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Objective:To investigate the pathogenic bacteria profiles in preoperative urine bacterial cultures of patients with infected kidney stones and use antibacterial drugs to prevent recurrence.Methods:The data of 79 cases with infected kidney stones admitted to the Second Affiliated Hospital of Zhengzhou University from January 2017 to July 2021 were retrospectively analyzed, among whom 29 (36.7%) were male and 50 (63.3%) were female. The age ranged from 17-75 years, with a median age of 49.0 (40, 55) years. Fifteen cases (19.0%) combined hypertension, 13 cases (16.5%) combined diabetes mellitus, and 3 cases (3.8%) combined with cardiovascular disease. Fifty-one cases (64.6%) were diagnosed with cast infectious stones. All patients underwent surgical lithotripsy, and postoperative review of the urological computerized tomography (CT) revealed no residual stones defined as complete lithotripsy, and postoperative oral medication was continued to control infection and prevent stone recurrence. According to post-hospitalization compliance, patients were divided into high and low compliance groups. The high compliance group consisted of patients who returned to the hospital regularly for routine urinalysis and urine bacterial culture after discharge, followed the doctor's prescription for standardized antibacterial drug therapy, and complied with urease inhibitor therapy for ≥6 months. The low compliance group included patients who did not take sensitive antimicrobial drugs regularly and/or were unable to adhere to the medication even after the reduction of vinblastine due to adverse events such as tremor, palpitations, headache, anemia, or gastrointestinal discomfort. The recurrence of stones at 3, 6 and 12 months of follow-up was compared between the two groups.Results:Of the 79 cases in this group, 56(70.9%) were completely clear of stone after surgery. Thirty-three cases (41.8%) presented positive in preoperative urine bacterial culture, and the most common causative organism was Aspergillus oddus in 17 cases (21.5%), followed by Escherichia coli in 8 cases (10.1%) and Klebsiella pneumoniae in 3 cases (3.8%). Among the 17 positive cases of A. oddis, six were positive for ultra broad spectrum β-lactamases (ESBLs), 6/6 were resistant to ampicillin, cefazolin, and cotrimoxazole, 1/6 were resistant to amikacin, cefoxitin, and ticarcillin/stick acid, and none were resistant to imipenem, polymyxin, or aminotrans (0/6 cases). Of the cases, 11 were negative for ESBLs. Ten out of eleven cases were resistant to ampicillin. Furthermore, 8/11 cases were resistant to cefazolin, levofloxacin, ciprofloxacin, and cotrimoxazole and 1/11 were resistant to cefoxitin, cefaclor, furantoin, amikacin, and minocycline, and 0/11 were resistant to imipenem, ticarcillin/stick acid, aminotrans. ESBLs positive strains were resistant to 78.6% of the tested drugs (cefaclor, cefazolin, ceftazidime, furantoin, norfloxacin, levofloxacin, ciprofloxacin, cefoxitin, amoxicillin/rod acid, ticarcillin/rod acid, ampicillin, ceftriaxone, cefotaxime, cefuroxime, cefepime, gentamicin, cotrimoxazole, tobramycin, amikacin, tetracycline, chloramphenicol, and minocycline) at a lower rate of resistance than ESBLs positive strains. Of the eight positive cases of E. coli, seven were ESBLs positive, 7/7 were resistant to ampicillin, cefazolin, cefotaxime, cefuroxime, and cefepime, 1/7 were resistant to cefoxitin and minocycline, and 0/7 were resistant to imipenem, furantoin, or amikacin. One case was ESBLs negative and was resistant to all antimicrobial drugs except for ampicillin. Stone recurrence rates at 3, 6, and 12 months after discharge were 9.1%(4/44) and 31.4%(11/35), 13.6%(6/44), respectively, in the high compliance group, and 60.0%(21/35), 36.4%(16/44), and 71.4% (25/35), respectively, in the low compliance group. All differences were statistically significant.Conclusion:The most common pathogenic bacteria isolated from urine bacterial cultures of patients with infectious stones were A. chimaera, E. coli, and K. pneumoniae. The resistance rate of ESBLs-positive strains to antimicrobial drugs was significantly higher than that of ESBL-negative strains, and the resistance rate of antimicrobial drugs such as β-lactamase inhibitors, cefoxitin, amikacin, and imipenem was low. Combination therapy with standardized sensitive antimicrobial drugs and urease inhibitors significantly reduced the recurrence rate of stones among patients.
