Extended-spectrum Beta-lactamases Encoding Genes among Salmonella Enterica serovar Typhi Isolates in Patients with Typhoid Fever from four Academic Medical Centers in Lagos, Nigeria

ABSTRACT Background: There is scarce information about the occurrence of extended-spectrum β-lactamases (ESBLs) in Salmonella enterica serovar Typhi (S. Typhi) from patients with typhoid fever. Objective: To study the antimicrobial resistance and ESBL encoding genes among S. Typhi isolates in aforesaid patients from Lagos, Nigeria. Methods: S. Typhi isolates were collected from blood samples of typhoid fever patients from 4 academic medical centers in Lagos, Nigeria. The identification of isolates and their antibiotic susceptibility testing were performed by standard bacteriological techniques and disc diffusion method, respectively. The production of ESBLs was investigated using combination disk test (CDT) and polymerase chain reaction (PCR). Results: A total of 27 S. Typhi isolates was collected. All isolates were susceptible to imipenem and nitrofurantoin. Fifteen (55.6%) isolates were multidrug-resistant (MDR). The CDT test showed 11 (40.7%) ESBL producer isolates. However, the PCR revealed a higher occurrence rate for ESBL producers (66.7%, n = 18/27). The ESBL genes were as follows: blaCTX-M (37.0%, n = 10/27), blaSHV (18.5%, n = 5/27), and blaTEM (44.4%, n = 12/27). All ESBL positive S. Typhi isolates were MDR. Conclusions: This study showed the emergence of ESBL-harboring S. Typhi in patients with typhoid fever from Nigeria.

Bacterial surveillance and drug resistance analysis of ESBLs Enterobacteriaceae produced by female vaginal secretions / 国际检验医学杂志

Objective In order to understand the distribution and drug resistance of the extended-spectrumβ-lactamase-producing (ESBLs) Enterobacteriaceae in female vaginal secretions and to provide the basis for clinical treatment.Methods 939 strains of Enterobacteriaceae isolated from female vaginal secretions were collected from Obstetrics and Gynecology Hospital of Fudan University from January 2014 to December 2017.The strain identification and drug sensitivity test of VITECK 2 Compact-totally automatic bacterial identification analyzer were used to analyze the detection rate and drug resistance of ESBLs Enterobacteriaceae.Results 257 strains of ESBLs-producing strains were detected in 939 strains of Enterobacteriaceae with a detection rate of 27％, including 220 Escherichia coli, 34 Klebsiella pneumoniae, 2 Stink-nose Klebsiella and 1 strain of Acidogenic Klebsiella.ESBLs Escherichia coli and Klebsiella pneumoniae were all resistant to Ampicillin and Cefazolin, and to Ceftazidime, Nitrofurantoin, SMZ, Amikacin, Ciprofloxacin, Gentamicin, tobramycin, Ampicillin/Sulbactam, Ceftriaxone, Ertapenem, Piperacillin/Tazobactam, Aztreonam, Cefepime, Levofloxacin the drug resistance rates of were 36％and 44％, 2％ and 41％, 67％ and 68％, 2％ and 15％, 58％ and 38％, 51％ and65％, 14％and 26％, 65％and 76％, 99％and 97％, 0％and 29％, 0％and 3％, 50％and 65％, 26％and 18％, 57％ and 32％, but they are all sensitive to Imipenem and Cefotetan.Conclusion The inicdence of ESBLs Enterobacteriaceae in female vaginal secretions is high, and Imipenem, Cefotetan, Piperacillin/Tazobactam have high antibacterial activity, which can be used as the experience of initial treatment.

