肺炎链球菌对红霉素的耐药表型及耐药基因

目的　研究肺炎链球菌对红霉素的耐药表型及耐药基因。方法　根据美国临床实验室标准化委员会标准使用微量肉汤稀释法 ,检测 192株肺炎链球菌对红霉素、克林霉素、青霉素、喹诺酮类抗菌药物的最低抑菌浓度 (MIC)。应用红霉素、克林霉素、螺旋霉素纸片行三纸片扩散法 ,检测 14 8株红霉素耐药肺炎链球菌的耐药表型。应用PCR检测 14 8株红霉素耐药肺炎链球菌携带的耐药基因。结果　肺炎链球菌对青霉素的耐药率 (中介率 耐药率 )为 4 2 7% ,对红霉素、克林霉素的耐药率分别为 77 6 %、6 6 7%。 14 8株红霉素耐药株中 ,耐药基因以ermB基因 (79 1% )为主 ,耐药表型以内在型耐药 (cMLS) (85 1% )为主。携带ermB基因的肺炎链球菌 ,74 4 %的菌株对红霉素的MIC值 >16 0 μg/ml;而携带mefA基因的肺炎链球菌对红霉素的MIC值在 0 5～ 4 0 μg/ml之间。 结论肺炎链球菌对红霉素的耐药率较高 ;耐药表型以cMLS为主 ,耐药基因以ermB介导的靶位改变多见。     

上海地区儿童化脓性链球菌的红霉素耐药基因研究

目的 了解上海地区化脓性链球菌对红霉素的耐药情况及耐药基因谱的特点.方法 2004年11月至2006年6月经复旦大学附属儿科医院传染病门诊诊断为猩红热的患儿,其咽拭子培养分离获得100株化脓性链球菌.应用PCR及序列分析法检测红霉素耐药基因mefA、ermA、ermB在该批菌株中的分布规律及其与红霉素耐药性的关系.结果上海地区化脓性链球菌的红霉素耐药率为98%,克林霉素耐药率为95%,两者耐药性的一致率为97%.100株菌株中含ermB基因的化脓性链球菌94株,占所有菌株的94%,对红霉索耐药率为100%;含mefA基因的化脓性链球菌16株,占所有菌株的16%,对红霉素耐药率为100%;100株菌株中未发现ermA基因.5株菌株未发现ermB基因及mefA基因,其中2株对红霉素敏感,3株对红霉素耐药.mefA基因单独阳性的菌株仅占1%.结论上海地区化脓性链球菌对红霉奈普遍具有较高耐药率,且与克林霉素存在较严重的交叉耐药.ermB基因是决定上海地区化脓性链球菌对红霉素耐药的重要基因.     

十堰地区婴幼儿社区获得性肺炎常见病原体致病情况及耐药性变迁分析

目的分析十堰地区婴幼儿社区获得性肺炎(CAP)常见病原体致病情况及耐药性的变迁。 方法选取2018年2月至2019年2月十堰区多家医院收治的1 282例CAP患儿,采集所有患儿深部痰液标本,对痰液中细菌菌种进行鉴定,采用MIC法进行药敏试验,并分析检出细菌对常用抗菌药物的耐药情况。 结果282例CAP患儿中病原体检出阳性者684例(53.35%),其中肺炎链球菌检出146例(21.35%),肺炎链球菌、大肠埃希菌、金黄色葡萄球菌、铜绿假单胞菌、产气肠杆菌、阴沟肠杆菌在年龄≤12个月的患儿中检出率明显高于年龄12～36个月的患儿(均P<0.05)。1 282例患儿肺炎支原体检出率为6.16%(79/1282),肺炎衣原体检出率为11.39%(146/1 282),肺炎支原体/衣原体在年龄12～36个月的患儿中检出率分别为13.71%(51/372)、25.81%(96/372)明显高于年龄≤12个月患儿的3.08%(28/910)、5.49%(50/910)(P<0.05)。在革兰氏阳性菌中,肺炎链球菌对红霉素、四环素、克林霉素耐药率均>80%,金黄色葡萄球菌对青霉素、红霉素、克林霉素、氨苄西林耐药率均>50%;肺炎链球菌和金黄色葡萄球菌对万古霉素、利奈唑胺均敏感。在革兰氏阴性菌中,大肠埃希菌和肺炎克雷伯菌均对头孢唑林、头孢他啶、头孢吡肟、头孢曲松、氨苄西林、氨曲南耐药率>70%;流感嗜血杆菌对氨苄西林耐药率最高;铜绿假单胞菌对头孢曲松、头孢替坦均100%耐药;革兰氏阳性菌对哌拉西林及阿米卡星耐药率最低。 结论十堰地区婴幼儿社区获得性肺炎常见病原体为肺炎链球菌,主要对红霉素、四环素、克林霉素耐药率均较高,临床应当使用敏感抗菌素提高治疗效率。     

