Antimicrobial resistance in N’Djamena (Chad): Four-year experience of the French Forward Medical and Surgical Team engaged in the “Barkhane Operation”

ObjectivesKnowledge of local antimicrobial resistance (AMR) patterns is required for effective empirical treatment of bacterial diseases. Very little is known about current resistance patterns of common pathogenic bacteria in the African region and particularly in the Sahel region. We aimed to describe the local bacterial epidemiology and to determine whether French recommendations for empirical treatment could be implemented.Patients and methodsWe performed a single-center observational study. Data was collected retrospectively from the Forward Medical and Surgical Center (FFMSC) bacterial database from January 2015 to December 2018. All bacteriological analyses, negative or positive, were included.ResultsA total of 2194 samples were analyzed. Infectious diseases were urinary tract infections (20.8%), bone and joint infections (20.4%), skin infections of chronic wounds (13.4%), soft tissue abscesses (13%), and gastroenteritis (10.8%). The most frequent infections were enterobacterial infections (43.6%) and staphylococcal infections (31.1%). The prevalence of AMR was 32.1%. Significantly more ESBL-producing bacteria (41.3%) were observed in the Chadian population than in the French population in N’djamena (6.3%) (P < 0.001).ConclusionsWe reported a high rate of ESBL-producing bacteria in N’Djamena. The use of empirical antibiotic therapies in the FFMSC may thus be questioned: French recommendations cannot be implemented in such setting and the use of carbapenems or new anti-ESBL antibiotics should be considered. Prospective studies are required to conclude.     

儿童细菌性肺炎的病原菌及耐药分析

目的了解医院临床儿童细菌性肺炎的病原菌分布、药敏率,为儿童细菌性肺炎的诊疗提供依据。方法应用K-B纸片扩散法测试细菌对抗菌药物的敏感性,产超广谱β-内酰胺酶(ESBLs)确证试验检测用双纸片扩散法,应用聚合酶链式反应(PCR)法检测铜绿假单胞菌的ESBLs基因亚型。结果分离的75株病原菌主要有:大肠埃希菌、肺炎克雷伯菌、阴沟肠杆菌、铜绿假单胞菌、金黄色葡萄球菌,检出革兰阴性菌62株,占82.7%,检出较高的为大肠埃希菌、肺炎克雷伯菌、阴沟肠杆菌、铜绿假单胞菌,分别占28.0%、18.7%、14.7%、13.3%;检出革兰阳性菌13株,占17.3%,均为金黄色葡萄球菌;75株细菌对包括青霉素、氨苄西林、头孢唑林在内的多种抗菌药物耐药,对头孢他啶、头孢噻肟耐药率相对较低;ESBLs确证试验共检出24株产ESBLs细菌,检出率为32.0%;铜绿假单胞菌的ESBLs基因亚型为多药耐药CTX-M-14、TEM或CTX-M-14、CTX-M-3的菌株。结论医院临床分离儿童细菌性肺炎的病原菌均有耐药现象,产ESBLs菌有一定程度的流行。     

碳青霉烯类耐药肺炎克雷伯菌感染39例

目的 探讨碳青霉烯类耐药肺炎克雷伯菌(carbapenem-resistant Klebsiella pneumoniae,CRKP)感染的临床特点、易感因素及防治措施.方法 对2006年7月至2008年7月在浙江大学医学院附属第二医院不同病区住院期间分离和培养到CRKP且临床证实为医院感染的39例患者进行回顾性调查分析.结果 39份CRKP阳性标本中,痰标本22份,占56.4%,CRKP感染者平均年龄为64.0岁,平均住院时间达80.8 d,36例2周内曾入住ICU,其中以脑科ICU比例最高,意识障碍者26例,38例留置导尿,34例留置中心静脉导管,32例行机械通气,30例行气管插管,27例(69.2%)合并其他细菌感染,8例合并真菌感染.病情恶化及死亡18例,占46.2%.在培养到CRKP前,27例(69.2%)患者更换超过4种抗菌药物,使用最多的为β-内酰胺酶抑制剂合剂和碳青霉烯类抗菌药物.结论 CRKP感染多发生在老年及长时间住院的患者中,以ICU患者居多,各种侵入性操作可增加其感染概率.     