Study of pandrug and heavy metal resistance among E. coli from anthropogenically influenced Delhi stretch of river Yamuna

Abstract Escalating burden of antibiotic resistance that has reached new heights present a grave concern to mankind. As the problem is no longer confined to clinics, we hereby report identification of a pandrug resistant Escherichia coli isolate from heavily polluted Delhi stretch of river Yamuna, India. E. coli MRC11 was found sensitive only to tobramycin against 21 antibiotics tested, with minimum inhibitory concentration values >256 µg/mL for amoxicillin, carbenicillin, aztreonam, ceftazidime and cefotaxime. Addition of certain heavy metals at higher concentrations were ineffective in increasing susceptibility of E. coli MRC11 to antibiotics. Withstanding sub-optimal concentration of cefotaxime (10 µg/mL) and mercuric chloride (2 µg/mL), and also resistance to their combinatorial use, indicates better adaptability in heavily polluted environment through clustering and expression of resistance genes. Interestingly, E. coli MRC11 harbours two different variants of blaTEM (blaTEM-116 and blaTEM-1 with and without extended-spectrum activity, respectively), in addition to mer operon (merB, merP and merT) genes. Studies employing conjugation, confirmed localization of blaTEM-116, merP and merT genes on the conjugative plasmid. Understanding potentialities of such isolates will help in determining risk factors attributing pandrug resistance and strengthening strategic development of new and effective antimicrobial agents.

Detection Of Esbl-Producing Escherichia Coli And Klebsiella Pneumoniae In Patient Suffering With Symptomatic Urinary Tract Infection In Tertiary Care Hospital.

Aim and objectives: This study is to determine the prevalence of Extended spectrum beta-lactamases (ESBLs) in urinary isolates. To compare different phenotypic methods for ESBL detection and to evaluate the antibiotic resistance patterns among ESBL producing urinary Escherichia coli. Methodology: rd Urinary isolates of E.coli that were resistant to at least one of 3 generation cephalosporins (cefotaxime, ceftazidime) were screened and tested for ESBLproduction using the Double disc diffusion test (DDDT), quantitative E-strip method and Automated Vitek-2. Result: A total of 341 Klebsiella pneumoniae and Escherichia coli isolates were screened from patients with symptomatic UTI. 207 (60.7%) Escherichia coli, 134 (39.2%) Klebsiella pneumonia. ESBL production was detected in 48.8% and for 161 screening test positive E. coli, ESBL production was detected in 40%

Epidemiology of Extended-Spectrum Beta-Lactamases (ESBLs)-Producing Bacteria in Different Regions in Saudi Arabia: A Systematic Review

Recently, a number of Saudi studies have indicated the emergence of a new genetic mutation in gram-negative bacteria (GNB) strains, particularly in extended spectrum beta-lactamase (ESBL) producing isolates, which accounts for about 8% to 38% of the total GNBs detected at Saudi hospitals. ESBLs are enzymes identified in GNB and have ability to resist beta lactam antimicrobial agents by breaking down the lactam ring. To ensure the objectiveness of this study, this paper presents most of the published studies on ESBL infection in Saudi Arabia (available online). ESBL-producing bacteria were detected using disk diffusion methods, dilution methods, double-disc synergy test, E-test strip and molecular detection methods. Risk factors contributing to the spread of ESBL infection include renal disease, diabetes, age, gender, hospital admission and previous exposure to antibiotics. CTX-M, TEM and SHV genotypes are the most common in the studies that have been performed in Saudi hospitals. Imipenem, meropenem, tigecycline and nitrofurantoin are still the best options to treat the ESBL infection. Appropriate infection control policies should be applied to reduce the risk factors of such infections.

A non-surgical rat model of foreign body-associated urinary tract infection with ESBLs-producing E.coli injection / 医学研究生学报