肺部感染病原菌检测与抗菌药物耐药状况分析

目的探讨引起肺部感染的病原菌及其耐药状况。方法对187例肺部感染患者痰液标本进行病原菌鉴定及药敏试验检测,分析结果。结果 187份标本共检出病原菌164株,培养阳性率为87.70%,其中革兰氏阴性菌占71.95%,革兰氏阳性菌占18.29%,真菌占9.76%,革兰阴性菌中以铜绿假单胞菌、肺炎克雷伯菌、大肠埃希氏菌、肠杆菌属、鲍曼不动杆菌为主,革兰氏阳性菌中以金黄色葡萄球菌、肺炎链球菌、溶血性葡萄球菌为主,真菌主要为白色假丝酵母菌,占7.93%;检出的革兰氏阴性菌对亚胺培南、美罗培南、阿米卡星耐药率低,铜绿假单胞菌对氨苄西林、氨苄西林/舒巴坦完全耐药,肺炎克雷伯菌对氨苄西林完全耐药,肠杆菌属对头孢呋辛酯完全耐药,鲍曼不动杆菌对氨曲南、头孢呋辛酯完全耐药;检出的革兰氏阳性菌对万古霉素、夫西地酸、莫西沙星耐药率低,金黄色葡萄球菌对红霉素、克林霉素完全耐药,肺炎链球菌对红霉素完全耐药,溶血性葡萄球菌对青霉素、氨苄西林、氨苄西林/舒巴坦、亚胺培南、红霉素、克林霉素、环丙沙星、庆大霉素、磷霉素均完全耐药。结论引起肺部感染患者的病原菌主要以铜绿假单胞菌、肺炎克雷伯菌、大肠埃希氏菌、肠杆菌属、鲍曼不动杆菌为主的革兰氏阴性菌为主,检出病原菌均对临床常用抗菌药物存在一定耐药性。     

2006～2007年南京地区肺炎链球菌耐药情况分析

目的 了解南京地区肺炎链球菌对常用抗菌药物的耐药性.方法 琼脂稀释法测定130株肺炎链球菌对14种抗菌药物最低抑菌浓度.结果 130株肺炎链球菌中,耐青霉素肺炎链球菌的检出率为51.5%;头孢呋辛、头孢噻肟、阿莫西林、头孢曲松的耐药率依次为69.2%、17.7%、6.2%和3.1%;四环素、红霉素、阿奇霉素和克林霉素耐药率分别为93.8%、92.3%、90.8%和89.2%;万古霉素、新喹诺酮类左氧氟沙星和莫西沙星、替加环素、利奈唑胺均敏感.结论 南京地区肺炎链球菌对青霉素、红霉素、阿奇霉素、克林霉素、四环素、头孢呋辛等抗生素耐药性高,应注意合理选择用药.     

