir of antibiotic-resistant genes that poses a significant risk of the spread of microbial resistance in the community.     

江苏奶牛空肠弯曲菌和结肠弯曲菌流行状况及耐药性分析

目的了解江苏省奶牛空肠、结肠弯曲菌流行及耐药状况。方法采用多重PCR方法对10个奶牛场的产奶牛、育成牛和饲养环境进行空肠弯曲菌和结肠弯曲菌流行状况调查,采用琼脂扩散法测定分离株的耐药性。结果1531份样品中,119份空肠弯曲菌阳性,平均阳性率7.77%;3份结肠弯曲菌阳性,平均阳性率0.20%;空肠弯曲菌、结肠弯曲菌阳性率最高分别为30.91%、3.57%。在三类样品中,产奶牛空肠弯曲菌、结肠弯曲菌阳性率分别为5.02%、0.32%,育成牛空肠弯曲菌阳性率为8.70%、未检出结肠弯曲菌,环境样品空肠弯曲菌、结肠弯曲菌阳性率为10.28%、0.18%。35株奶牛空肠弯曲菌分离株对8大类21种抗生素高度敏感率的是:阿莫西林100%、阿齐红霉100%、链霉素97.14%、庆大霉素94.29%、红霉素91.43%、头孢噻肟82.86%、克林霉素82.86%;高度耐药率的是:头孢哌酮100%、恩诺沙星100%、环丙沙星97.14%、复方新诺明97.14%、左旋氧氟沙星94.29%、萘啶酸94.29%、头孢拉定94.29%、诺氟沙星91.43%、头孢克罗88.57%。菌株耐药谱显示,35株分离株的耐药主要集中在9耐到12耐,占88.57%,产奶牛分离株的多重耐药性较其它分离株更严重。结论我国奶牛群中空肠弯曲菌、结肠弯曲菌的流行和耐药状况呈现多样化和复杂化,研究结果为正确评价我国奶牛群弯曲菌的流行状况和制定切实可行的防控措施提供科学依据。     

Antimicrobial susceptibility of Campylobacter jejuni and Campylobacter coli isolated from human diarrheic samples

One hundred forty-seven Campylobacter were isolated using 3,204 samples taken from sporadic diarrheic patients from January 2001 to December 2003. The detection rate of Campylobacter in 16 to 30 year old patients (12.9%, 83/641) was significantly higher than that in patients less than 16 years of age, 5%, (29/1,155) (p < 0.001) and more than 30 years of age, 2.5% (35/1,408) (p < 0.001), respectively. The highest detection rate was obtained from the stool of males in the 16 to 30 year old range during the months from May to August, 26% (32/123). If the minimal inhibitory concentration (MIC) breakpoint for resistance of gentamicin (GM), erythromycin (EM), ciprofloxacin (CPFX), tetracycline (TC) were defined tentatively > or = 16 microg/ml, > or = 16 microg/ml, > or = 2 microg/ml, > or = 16 microg/ml, the resistant rate would be 0.0%, 0.0%, 22.0%, 42.8% in C. jejuni, 0.0%, 62.5%, 62.5%, 87.5% in C. coli, respectively. All the Campylobacter isolates were susceptible to GM. Three of the 8 C. coli isolates were multi-resistant in EM, CPFX, and TC. Five highly EM resistant strains with an MIC of > or = 512 microg/ml did not show any zone around the EM disk; 7 susceptible strains with an MIC of less than 16 microg/ml showed = zones of 24mm to 36mm and revealed a good correlation with the Etest method and the agar dilution method. Between the two time periods of January 2001-June 2002 and July 2002-December 2003, the resistant rate of CPFX in C. jejuni decreased from 27.5% to 15.5%, however, that was not significant decrease (p = 0.133).