Objective At present, the traditional model of urinary tract infection is not only complex in operation process but also easy to be infected, and the model with simple transurethral bacterial injection is not stable enough. This study established a rat model of foreign body-associated urinary tract infection. A spiral polyethylene tube (PT) was placed transurethrally into the bladder by transurethral inoculation with extended-spectrum β-lactamases-producing Escherichia coli (ESBLs E.coli).Methods SD female rats were randomly divided into blank control group, no foreign body groups at 7d and 14d, foreign body groups at 7d and 14d. ESBLs E.coli was injected transurethrally by foreign body into the bladder in foreign body groups. The same volumes of ESBLs E.coli and sterile saline were injected respectively in no foreign body and blank groups. Examination was made on bilateral renal gravity index, the numbers of white blood cells and neutrophils, the bacteriological and pathological changes in urine and kidney.Results The bilateral renal gravity index, the percentage of neutrophils and and the positive rates of renal and urine bacteria culture in foreign body groups at 7d and 14d were significantly higher than those in blank control group and no foreign body groups(P＜0.05). The number of white blood cells in foreign body group at 7d was significantly higher than those of blank control and no foreign body group(P＜0.05). The positive rates of renal and urine bacteria culture were 100% in the foreign body groups at 7d and 14d. The positive rate of urine bacteria culture in no foreign body at 7d was 33.3%. Under the light microscope, there were inflammatory changes in the kidney and bladder tissues of the rats in foreign body groups, and a few fibrous tissues were formed around glomeruli in foreign body group at 14d.Conclusion The establishment of a highly successful and stable rat model of urinary tract infection can be successfully achieved by injection of ESBLS E.coli through transurethral foreign body placed in bladder.

Analysis of Clinical Distribution and Drug Resistance of Non-sputum Specimen AmpC Enzyme-producing Enterobacter cloacae in a Hospital during 2011-2017 / 中国药房

OBJECTIVE:To provide reference for rational drug use and hospital infection control. METHODS:AmpC enzyme-producing Enterobacter cloacae were isolated from non-sputum specimen of a hospital during Jan. 2011-Oct. 2017. Drug sensitivity test was conducted by using MIC. The situation of AmpC enzyme production was confirmed by three dimensional test, and that of ESBLs-producing stain was detected with double-disk synergy test. RESULTS:There were 546 strains of AmpC enzyme-producing E. cloacae isolated from non-sputum specimen of the hospital,accounting for 4.80% of non-sputum specimen (546/11 375)and 38.97% of E. cloacae(546/1 401). Top 3 non-sputum samples in the list of detection rate were wound secretion (27.29%),midstream urine(25.82%)and blood(21.79%),and the departments with high detection rate were ICU(22.89%), neurosurgery department(18.68%)and general surgery department(16.67%). Resistance rate of AmpC enzyme-producing E. cloacae to most commonly used antibiotics was higher than 40%. There was statistical significance in resistant rate of the bacteria to ceftriaxone, cefotaxime, gentamicin, nitrofurantoin, levofloxacin, piperacillin/tazobactam, cefoperazone, ceftazidime,cefepime,tobramycin and minocycline among different years (P<0.05). The resistant rate to imipenem and meropenem was lower than 2%. Among 546 strains of AmpC enzyme-producing E. cloacae,68 strains of ESBLs were detected,and detection rates were 5.77%,6.06%,8.70%,10.26%,13.79%,17.35%,18.75% during 2011-2017. CONCLUSIONS:AmpC enzyme-producing E. cloacae are mainly isolated from samples as wound secretion and midstream urine,and mainly come from ICU and neurosurgery department. The drug resistance of the bacteria is severe,and drug resistance of the bacteria to antibiotics as β-lactams and quinolones is increased significantly. The detection rate of ESBLs-producing strain increases year by year. The bacteria are sensitive to carbapenems antibiotics,which can be regarded as first choice. It is necessary to strengthen drug resistance and enzyme production monitoring of AmpC enzyme-producing E. cloacae,select antibiotics combined with results of drug sensitivity test so as to prevent or delay the rapid increase of its resistance rate.

Pharmaceutical Care for a Case of ESBLs Producing Klebsiella pneumoniae Severe Pneumonia / 中国药房