204例社区获得性肺炎患者感染草绿色链球菌种类及其耐药性分析

目的分析社区获得性肺炎患者感染草绿色链球菌种类及其耐药性。方法 2016年9月至2017年9月本院收治的社区获得性肺炎患者204例,收集相关临床资料;采集患者痰液标本,培养法分离草绿色链球菌,并进行药敏试验。取分离的不同种草绿色链球菌分别与肺炎双球菌混合培养,观察后者的生长情况。结果共分离出300株草绿色链球菌,以咽峡炎链球菌和星座链球菌居多,分别占42.7%和28.3%,缓症链球菌和唾液链球菌分别占14.3%和14.7%。纸片法测定分离株草绿色链球菌对7种抗菌药物有不同程度的耐药性,其中对红霉素、克林霉素及四环素的耐药率分别为71.7%、62.3%和61.3%;对氯霉素、青霉素G、阿莫西林的耐药率较低,分别为4.7%、2.7%和2.3%;对美罗培南、万古霉素、头孢噻肟、头孢吡肟和利奈唑胺均不耐药。左氧氟沙星耐药率咽峡炎链球菌和缓症链球菌分别为15.6%和27.3%,星座链球菌和唾液链球菌分别为4.7%和6.8%。肺炎链球菌与草绿色链球菌混合培养后数量显著减少(P0.05)。结论社区获得性肺炎患者感染的草绿色链球菌有4种,对红霉素、克林霉素和四环素的耐药率均较高,而对左氧氟沙星的耐药率差异较大,须根据药物敏感试验结果指导临床合理用药。     

肺炎链球菌大环内酯药物耐药性及耐药基因erm、mef的检测

肺炎链球菌是引起呼吸道感染的常见菌.近年来,耐药型肺炎链球菌出现迅猛,在我国和众多亚洲国家尤为明显~([1]).肺炎链球菌对大环内酯类抗生素的耐药率迅速增加,目前已成为一个全球性问题.其中对红霉素的耐药性已成为一个严重的现象~([2]).因此,我们对52株肺炎链球菌进行了大环内酯药物(红霉素和阿奇霉素)的耐药性情况和耐药基因erm(B)、erm(TR)、mef(A)及mef,(E)的检测分析.     

呼吸道感染肺炎链球菌分离株的耐药性分析

目的研究呼吸道感染患者肺炎链球菌分离株的耐药情况。方法通过细菌培养获得肺炎链球菌，对获得的肺炎链球菌进行药敏实验。结果呼吸道分离肺炎链球菌中青霉素耐药(PRSP)占39．3％，对头孢哌酮／舒巴坦、头孢克洛、头孢呋辛、头孢噻肟、头孢曲松、环丙沙星、左氧氟沙星、红霉素、克林霉素、复方新诺明、万古霉素、利福霉素的耐药率分别为39．3％，13．8％，36．6％，17．2％，35．9％，16．6％，40．0％，36．6％．51．7％，38．6％，60．0％，0和17．2％。结论吉林省肺炎链球菌对青霉素的耐药率已经处于较高水平，耐青霉素菌株对其他抗生素普遍耐药．已经发现对三代头孢菌素耐药菌株，未发现万古霉素耐药菌株。     

耐红霉素肺炎链球菌的分子生物学研究

目的研究耐红霉素肺炎链球菌的分子生物学特点。方法社区获得性肺炎呼吸道标本分离的肺炎链球菌共45株,进行抗生素药物敏感性试验,对耐药菌株采用PCR方法检测红霉素的耐药基因ermA/ermB/mefA,同时采用脉冲场凝胶电泳技术和青霉素结合蛋白基因多态性追踪耐药菌株之间的同源性,以获得耐药菌株的分子流行病学特点。结果45株肺炎链球菌中对红霉素耐药24株,均为多耐药肺炎链球菌;青霉素耐药14株,其中11株（78.6%）同时耐红霉素。22株（92%）的红霉素耐药株为MLS表型,即同时耐克林霉素,2株为M型耐药。经PCR扩增,20株（83.3%）具有ermA/B基因,6株（25.0%）同时有erm和mef基因,2株（8.3%）只有mef基因,2株未能检测到erm或mef基因。脉冲场凝胶电泳和青霉素结合蛋白基因多态性检测未发现不同地区相同的耐药克隆株。结论erm基因编码的核糖体突变是肺炎链球菌耐红霉素的主要机制,本研究未发现不同地区相同的耐药克隆株。     

48例儿童链球菌肺炎发生耐药性的危险因素分析

目的探讨链球菌肺炎(SP)儿童患者发生耐药菌感染的危险因素以及常见药物耐药情况。方法选取我院儿科病房48例儿童链球菌肺炎患者,对临床分离的48株肺炎链球菌进行药敏试验,针对常见抗菌药物耐药情况以及发生耐药性的危险因素进行分析。结果肺炎链球菌对红霉素、阿奇霉素的耐药率分别为93.75%和91.67%,对氨苄西林、头孢呋辛、头孢曲松敏感率分別为77.1%、83.33%、87.5%。单因素分析显示,年龄、使用疫苗以及就诊前应用抗生素等因素存在统计学差异(P﹤0.05),是儿童链球菌肺炎发生耐药菌感染的危险因素。并表现出多重耐药,尤其对青霉素和红霉素耐药的菌株。结论本医院所在儿科病房患儿链球菌肺炎耐药形势严峻,对多种抗生素呈广泛的不同程度的耐药,引起耐药的危险因素较多,应动态监测肺炎链球菌的耐药情况,合理选择抗生素,提高疗效。     

