Pantoea agglomerans pneumonia in a heart–lung transplant recipient: case report and a review of an emerging pathogen in immunocompromised hosts

A. Shubov, P. Jagannathan, P. V. Chin‐Hong. Pantoea agglomerans pneumonia in a heart–lung transplant recipient: case report and a review of an emerging pathogen in immunocompromised hosts. Transpl Infect Dis 2011. All rights reserved Abstract: Pantoea agglomerans is a gram‐negative rod that is frequently found on the exterior of many plants, fruits, vegetables, and in soil, and it is used as a biopesticide in the agriculture industry. Recent reports have implicated P. agglomerans in systemic infections of immunocompromised hosts and neonates, as well as more localized infections in healthy hosts. P. agglomerans as a cause of hospital‐acquired pneumonia has not been well characterized. We report a case of P. agglomerans pneumonia in a heart–lung transplant recipient following transplantation. The organism was susceptible to multiple antimicrobial agents and treated successfully with ertapenem. We review the patient's course and the relevant literature, and discuss implications for the future.     

新生儿病房阴沟肠杆菌感染及药敏结果分析

目的 回顾性分析新生儿病房阴沟肠杆菌感染情况及药敏结果,为有效防治阴沟肠杆菌感染提供依据.方法 对2008年2 - 7月新生儿病房送检的血、痰、尿、大便、脑脊液及脐带分泌物等细菌培养阳性标本进行分析,并采用K-B 纸片扩散法检测药物敏感性,通过改良酶提取物头孢西丁和头孢曲松三维试验检测AmpC β2内酰胺酶(AmpC酶)和产超广谱β2内酰胺酶(ESBLs),分析不同种类阴沟肠杆菌的药敏结果.结果 院内感染47例,占所有病例的7.4%,所有标本中共检出各类细菌395株,肺炎克雷伯细菌、大肠埃希菌及金黄色葡萄球菌位列前3位(分别占43.2%,10.6%和8.6%),阴沟肠杆菌14株(3.54%),排第8位.标本来源为痰液、血液、尿液和脐带分泌物,分别占64.2%、14.3%、14.3%和7.14%;单产AmpC酶、产AmpC酶 + ESBLs、单产ESBLs的检出率分别为21.4%、14.2%、14.2%;产酶株的耐药性明显高于非产酶株,全部菌株对亚胺培南敏感.结论 阴沟肠杆菌在新生儿病房感染中并非常见细菌,其主要引起呼吸道、血液、尿路和脐部感染,产AmpC酶和ESBLs在阴沟肠杆菌中较为常见,在未明确药敏之前,可考虑将亚胺培南列为经验用药,及早有效治疗新生儿阴沟肠杆菌院内感染.     

Extended-spectrum β-lactamase-producing enterobacteriaceae causing nosocomial infections in Mexico. A retrospective and multicenter study

Background and Aims

Extended-spectrum β-lactamase (ESBLs) production is still the most frequent mechanism of resistance to cephalosporins in gram-negative bacteria. The aim of the study was to identify the types of ESBL-producing Enterobacteriaceae clinical isolates causing nosocomial infections in Mexico.

Methods

ESBL production was performed using a disk diffusion method. The MIC for several antibiotics was performed by agar dilution on Mueller-Hinton. PFGE typing was carried out on all enterobacteria assayed. The β-lactamase pattern was obtained by IEF and bioassay. Genes of β-lactamases were amplified by PCR with specific primers and products were sequenced and analyzed using informatics programs. Plasmid isolation and conjugation experiments were carried out using standard methodologies.

Results

There were 134 isolates of Enterobacteriaceae included from a retrospective and multicenter study that included eight Mexican hospitals from 1999 to 2005. The most prevalent species were K. pneumoniae (56%), Enterobacter cloacae (29%), and Escherichia coli (15%). Molecular analysis identified the underlying endemic and polyclonal spread of enterobacterials in each hospital. The most frequent ESBLs identified were SHV-type (84%), TLA-1 (11%), and CTX-M-15 (5%). Successful matings were detected in 68.4% (71/104) isolates.

Conclusions

ESBL-producer K. pneumoniae remains the most frequent bacterial species obtained in nosocomial infections. The SHV-type and TLA-1 ESBLs were disseminated in most hospitals analyzed and CTX-M-15 was emerging in one of the studied hospitals. This work highlights the proper use of antibiotics to avoid the selection of these types of multiresistant bacteria.     