OBJECTIVE: To probe the role of clinical pharmacists in drug use of patients with severe pneumonia. METHODS: Clinical pharmacists participated in the treatment for a patient with ESBLs producing Klebsiella pneumoniae severe pneumonia. The patient was given cefoperazone tazobactam combined with moxifloxacin and ganciclovir initially. Clinical pharmacists suggested stopping cefoperazone tazobactam and moxifloxacin and additionally using meropenem according to the elevation of hemogram infection indexes; suggested stopping ganciclovir and continuously using meropenem according to the results of sputum culture; suggested providing cefoperazone sulbactam de-escalation sequential therapy for ESBLs producing Klebsiella pneumoniae and stopping cefoperazone sulbactam and azithromycin according to clinical symptoms of the patient. RESULTS: The physicians adopted the suggestions of clinical pharmacists. After treatment, body temperature and lab indexes of the patient recovered to normal; the result of sputum culture turned to negative. Chest CT showed that the infection focus was obviously absorbed compared to before. After discharged from hospital and followed up, the patient was found to have a good prognosis. CONCLUSIONS: Through actively participating in drug therapy, based on lab indexes and results of sputum culture, clinical pharmacists provide pharmaceutical care and adjust medication plan to improve treatment rate of patients with severe pneumonia and the safety and effectiveness of drug treatment, be of great significance to promote the rational use of antibiotics.

Prevalence of Methicillin Resistant Staphylococcus aureus, Extended Spectrum of Lactamase Producing Escherichia coli and Klebsiella Spps Isolates from ICU Patients at Tertiary Care Hospital, Aurangabad

Background and Objectives The microbial surveillance of intensive care units (ICUs) for multidrug resistant bugs is required for management of ICU patients. The objectives of the study were to find out the prevalence and antimicrobial susceptibility pattern of methicillin-resistant Staphylococcus aureus (MRSA) and extended spectrum of beta lactamase (ESBLs) producing Escherichia coli and Klebsiella isolates in clinical samples from ICU patients. Methods A total of 464 clinical samples were received in the department of microbiology for culture and sensitivity from ICU patients and were processed as per standard protocol. Detection of MRSA and ESBLs was carried out by using CLSI guidelines. Results A total of 164 were positive for culture. A total of 196 isolates were isolated, among that 57 were S. aureus and 34 were E. coli, 51 were Klebsiella spp. and remaining 54 isolates were other gram negative and gram positive organisms. Out of 57 S. aureus, 23 (42.6%) were detected as MRSA. 41.2% of E. coli and 45.1% of Klebsiella spp. were ESBL producers. The antibiotic sensitivity rates were found higher in MRSA than MSSA and also same in non-ESBL-producing and ESBL-producing strains which were statistically significant (p-value). Conclusion The maximum ESBL producing isolates were Klebsiella. spp than E. coli. Vancomycin and linezolid remains a drug of choice for MRSA. For ESBL-producing E. coli and Klebsiella, carbapenems remain the drug of choice. Institutional antimicrobial surveillance and proper infection control practices are essential to prevent and control multidrug resistant bugs in ICUs and hospital.

Gene typing of ESBLs-producing third-generation cephalosporins-resistant Shigella in Ningbo, China / 中国人兽共患病学报

We investigated the third-generation cephalosporins-resistant Shigella and its genotype in Ningbo,China,providing a basis for disease prevention and control.Pathogenic bacteria were analyzed by direct isolation combined with enrichment culture isolation.Antimicrobial susceptibility was determined by K-B disk diffusion method and PCR was used for detecting multidrug resistance genes like CTX-M,OXA,TEM and SHV.BLAST analysis was used to determine the genotype.Results showed that 69 strains of third-generation cephalosporins-resistant Shigella were detected by drug sensitivity screening,accounting for 74.19％ of ESBLs Shigella.Drug resistance gene CTX-M(CTM-M-1 and CTM-M-9),OXA and TEM were detected.The detection rate were 79.71％,79.01％ and 26.09％ respectively.With no CTX-M-2 and SHV,DNA sequence alignment showed CTX-M-1 group were mainly of CTX-M-15 type besides seven other types;CTX-M-9 group were mainly of CTX-M-14 type besides six other types;49 strains of OXA and 18 strains of TEM were sequenced to be type 1 (OXA-1 and TEM-1 type).The 21 Shigella strains carrying more than two drug resistance genes accounts for 30.43 ％.Shigella in Ningbo has high third-generation cephalosporins-resistance rate and many kinds of ESBLs enzymes were detected.The mainstream enzyme type was CTX-M,meanwhile they also carried a variety of drug resistance genes,which could bring difficulties to disease prevention and control.The high carrying rate of OXA-1 type suggests that we should pay more attention.The detection rate of group B was higher than that of group D,including not only the phenotype resistance but also the drug-resistance genes;these findings will be useful in the study of the drug resistance prevalence of Shigella.