Prevalence and mechanisms of macrolide resistance in Streptococcus pyogenes in Ankara, Turkey

From 2002 to 2003, a total of 381 consecutive S. pyogenes isolates were obtained from throat swabs (n = 337) and samples of pus (n = 31), sputum (n=10) and blood (n = 3) at Hacettepe University Hospital. The susceptibility of the isolates to erythromycin was tested by the agar dilution method. Erythromycin resistant strains were then tested for their MICs to azithromycin, clindamycin, and penicillin, their phenotype of resistance to macrolides-lincosamides-streptogramin B (MLSB) and for the presence of macrolide resistance genes. The rate of resistance to erythromycin was 6.8%. Constitutive (cMLSB), inducible (iMLSB), and M phenotypes of resistance were detected in 7.7, 30.8, and 57.7% of resistant strains, respectively. One strain had both cMLSB and iMLSB phenotypes. All M phenotypes carried the mefA gene, all iMLSB phenotype carried the ermTR gene, 1 isolate with cMLSB phenotype harboured the ermB gene, and 1 isolate with cMLSB phenotype carried both the ermB and mefA genes. One strain which showed cMLSB and iMLSB phenotypes harboured the ermB gene.     

Characterization of macrolide resistance in Gram-positive cocci from Colombian hospitals: a countrywide surveillance.

OBJECTIVE: The characterization of macrolide resistance in Gram-positive cocci recovered from Colombian hospitals. METHODS: The resistance profiles and mechanism of macrolide resistance were investigated in isolates of Streptococcus pneumoniae (1679), Staphylococcus aureus (348), coagulase-negative staphylococci (CoNS) (175), and Enterococcus spp (123). Minimum inhibitory concentrations (MICs) for erythromycin (ERY) and clindamycin (CLI), detection of macrolide resistance genes, phenotypic characterization, and pulsed field gel electrophoresis (PFGE) of macrolide-resistant pneumococci were performed. RESULTS: Resistance to ERY and CLI was 3.3% and 2.3% for S. pneumoniae, 58% and 57% for S. aureus (94% for both compounds in methicillin-resistant Staphylococcus aureus (MRSA)), and 78.6% and 60.7% in methicillin-resistant Staphylococcus epidermidis, respectively. ERY resistance was 62% in Enterococcus faecalis and 82% in Enterococcus faecium. The MLS(B)-type accounted for 71% of S. pneumoniae and 100% of MRSA. The erm(A) gene was prevalent in MRSA, erm(B) in S. pneumoniae and enterococci, and erm(C) in CoNS isolates. Efflux pump genes (mef(A) genes) were mostly identified in S. pneumoniae (24%). The most common genotype amongst ERY-resistant pneumococci was the Spain(6B)-2 clone. CONCLUSIONS: The prevalence of macrolide resistance is low in Colombian pneumococci and high in MRSA (cMLS(B)-type).     

Phenotypic detection of constitutive and inducible clindamycin resistance in clinical isolates of Staphylococcus aureus and coagulase negative Staphylococcus on routine susceptibility plate