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Objective:To analyze the characteristics of drug resistance genes in a Klebsiella pneumoniae strain coproducing carbapenemases KPC-2 and NDM-5. Methods:Klebsiella pneumoniae KPN-hnqyy was separated from the stool specimen of a patient in the Hematology Department of Affiliated Cancer Hospital of Zhengzhou University. The strain was identified with a BD Phenix-M50 automated microbiology system and the minimum inhibitory concentration against the strain was measured as well. The genotypes of the carbapenemases were tested by enzyme immunochromatographic assay and PCR method. The transferability of related plasmids was analyzed by conjugation test. Whole-genome sequencing of the strain was conducted using PacBio and Illumina platforms. The MLST type, resistance gene and plasmid type of the strain were retrieved in BacWGSTdb. The genome and open reading frame sequence of the strain were compared using Easyfig_2.2.3. Visual cycle graphs were generated using BRIG v0.95. Results:Klebsiella pneumoniae KPN-hnqyy was resistant to carbapenem antibiotics. It belonged to ST11 and carried two carbapenemase genes of blaKPC-2 and blaNDM-5. The conjugant only harbored the blaKPC-2 gene. Whole-genome sequencing revealed that the strain contained one chromosome and three plasmids. Its chromosome genome shared more than 99.9% similarity with that of Klebsiella pneumonia KP69 and KP19-2029. Moreover, a similar IncR and IncFⅠ resistance gene fusion region was contained in different types of plasmids carried by them: the blaKPC-2 gene was located in a structure—which evolved from the Tn3-△Tn4401-Tn1721/Tn1722 sequence—inside this fusion region with its ends inserted into the transposase IS26 gene; the blaNDM-5 gene was located on a transposon containing the special plasmids of the insertion fragment in phages, with its ends inserted into the transposase IS26 gene too. Conclusions:The IncR and IncFⅡ resistance gene fusion region of blaKPC-2 carried by Klebsiella pneumoniae ST11 might be widely coexistent with the chromosomal genome. The blaNDM-5 gene carried by special plasmids might be accidentally obtained through gene recombination mediated by transposable element IS26. The wide transmission of Klebsiella pneumoniae ST11 carrying the blaKPC-2 gene in China and its ability to obtain other carbapenemase genes through transposable element IS26 were well worth attention.
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Various boron-containing drugs have been approved for clinical use over the past two decades, and more are currently in clinical trials. The increasing interest in boron-containing compounds is due to their unique binding properties to biological targets; for example, boron substitution can be used to modulate biological activity, pharmacokinetic properties, and drug resistance. In this perspective, we aim to comprehensively review the current status of boron compounds in drug discovery, focusing especially on progress from 2015 to December 2020. We classify these compounds into groups showing anticancer, antibacterial, antiviral, antiparasitic and other activities, and discuss the biological targets associated with each activity, as well as potential future developments.