血液科患者感染病原菌种类及耐药性分析

目的了解南方医科大学南方医院血液科患者分离病原菌种类及耐药性,为合理使用抗菌药物提供依据。方法细菌鉴定和药敏试验采用BD Phoenix100仪器。念珠菌利用显色平板鉴定和K-B法进行药敏试验。数据分析用WHONET5.6软件。结果血液科患者分离病原菌中最常见的为大肠埃希菌、肺炎克雷伯菌、铜绿假单胞菌、屎肠球菌和粪肠球菌。大肠埃希菌和肺炎克雷伯菌产超广谱β-内酰胺酶比例分别为56.1%和33.6%。金黄色葡萄球菌、溶血葡萄球菌和表皮葡萄球菌甲氧西林耐药率分别为20.0%、88.0%和91.5%。革兰阴性杆菌中耐药率较低的为亚胺培南、美罗培南、阿米卡星、头孢哌酮/舒巴坦、哌拉西林/他唑巴坦。革兰阳性球菌对替考拉宁和利奈唑胺的敏感率均为100.0%,葡萄球菌属对万古霉素的敏感率也为100.0%。念珠菌对临床常用抗菌药物的耐药率均低于7.0%。结论南方医科大学南方医院血液科患者分离病原菌耐药率较高,应加强抗菌药物的合理使用,以降低耐药率。     

Frequency of Beta-Lactamase Antibiotic Resistance Genes in Escherichia Coli and Klebsiella pneumoniae

BackgroundThis cross-sectional study was performed on isolates of Klebsiella pneumoniae, and E.coli from clinical specimens of patients admitted to Sayyad Shirazi Hospital by census sampling method in 2019. Antibiogram testing was performed using the disk diffusion method as defined by the Clinical and Laboratory Standards Organization for performing this test. Finally, the abundance of genes was evaluated by PCR using specific primers. Frequency, percentage, mean±SD were used to describe the data. Chi-square and Fisher''s exact tests were used to compare the presence and absence of the studied genes alone and in the presence of each other.ResultThis study was performed on 130 positive samples, isolated from 32 (24.6%) males and 98 (65.4%) females with a mean age of 43.78 ± 21.72. From the total number of 130 isolates, 84 (64.6%) consisted of E.coli, and 46 (35.4%) were Klebsiella. Most of the cultures were urine and vaginal (61.5%). The highest antibiotic resistance in isolates was cephalexin and cefazolin (67.9% in E.coli & 63% in Klebsiella). Colistin was identified as the most effective antibiotic (100%) in both. AMPC extendedspectrum β-lactamase genes were present in 40 (30.8%) isolates. The highest frequency about the gene pattern of AMPC positive β-lactamase bacteria was correlated to DHA, FOX, and CIT genes, while none of the samples contained the MOX β-lactamase gene. E.coli and Klebsiella beta-lactamase-producing AMPC isolates were also significantly correlated with antibiotic resistance to the cephalosporin class (P <0.05).ConclusionThis study indicated a high percentage of resistance to third and fourth generation cephalosporins. Hence, careful antibiogram tests and prevention of antibiotic overuse in infections caused by AMPC-producing organisms and screening of clinical samples for the resistance mentioned above genes and providing effective strategies to help diagnose and apply appropriate treatments and change antibiotic usage strategies can partially prevent the transmission of this resistance.     

儿童各类标本中产超广谱β-内酰胺酶菌危险因素研究

目的 研究儿童各类标本中产超广谱β-内酰胺酶菌(ESBLs)的危险因素,为临床预防与控制产ESBLs菌株的传播和流行提供参考依据.方法 随机抽取山西省儿童医院2007年1月-2009年4月各类标本中ESBLs阳性和阴性病例各100份进行病例对照研究.结果 单因素分析结果显示,男性、年龄<1岁、有既往病史、内科、肺炎、医院感染、入院前使用抗菌药物均是ESBLs的危险因素;入院时白细胞数偏高和中性粒细胞百分比偏高是ESBLs的保护因素;ESBLs与手术、输血及其他侵入性操作的相关性未见统计学意义;多因素非条件Logistic回归显示男性、有既往病史、医院感染、入院前使用抗菌药物、内科是产ESBLs的危险因素,有肛管是保护因素.结论 提高对具有相关危险因素患儿的细菌学送检率,对预防与控制ESBLs细菌的传播和流行有重要意义.     