Prevalence of plasmid-mediated quinolone resistance genes in Klebsiella pneumoniae strains in pediatrics in China / 中华微生物学和免疫学杂志

Objective To investigate the prevalence of plasmid-mediated quinolone resistance (PMQR) genes among clinical isolates of Klebsiella pneumoniae (K.pneumoniae) in pediatrics.MethodsA total of 131 non-duplicate clinical isolates of K.pneumoniae were collected in the Affiliated Children′s Hospital of Capital Institute of Pediatrics from 2010 to 2012.PMQR genes [qnrA, qnrB, qnrS, aac(6′)-Ⅰb-cr and qepA], mutations in the quinolone resistance-determining region (QRDR) and extended spectrum β-lactamases (ESBLs) genes in those strains were analyzed by PCR.Minimum inhibitory concentrations (MIC) of different antibiotics against those K.pneumoniae strains were determined by broth microdilution method and E-test according to the guidelines issued by the Clinical and Laboratory Standards Institute (CLSI).Transferability of the PMQR genes was examined by conjugation test with the sodiumazide-resistant Escherichia coli J53.Results Among the 131 isolates, 9.92% were resistant to quinolone and 30.5% were positive for PMQR genes, including 6.87% harboring qnrB gene, 22.9% harboring qnrS gene and 4.58% harboring aac(6′)-Ⅰb-cr gene.Neither qnrA-positive nor qepA-positive strain was detected.Among these PMQR genes-positive isolates, 90% were ESBLs-producing strains and two presented mutations in gyrA and parC genes.Conjugation test showed that these PMQR genes could be transferred horizontally and the ciprofloxacin resistance increased 2 to 32 folds in transconjugants.Conclusion This study indicates that the PMQR gene-carrying rate is high in K.pneumoniae strains isolated in paediatrics in China.Most of the PMQR gene-positive strains are also ESBLs-producing strains.The PMQR genes could be transferred horizontally in bacteria.

Analysis on Drug Resistance of Enterobacteriaceae Bacteria to Carbapenems Antibiotics in Our Hospital / 中国药房

OBJECTIVE:To provide reference for rational use of carbapenem antibiotics in the clinic. METHODS:Enterobac-teriaceae bacteria were collected from our hospital during Jan. 2014-Dec. 2015;semiautomatic microbiological assay instrument was used for strain culture,identification and drug sensitive tests. Modified Hodge test and K-B test were adopted to confirm Klebsiella pneumoniae carbapenemases (KPC)-producing and ESBLs-producing drug resistant strains. RESULTS:During 2014-2015,1 035 strains of Enterobacteriaceae bacteria were detected in our hospital,among which there were 732 strains of Escherichia coli,157 strains of K. pneumonia,136 strains of Enterobacter cloacae and 10 strains of Serratia marcescens. Citrobacter freundii was not found. E. coli and K. pneumonia were highly sensitive to amikacin and carbapenems,but slightly sensitive to most cephalosporin. A total of 64 strains of carbapenems-resistant Enterobacteriaceae bacteria(6.18%)were detected,among which there were 31 strains of carbapenems-resistant E. coli(4.23%),30 strains of carbapenems-resistant K. pneumonia(19.11%),1 strain of carbapenems-re-sistant E. cloacae(0.74%)and 2 strains of carbapenems-resistant S. marcescens(20.00%). The samples were mainly from sputum and urine specimens,which were mainly from neonatal department and ICU. Of 64 drug resistant strains,there were 59 KPC-pro-ducing strains (92.19%) and 3 ESBLs-producing strains (4.69%). CONCLUSIONS:E. coli occupies high proportion among En-terobacteriaceae bacteria,and the number of carbapenems-resistant E. coli and carbapenems-resistant K. pneumoniae is in high lev-el. Drug resistance of Enterobacteriaceae bacteria to carbopenems may be associated with KPC and ESBLs producing. Carbapenem antibiotics should be selected rationally in accordance with medication indications and the results of drug sensitivity test.