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Background: Antimicrobial resistance poses a major threat in the treatment of respiratory disease especially in developing countries like Bangladesh. Multidrug-resistant (MDR) bacteria along with extremely drug resistant (XDR) bacteria have emerged as major clinical and therapeutic dilemma in the treatment of tracheal infections here. Thus, the aim of this study is to assess multidrug resistance among clinical strains isolated from tracheal aspirates of patients in Dhaka, Bangladesh.Methods: Total 200 clinical isolates from tracheal aspirates were identified and their antibiotic susceptibility profiles were evaluated by using the VITEK 2 system following the Clinical and Laboratory Standards Institute guidelines. Patient information on diagnosis, sex, age was obtained from hospital data.Results: Of 200 clinical isolates obtained, Pseudomonas aeruginosa was the most frequent pathogens (30.5%) followed by Acinetobacter baumannii (29%), Klebsiella pneumoniae (22.5%), Streptococcus pneumoniae (7.5%), Escherichia coli (5%), Staphylococcus aureus (2%), Proteus spp (1.5%), Enterobacter spp (1%), Citrobacter spp (0.5%), Providencia spp (0.5%). Of 20 different antibiotics tested, highest number of isolates (86%) showed resistance to third generation cephalosporin cefixime, however least number of isolates showed resistance to polymixin antibiotics- colistin (12.5%) and polymixin B (6%). Tracheal infection was found to be more prevalent in males rather than in females although this difference was not statistically significant. The prevalence of infections was highest among the patients of age-group (old adults) ≥60 years (61.5%). Of 200 clinical isolates, 43 (21.5%) were XDR and 125 (62.5%) were MDR bacteria. Of 200 clinical isolates, the synthesis of extended spectrum β-lactamases (ESBL) and carbepenemase were detected in 59 (29.5%) and 98 (49%) strains respectively.Conclusions: Tracheal infections caused by β-lactamase producing MDR and XDR pathogens among patients are high in Dhaka, Bangladesh. Therefore, there is an urgent need for constant surveillance and interventions in Bangladesh in order to prevent further spreading of those resistant organisms.
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Objective To predict monthly incidents of extended spectrum β-Lactamases (ESBLs)-producing Escherichia coli in Zhejiang Hospital by establishing multiple seasonal autoregressive integrated moving average (ARIMA) model, so as to provide scientific evidence for reducing the incidents of nosocomial infection of ESBLs producing Escherichia coli. Methods Multiple seasonal ARIMA model was established by monthly records of ESBLs producing Escherichia coli from 2010 to 2016 in Zhejiang hospital. Monthly incidents of ESBLs producing Escherichia coli from 2017 to February 2018 were used to verify the predicted result. The predictions were evaluated by models of mean absolute percent error (MAPE) and bayesian information criterion (BIC) . Results The optional model for the monthly incidence from 2010 to 2016 was ARIMA (0, 1, 1) (0, 1, 1)12. The MAPE was 14.76, BIC was 2.01, and the Ljung-Box statistics value Q was 16.79 (P=0.40) . These parameters suggested a good model fitting. The average relative error between the predictive value and the actual value of the monthly incidents ESBLs producing Escherichia coli from 2017 to February 2018 was 14.08%.The actual values were within the 95% confidence interval. Conclusion The multiple seasonal ARIMA model of ARIMA (0, 1, 1) (0, 1, 1 )12 fits and can be used for short-term prediction and dynamic analysis of the incidents of ESBLs producing Escherichia coli in Zhejiang Hospital.
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Objectives To explore the distribution of CTX-M drug resistance genotypes in Escherichia coli isolated from urethra in children and the influence of pH changes on its drug resistance. Methods A total of 113 strains of Escherichia coli isolated from clean midstream urine in children with urinary tract infection were cultured from October 2013 to May 2014. The drug sensitivity of ESBL-producing Escherichia coli was detected and counted. The distribution of CTX-M drug resistance genotypes were analyzed by PCR and gene sequencing. Different pH environment was established in vitro to evaluate the effect of pH on drug resistance of CTX-M resistant Escherichia coli. Results In 113 Escherichia coli strains, there were 68 ESBL-producing strains (60.18％), in which rate of drug resistance to meropenem and imipenem were 1.47％ and 2.94％ respectively. There were 41 strains carried CTX-M drug resistance genotype, which mainly were type CTX-M-14 and type CTX-M-15, 18 strains each. Compared with neutral environment of the pH value at 6 or 6.5, the rate of Escherichia coli resistant to cefuroxime, cefotaxime, ceftazidime and ceftriaxone had no difference (P>0.05), while the resistance to cefepime was significantly increased when pH was 6.0 (P<0.01). With the pH value at 8 or 8.5, the rate of Escherichia coli resistance to ceftazidime and cefepime was significantly decreased, and with the pH value at 8.5 the rate of Escherichia coli resistance to cefotaxime also significantly decreased (P<0.01). Conclusions The rate of ESBL-producing Escherichia coli resistance to carbapenem antibiotic is low. The rate of Escherichia coli carrying CTX-M drug resistance genotype is high with CTX-M-14 and CTX-M-15 being the most prevalent genotypes. Properly alkalization of urine may contribute to the treatment of CTX-M resistant Escherichia coli in children with urinary tract infection.