CTX-M-38型超广谱β-内酰胺酶的表达、定位及其抗药活性分析

目的:体外表达CTX-M-38型超广谱β-内酰胺酶(ESBL),并明确表达产物的分布及其抗药活性.方法:收集2006-2007年分离的产ESBL大肠埃希菌46株,采用PCR技术克隆目的基因,基因重组技术构建pET28a-CTX-M-38质粒,用BL21大肠杆菌作为宿主菌进行表达,测定培养基上清及菌体裂解液酶活性检测所表达ESBL的分布;采用液体稀释法检测所表达ESBL抗药活性.结果:PCR扩增条带约在900 bp位置处;测序结果与预测CTX-M-38相一致;菌体裂解液抗药活性较强;转化子对青霉素类、头孢一代、二代及多数三代药物均耐药;对碳青酶烯类药物稳定敏感;对头孢他啶及氨曲南体外敏感;对酶抑制剂除哌拉西林/他唑巴坦敏感外,其余表现为耐药;对庆大霉素、美满霉素、环丙沙星及左氧氟沙星亦具有耐药性.结论:CTX-M-38型ESBL表达成功,表达产物主要分布于表达菌体内,具有广泛抗药活性.     

PER-1型超广谱β-内酰胺酶在铜绿假单胞菌中的流行分析

目的调查超广谱β-内酰胺酶（ESBLs）以及具碳青霉烯酶活性的OXA酶在铜绿假单胞菌中的流行状况。方法针对1997—2003年间本院收集的具临床意义的铜绿假单胞菌,采用8对通用ClassA和ClassD类超广谱β-内酰胺酶基因引物对其进行聚合酶链反应（PCR）,根据结果再进行长片段引物扩增和序列测定;对PCR扩增阳性株与受体菌利福平耐药铜绿假单胞菌PU21行转移接合试验;采用琼脂平皿稀释法测定所有受试菌的MIC;运用脉冲场凝胶电泳（PFGE）方法确定菌株间的遗传相关性。结果47株临床分离铜绿假单胞菌中共检出28株PER阳性菌株,经部分长片段产物序列测定证实为PER-1型超广谱β-内酰胺酶;该产酶菌株经转移接合试验无法将耐药性传递给受体菌;药敏结果显示耐药表型与基因型间有很好相关性,对哌拉西林和头孢他啶高度耐药,同时产酶株对亚胺培南呈现100％的耐药性,对哌拉西林-三唑巴坦亦有一定程度的耐药;PFGE结果显示各菌株间存在垂直传播或有较近遗传相关性。结论本院存在产PER-1型ESBLs铜绿假单胞菌的流行。     

重症监护病房铜绿假单胞菌β-内酰胺酶检测与耐药特征分析

目的了解上海市长宁区中心医院重症监护病房铜绿假单胞菌β-内酰胺酶产生情况,为临床治疗及控制医院感染提供依据。方法用K-B法进行常规药敏试验,筛选出78株多重耐药铜绿假单胞菌,用改良三维试验检测各种β-内酰胺酶,同时用2-巯基丙酸抑制试验检测金属酶。结果 78株铜绿假单胞菌中产超广谱β-内酰胺酶(ESBLs)5株(6.4%)、产碳青酶烯酶(AmpC)31株(39.7%),17株同时产ESBLs和AmpC(21.8%),金属酶筛选出12株(15.4%)阳性。结论该院铜绿假单胞菌β-内酰胺酶以AmPC酶为主,临床应根据药敏试验结果,合理选用抗生素,以减少耐药菌株产生和控制医院感染。     

Should the patients colonized with extended-spectrum beta-lactamase-producing Gram-negative bacilli (E-GNB) coming to hospital from the community with pneumonia get anti-E-GNB active empirical treatment?

Extended-spectrum beta-lactamases are responsible for resistance of Gram-negative bacilli to several beta-lactam antibiotics, including those prescribed for treatment pneumonia. To evaluate the importance of colonization with E-GNB for the choice of empirical treatment we performed a retrospective case-control study including 156 patients, hospitalized for treatment of pneumonia from 2009 through 2013. Empirical treatment success and in-hospital survival were significantly lower in patients colonized with E-GNB compared to non-colonized (p = 0.002, p = 0.035). When comparing subgroups of colonized patients, treatment success was significantly lower in patients who were colonized with E-GNB resistant to empirical antibiotic (p = 0.010), but not in those colonized by E-GNB susceptible to empirically given antibiotic (p = 0.104). Difference in in-hospital mortality was insignificant in both subgroups (p = 0.056, p = 0.331). The results of study suggest that an anti-E-GNB active antibiotic should be used for empirical treatment of pneumonia in E-GNB colonized patients.