Characterization of Extended-Spectrum β-Lactamase Genes of Shigella flexneri Isolates With Fosfomycin Resistance From Patients in China

BACKGROUND: The emergence of fosfomycin resistance and extended-spectrum β-lactamase (ESBL) genes is a serious threat to public health and a new challenge in shigellosis treatment. The purpose of this study was to identify fosfomycin resistance and characterize β-lactamase genes in fos-carrying isolates of Shigella flexneri from patients in China. METHODS: A total of 263 S. flexneri isolates were collected from 34 hospitals in the Anhui Province of China during September 2012-September 2015 and screened for fosA3, fosA, and fosC2 by PCR amplification and sequencing. The fos-carrying isolates were then screened for β-lactamase genes. The clonal relationships between fosA3-carrying isolates, the transmissibility of fosfomycin resistance, replicon types of plasmids carrying fosfomycin resistance genes and other associated resistance genes were investigated. RESULTS: Twenty-five of the 263 isolates (9.5%) showed resistance to fosfomycin, and 18 (6.8%) were positive for fosA3. None of the isolates was positive for fosA or fosC2. Seventeen of the isolates carrying fosA3 (94%) were CTX-M producers (seven CTX-M-55, five CTX-M-14, and five CTX-M-123), while three (16.7%) were TEM producers (TEM-1).Sixteen (88.9%) fosA3-carrying isolates exhibited multi-drug resistance. The replicon types of the 13 fosA3-carrying plasmids were IncF (n=13), IncHI2 (n=3), IncIl-Ir (n=2), and IncN (n=1). CONCLUSIONS: Our results indicated that fosA3 could spread through plasmids in S. flexneri isolates, along with the bla(CTX-M) and bla(TEM), which facilitate its quick dispersal. To the best of our knowledge, this is the first report of CTX-M-123-type ESBLs in S. flexneri isolates from patients in China.

Mossambicus tilapia (Oreochromis mossambicus) collected from water bodies impacted by urban waste carries extended-spectrum beta-lactamases and integron-bearing gut bacteria.

Oreochromis mossambicus (Peters 1852) (Tilapia) is one of the most consumed fish globally. Tilapia thrives well in environments polluted by urban waste, which invariably contain antibiotic-resistant bacteria and antibiotic resistance genes (ARGs). Thus, Tilapia surviving in such polluted environments may serve as a potential source for dissemination of ARGs. To investigate this, we isolated bacterial strains from gut of Tilapia found in polluted rivers and lakes near Pune, India, and studied the prevalence of resistance genes bymolecularmethods. A total of 91 bacterial strains were obtained, which include fish pathogens and human pathogens such as Aeromonas hydrophila, Klebsiella pneumoniae, E. coli, Serratia marcescens, Enterobacter spp. and Shigella spp. Overall the prevalence of class 1 integrons, class 2 integrons, extended-spectrum betalactamases (ESBLs) blaCTX-M, blaSHV and aac(6')-Ib-cr gene was 38%, 24%, 38%, 31% and 31% respectively. Forty-two percent of the Enterobacteriaceae strains carried blaCTX-M gene, which is a common ESBL gene in clinics. The study demonstrates that tilapia found in the polluted waters can serve as reservoirs and an alternative route for human exposure to clinically important ARG-carrying bacteria. The consumption and handling of these fish may pose a potential health risk.