Isolation of Rhizobacteria from Jatropha curcas and characterization of produced ACC deaminase

Decreased levels of ACC (1-aminocyclopropane-1-carboxylic acid) result in lower levels of endogenous ethylene, which eliminate the potentially inhibitory effects of stress-induced higher ethylene concentrations. It is worth noting the substantial ability of the bacterial species to colonize different environments, including taxonomically distinct plants cultivated in distantly separated geographical regions. For example, Enterobacter cloacae, designated as MSA1 and Enterobacter cancerogenus, designated as MSA2 were recovered from the rhizosphere of Jatropha in the present work. This study first time confirms the ACC deaminase activity in the Enterobacter cancerogenus on the preliminary basis. Several bacterial plant growth-promoting mechanisms were analyzed and detected like phosphate solubilization, siderophore production, IAA production, GA(3) (gibberellic acid) production and ACC deaminase activity in the isolated cultures. Isolates were grown until exponential growth phase to evaluate their ACC deaminase activity and the effect of pH, temperature, salt, metals and substrate concentration after the partial purification of enzyme by ion exchange chromatography. The FOURIER TRANSFORM INFRARED (FT-IR) spectra were recorded for the confirmation of α-ketobutyrate production. By using lineweaver Burk plot K(m) and V(max) value for ACC deaminase of both the organism was calculated in the different fractions. In this work, we discuss the possible implications of these bacterial mechanisms on the plant growth promotion or homeostasis regulation in natural conditions.     

表型筛选试验检测阴沟肠杆菌产β-内酰胺酶及耐药分析

目的:对近年耐三代头孢的阴沟肠杆菌进行β-内酰酶(主要是ESBLs与AmpC酶)监测以进行流行病学调查,同时作相关统计以指导实验室检测及临床用药。方法:收集来自各种标本对三代头孢耐药的阴沟肠杆菌45例表型筛选试验检测ESBLs与AmpC酶。结果:产ESBLs 42株,占93.33%,产AmpC酶8株,占17.78%,两种酶均产的有8株。结论:对三代头孢耐药的阴沟肠杆菌主要产ESBLs,体外实验对亚胺培南敏感率为97.66%,对其他抗菌药物敏感性差。     

阪崎肠杆菌新疆分离株基因同源性分析

目的 分析6株阪崎肠杆菌新疆分离株基因同源性.方法 采用试剂盒提取DNA,分别以Esak2、Esak3、Esakr、Esakf为引物,扩增16SRNA目的基因片段,测序后通过BLAST与标准株的基因片段进行比对,判断同源性.结果 阪崎肠杆菌新疆分离株在同源性上分别与5株国际标准株基因同源,最大相似度达到100%,其中IQCC10403-26、IQCC10418与EU675663.1同源,但相似度有差异.结论 6株阪崎肠杆菌新疆分离株具有不同的同源性.可通过基因同源性来区分阪崎肠杆菌,不再局限于表型分型.     

129株阴沟肠杆菌感染分布与耐药分析

目的探讨医院阴沟肠杆菌感染分布及耐药性,便于指导临床科学合理用药提供依据。方法采用法国生物梅里埃公司生产的全自动微生物分析系统对临床分离的阴沟肠杆菌进行鉴定和药敏实验,并分析其结果。结果 129株阴沟肠杆菌,菌株来源主要为痰占63.75%、尿液占11.63%和其他分泌物。结论阴沟肠杆菌主要引起呼吸道、泌尿道感染,耐药率高,临床应根据药敏结果合理选用抗菌药物。     

TEM-24 extended-spectrum β-lactamase-producing Enterobacter aerogenes: long-term clonal dissemination in French hospitals

Objective To investigate interstrain relatedness of TEM-24-producing Enterobacter aerogenes clinical strains isolated between 1993 and 1998 in 10 French hospitals from nine areas by pulsed-field gel electrophoresis (PFGE) and plasmid patterns.
Methods Fifteen TEM-24 - producing strains and a set of 16 control strains having various other antibiotic resistance phenotypes were genotyped by PFGE. Plasmid DNA from TEM-24 - producing strains and transconjugants was analyzed .
Results Analysis of Xba I macrorestriction patterns revealed only minor variations, and showed that all 15 TEM-24 - producing strains were closely related. Some isolates originating from distant areas had indistinguishable patterns . According to their clustering correlation coefficients, they were also genomically distant from the control strains . Two plasmid patterns were observed in TEM-24-producing strains, one of them in 13 of the strains. Large plasmids of 85 kb encoding TEM-24 β-lactamase were present in all isolates and, in all except one strain, could be transferred with high frequency by conjugation .
Conclusions These results confirm that the spread of the TEM-24 extended-spectrum β-lactamase in France was essentially due to the dissemination of a single clone .     

Drug-resistance mechanisms and prevalence of Enterobacter cloacae resistant to multi-antibiotics

The main drug-resistance mechanism of gram-negative bacteria is producing β-lactamases. Two kinds of enzymes cause drug resistance by hydrolyzing oxyimino-cephalosporins and aztreonam: one is chromosomally encoded AmpC β-lactamases, the other is plasmid-mediated extended-spectrum β-lactamases (ESBLs). Enterobacter cloacae can produce both of them, so that these strains are seriously resistance to many antibiotics. In order to study the main drug-resistant mechanism in Enterobacter cloacae, PCR and nucleotide sequencing were performed on 58 multidrug resistant strains.