Increasing frequency of methicillin resistant Staphylococcus aureus infections and changing patterns in antimicrobial resistance have led to renewed interest in the use of macrolidelincosamide-streptogramin antibiotics. However therapy may fail either due to constitutive or inducible resistance. This study was undertaken to detect different phenotypes including inducible clindamycin resistance in clinical isolates of Staphylococcus aureus and coagulase negative Staphylococcus. Four hundred sixty five Staphylococcus aureus and 84 coagulase negative Staphylococci isolated from different clinical specimens were included in the study. On routine susceptibility testing plate clindamycin (2 microg) disk was placed at a distance of 15mm towards the centre from a peripherally placed erythromycin (15 microg) disk. Fisher exact test was used for statistical analysis. Out of 465 Staphylococcus aureus isolates, 237 (50.96%) were methicillin sensitive (MSSA) and 228 (49.03%) methicillin resistant (MLS(B)c).Over all 118 (25.37%) isolates showed constitutive resistance (MLS(B)c), 70 (15.05%) inducible clindamycin resistance, 143 (30.75%) MS(B) phenotype and 134 (28.81%) were susceptible to both erythromycin as well as clindamycin. Constitutive and inducible resistance to clindamycin were significantly higher in MRSA than MSSA (P=0.0000 and 0.0001 respectively). Out of 84 isolates of coagulase negative Staphylococci, 43 (51.19%) were methicillin sensitive (MSCNS) and 41(48.80%) methicillin resistant (MRCNS). Constitutive MLS(B) resistance was detected in 32 (38.09%), inducible clindamycin resistance 10 (11.90%), MS(B) phenotype 27 (32.14%) and 15 (17.85%) were susceptible to both erythromycin and clindamycin. Performing D test on a routine susceptibility plate saves material, manpower and time as inducible resistance can be reported simultaneously along with other susceptibility results.     

Antimicrobial susceptibility among community-acquired respiratory tract pathogens in the USA: data from PROTEKT US 2000-01

OBJECTIVES: The PROTEKT US surveillance program (Prospective Resistant Organism Tracking and Epidemiology for the Ketolide Telithromycin in the United States) commenced in 2000 to document the emergence and spread of antimicrobial resistance among respiratory tract pathogens in the United States. METHODS: During 2000-2001, 206 centers from 154 cities/metropolitan areas collected 16,727 clinical isolates (Streptococcus pneumoniae, n=10103, Streptococcus pyogenes, n=3918, Haemophilus influenzae, n=2706). RESULTS: Among S. pneumoniae isolates, 38.9% showed decreased susceptibility to penicillin (12.5% intermediate, 26.4% resistant) with marked geographical variability. The erythromycin resistance rate was 31.0% and highly correlated with penicillin resistance. The rate of fluoroquinolone resistance was 0.8%. Telithromycin was nearly uniformly active against S. pneumoniae (MIC(90) 0.5 mg/l). All isolates of S. pyogenes were penicillin-susceptible, 5.5% were resistant to erythromycin. Telithromycin minimum inhibitory concentrations (MICs) were lower than clindamycin and macrolide MICs against S. pyogenes (MIC(90) 0.03 mg/l versus 0.25 mg/l and 0.12 mg/l, respectively). 28.3% of H. influenzae isolates produced beta-lactamase. Telithromycin activity versus H. influenzae was not affected by beta-lactamase production. CONCLUSIONS: The PROTEKT US study confirms the widespread prevalence of antimicrobial resistance among common bacterial respiratory pathogens in the US, and re-affirms the importance of continued surveillance to guide optimum empiric therapy for patients with Community-acquired respiratory tract infections (CARTIs). The new ketolide, telithromycin, maintained potent activity against study isolates in vitro and offers promise for the effective treatment of CARTIs.     

Antibiotic susceptibility, serotype distribution and vaccine coverage of nasopharyngeal and oropharyngeal Streptococcus pneumoniae in a day-care centre in St. Petersburg, Russia

The objectives were to study serotypes and antibiotic susceptibility of Streptococcus pneumoniae carried by healthy children attending a day-care centre in St. Petersburg. S. pneumoniae colonization was investigated in 125 children aged 16-70 months. Antibiotic susceptibility was determined by E-test and disk diffusion. 83 S. pneumoniae cases were isolated in 75/125 (60%) children: 36/75 (48%) in the nasopharynx, 12/75 (16%) in the oropharynx and 27/75 (36%) in both. Carriage rates were 100%, 68%, 72%, 46% and 54% in children aged 12-23, 24-35, 36-47, 48-59 and >or=60 months, respectively. 97.6% of isolates were susceptible to penicillin. 61.4%, 32.5%, 19.3%, 16.7% and 6% isolates were non-susceptible to trimethoprim/sulfamethoxazole, tetracycline, clindamycin, erythromycin and chloramphenicol, respectively. 20.5% of isolates were multidrug resistant (MDR). 45% of isolates were of serotypes included in the 7-valent pneumococcal conjugate vaccine (7V-PCV); 64.9%, 56.8%, 32.4% and 27% of 7V-PCV serotypes were resistant to trimethoprim/sulfamethoxazole, tetracycline, clindamycin and erythromycin, respectively. The respective figures for MDR isolates were 100%, 94.1%, 70.6% and 76.5%; 76.5% of all MDR isolates were covered by 7V-PCV. In conclusion: 1) resistance to trimethoprim/sulfamethoxazole and tetracycline was high; 2) resistance to macrolides was higher than in other Russian regions; 3) 7V-PCV coverage was modest, but the vaccine may potentially reduce MDR-S. pneumoniae.     