First Report of blaCTX-M-15 Extended Spectrum Beta-Lactamase (ESBL) Producing E. Coli Isolated from Cloacal Swabs of Birds in South Eastern Nigeria

Introduction: In this study, we investigated the presence of some beta-lactamases namely SHV, TEM and the most widely spread extended spectrum beta-lactamase (blaCTX-M-15) genes in E. coli isolated from four different bird species including ducks, pigeons, weaverbirds and bats in Ebonyi State, Nigeria. Methodology: Genes for ESBL production was determined based on PCR amplification of the genes encoding the enzymes including TEM, SHV and CTX-M-15 using specific primers. One hundred and fifty cloacal swabs each from ducks and pigeons and 100 each from weaverbirds and bats were respectively collected using sterile swab sticks. Antibiotic susceptibility test on the isolates was conducted using disc diffusion method while the phenotypic determination of ESBL was carried out using Double Disc Synergy Tests (DDST). Observations: Results from this study showed that E. coli was present in all the 4 bird species investigated. Of the 117 isolates screened for ESBL production, only 3(5.56 %) and 9(16.67 %), respectively were positive from ducks and pigeons while none was positive from bats and weaverbirds. Results of the molecular studies showed that the ESBL producing E. coli from pigeons were negative for SHV genes, positive for TEM and CTX-M-15 while those from ducks did not harbour any of the beta-lactamase and ESBL genes investigated.  Conclusion: The detection of similar types of beta-lactamase and ESBL genes (TEM and CTX-M-15) in pigeon samples indicates the possible involvement of some bird species in the spread of multidrug resistant genes across human population. This is the first report of CTX-M-15 ESBL in bird species from Southeast Nigeria.

Study on integron drug resistance gene of ESBLs-prodcing Klebsiella pneumonia infection in ICU elderly patients / 国际检验医学杂志

Objective To understand the gene distribution and drug resistance rate of integron gene of extended spectrumβ‐lac‐tamases(ESBLs) producing Klebsiella pneumonia infection in ICU elderly patients in order to provide the basis for rational use of antimicrobial agents .Methods The BioMerieux VITEK‐2 Automated Microbes Identification System was adopted to conduct the bacteria identification and drug susceptibility test on various clinical specimens of ICU elderly patients in our hospital from January 2013 to December 2015 .The integron gene in 167 strains of ESBLs‐producing Klebsiella pneumoniae was analyzed by PCR ,and the gene was identified by sequencing .Results Among 386 strains of Klebsiella pneumoniae ,the detection rate of ESBLs‐producing strains was 43 .26% ;the positive rate of integron was 50 .89% ,the detected integron was class Ⅰ integron;aadA2 ,aadA1 ,aada16 , dfra27 and arr‐3 genes were amplified from integron variable region;the drug resistance rate of ESBLs‐producing integron gene pos‐itive strains was significantly higher than that of integron gene negative strains .Conclusion the ICU elderly patients with ESBLs‐producing Klebsiella pneumoniae infection is closely related to the integron gene and integron plays an important role in bacterial drug resistance .

Distribution and homology of foodborne-associated extended-spectrumβ-lactamases-producing Escherichia coli / 中国感染控制杂志

Objective To study the distribution and homology of foodborne-associated extended-spectrumβ-lacta-mases (ESBLs)-producing Escherichiacoli (E. coli).Methods ESBLs-producing E. coli were isolated from differ-ent food specimens in Shaoguan from 2014 to 2015,strains were typed with pulsed-field gel electrophoresis (PFGE) and BioNumerics software.Results 1 1 strains of diarrhea-causing E. coli and 29 strains of ESBLs-producing E. co-li were isolated from 347 different sources of food specimens. PFGE analysis showed that 29 strains could be divided into 21 cluster groups,group A was predominant pattern,which included 7 strains(J2,J3,J4,J7,J9,B4,S3), group B included 2 strains (J6,J8),the other strains were sporadic clones. Similarity coefficient (SC)of 3 strains (J2,J7,J9)from health practitioners was 100% ,SC of strains from drinking water and patients with diarrhea (B4) was 97. 1% ,SC of S3 strain and 4 strains (J2,J3,J7,J9 )from health practitioners were all>90. 0% . Conclusion Foodborne-associated ESBLs-producing E. coli are widely distributed in food,water,animal,and pop-ulations,and can be transmitted through food chain,surveillance should enhanced to avoid further spread.