Antimicrobial susceptibility of Streptococcus pneumoniae in the oropharynx of healthy preschool children and identification of risk factors

To determine the prevalence and antimicrobial susceptibility of Streptococcus pneumoniae in the oropharynx of healthy children, throat swabs were obtained from 683 children and cultured. The disk diffusion method and the E test were used to test the antimicrobial susceptibility of the isolated organisms. Twenty-nine children (4.2%) harbored S. pneumoniae in their oropharynx. Fifteen (51.7%) of the isolates showed intermediate resistance to penicillin and 14 (48.3%) were susceptible. All strains were susceptible to rifampicin and moxifloxacin. One was resistant to telithromycin. The rates of resistance to clindamycin, erythromycin, chloramphenicol and tetracycline were 41.3, 44.8, 34.4, and 44.8%, respectively. Risk factors for S. pneumoniae carriage were also assessed.     

Antibacterial resistance among children with community-acquired respiratory tract infections (PROTEKT 1999-2000)

OBJECTIVE: To determine the susceptibility of bacterial respiratory tract pathogens, isolated from children (0-12 years) as part of the global PROTEKT surveillance study (1999-2000), to a range of antibacterials, including the ketolide telithromycin. METHODS: Minimum inhibitory concentrations of the antibacterials studied were determined at a central laboratory using the NCCLS microdilution broth method. Macrolide resistance mechanisms were detected by PCR. RESULTS: Of 779 Streptococcus pneumoniae isolates worldwide, 43% were non-susceptible to penicillin (18% intermediate; 25% resistant) and 37% were resistant to erythromycin, with considerable intercountry variation. Eighteen per cent of 653 Haemophilus influenzae and >90% of 316 Moraxella catarrhalis isolates produced beta-lactamase. Of 640 Streptococcus pyogenes isolates, 10% were resistant to erythromycin, with considerable intercountry variation. All S. pneumoniae and 99.8% of H. influenzae isolates were susceptible to telithromycin using breakpoints proposed to the NCCLS (相似文献   

Antimicrobial susceptibility of viridans group streptococcal blood isolates to eight antimicrobial agents

A total of 155 viridans group streptococci blood culture isolates identified by the Rapid ID32 Strep system were tested for their minimum inhibitory concentrations (MICs) to penicillin, amoxicillin, ceftriaxone, erythromycin, clindamycin, rifampicin, vancomycin and teicoplanin using the E-test. The following species were identified: S. oralis (n = 67), S. mitis (n = 66), S. sanguis (n = 7), S. salivarius (n = 5), S. parasanguis (n = 4), S. gordonii (n = 3) and S. mutans (n = 3). S. oralis and S. mitis demonstrated the highest levels of resistance to the agents tested. There were 27% of S. oralis isolates resistant to pencillin, 51% resistant to erythromycin and 6% resistant to clindamycin. For S. mitis 11% were resistant to penicillin, 40% resistant to erythromycin and 3% resistant to clindamycin. Penicillin resistant isolates (MIC > or = 2 mg/l) also demonstrated decreased susceptibility to other antimicrobial agents tested in this study. High level resistance (MIC > or = 2 mg/l) to ceftriaxone was found in 12 isolates. The isolates identified as ceftriaxone resistant comprised S. oralis (n = 7), S. mitis (n = 4) and S. parasanguis (n = 1). This study has highlighted the difference in susceptibility between different species of viridans group streptococci. These findings are of concern in the light of spread of antibiotic resistance genes from S. oralis and S. mitis to the more invasive pneumococcus.