Analysis on the Antimicrobial Susceptibilities and the Prevalence of ESBLs Encoding Genes of Escherichia Coli Isolates Collected from Blood / 现代检验医学杂志

Objective To analyze the susceptibilities of Escherichia coli isolates collected from blood and the prevalence of ESBLs encoding genes.Methods A total of 121 Escherichia coli isolates collected from blood during 2012 were analyzed for antimicrobial susceptibilities by software of WHONET 5.6,the production of ESBLs was confirmed by confirmatory pheno-typic testing,PCR and DNA sequence were further implemented to analyze the ESBLs-encoding genes.Results 121 E.coli isolates displayed high resistance towards broad spectrum penicillin and 2nd or 3rd generation cephalosporins,levofloxacin and cotrimoxazole,with the resistance rates being more than 40%,susceptibilities to imipenem,piperacillin/tazobactam,ami-kacin were observed,with the resistance rates to be less than 12%,86(88.7%)out of 121 isolates were found to produce ESBLs.Among them,59.5% (72),38.8% (47)and 4.1% (5)were confirmed to carry blaCTX-M,blaTEM and blaSHV genes.Additionally,2(1.7%)isolates carried all the genes detected,30(24.8%)isolates carried both of blaCTX and bla-TEM,1(0.8%)isolate carried both of blaSHV andblaTEM.Conclusion Most of the E.coli isolates from the blood culture in Nanjing Gulou Hospital produce ESBLs,and displayed resistance towards most of the penicillins,cephalosporins and sin-gle amide antimicrobial agents should be chosen according to susceptibility results.

Clinical analysis of 408 children with positive blood culture of Escherichia coli / 临床儿科杂志

Objective To investigate the clinical manifestations and the antibiotics resistance patterns in children with positive blood culture of Escherichia coli. Methods The clinical data of children with positive blood culture of Escherichia coli were retrospectively analyzed from Jan.2007 to Dec.2014. Results In a total of 154774 children who had blood culture in the study period, 8446 children were positive, among whom 408 (4.83%) children were isolated Escherichia coli. The children with the positive blood culture of Escherichia coli mainly were under one year old (51.72%), of which 36.77%was neonates. There were 275 children had underlying diseases, and the most common disease was Leukemia. 199 (48.77%) Escherichia coli strains were producing extended spectrumβ-lactamase (ESBLs) and 85.23%were resistant to ampicillin. All strains were susceptible to meropenem. Conclusions Septicemia caused by Escherichia coli is usually occurred in children with leukemia or in neonates. Since blood infections of Escherichia coil had high rate of ESBLs, the use of carbapenem antibiotics should be cautious.

Difference in antimicrobial susceptibility of common clinical pathogens to different ratios of cefoperazone/sulbactam antimicrobial disks / 中国感染控制杂志

Objective To understand the antimicrobial resistance of common clinical pathogens to antimicrobial disks containing different ratios of cefoperazone/sulbactam,so as to provide basis for rational application of cefoper-azone/sulbactam in clinic.Methods 1 141 pathogens isolated from clinical specimens in a hospital in the first half year of 2014 were collected,disk diffusion method was adopted to detect antimicrobial activity of two kinds of cef-operazone/sulbactam disks (70/35 μg and 75/75 μg).Results Of 1 141 pathogenic strains,675 (59.16%)were En-terobacteriaceae,447 (39.18%)were non-fermentative bacteria,and 19 (1 .66%)were other gram-negative bacilli. Resistance rates of pathogens to 70/35μg and 75/75 μg cefoperazone/sulbactam antimicrobial disks were as follows:extended-spectrumβ-lactamases(ESBLs)-producing Escherichia coli (n=221)were 7.69% and 2.26% respective-ly,ESBLs-producing Klebsiella pneumoniae (n=92)10.87% and 3.26% respectively,imipenem-resistant Acineto-bacter baumannii (IRAB,n=295)54.92% and 11 .19%respectively;there were significant differences in antimicrobial activity between two ratios of antimicrobial disks(P 0.05).Conclusion Antimicrobial activity of two different ratios of cefoperazone/sulbactam antimicrobial disks to ESBLs-producing Enterobacteriaceae and IRAB is different,attention should be paid to ratios of cefoperazone/sulbactam during the treatment ,so as to achieve the desired therapeutic effect.