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OBJECTIVES: Antimicrobial resistant extended-spectrum-β-lactamase-producing Enterobacteriaceae (ESBL-PE) have been shown to be present in healthy communities. This study examined healthy children from the rural Andean village of Llano del Hato, Mérida, Venezuela, who have had little or no antibiotic exposure to determine the prevalence of fecal carriage of ESBL-producing Escherichia coli (ESBL-EC). METHODS: A total of 78 fecal samples were collected in healthy children aged from 1 to 5 years. ESBL-EC were selected in MacConkey agar plates with cefotaxime and further confirmed by the VITEK 2 system. ESBL were phenotypically detected and presence of bla genes and their variants were confirmed by molecular assays. Determination of phylogenetic groups was performed by PCR amplification. Risk factors associated with fecal carriage of ESBL-EC-positive isolates were analyzed using standard statistical methods. RESULTS: Of the 78 children studied, 27 (34.6%) carried ESBL-EC. All strains harbored the bla(CTX-M-15) allele. Of these, 8 were co-producers of bla(TEM-1), bla(TEM-5), bla(SHV-5) or bla(SHV-12). Co-resistance to aminoglycosides and/or fluoroquinolones was observed in 9 strains. 51.9% of ESBL-EC isolates were classified within phylogroup A. A significant, positive correlation was found between age (≥2.5 – ≤5 years), food consumption patterns and ESBL-EC fecal carriage. CONCLUSION: This is the first study describing the high prevalence of fecal carriage of ESBL-EC expressing CTX-M-15- among very young, healthy children from a rural Andean village in Venezuela with scarce antibiotic exposure, underlining the importance of this population as a reservoir.
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Child , Humans , Agar , Alleles , Aminoglycosides , Cefotaxime , Enterobacteriaceae , Escherichia coli , Escherichia , Fluoroquinolones , Polymerase Chain Reaction , Prevalence , Risk Factors , VenezuelaABSTRACT
Objective To investigate the antibiotic resistance and resistance genes of carbapenem-resistant Enterobacteriaceaes (CRE) isolated from 5 hospitals in Northeast China.Methods This study collected 85 CRE isolates during January 2013 to June 2015 from five hospitals in Northeast China.Drug sensitivities of 14 antimicrobial agents were determined by the broth microdilution method.The phenotypes of carbapenemases were screened by modified Hodge test and EDTA test respectively.The genotypes of carbapenemases and other extended spectrum β-lactamases (ESBL) were detected by PCR gene amplification and DNA sequencing method.Using the PCR result as gold standard, the performances of other two carbapenemase detection methods were evaluated.Results Among the 85 CRE strains collected in this study, Klebsiella pneumoniae was the most frequently isolated species (61/85,71.8%).The results of antimicrobial agent sensitivity showed that the 85 CRE strains had resistance rate of cephalosporin and β-lactams/enzyme inhibitor (piperacillin-tazobactam) over 80.0%.The resistance rate of carbapenem was high, with ertapenem 100.0% (85/85), meropenem 65.9% (56/85), imipenem 71.8% (61/85).There were 36 isolates resistant to both meropenem and imipenem.For fluoroquinolones, the resistance rates of levofloxacin and ciprofloxacin were 72.9% (62/85) and 65.9% (56/85), respectively.The resistance rate to fosfomycin and amikacin were 65.0% (55/85) and 54.1% (46/85), respectively.The resistance rate of colistin (21.2%, 18/85) and tigecycline (20.5%, 17/85) were low.Forty-nine strains were modified Hodge test positive and 12 strains were EDTA test positive.By PCR gene amplification and DNA sequencing method, 64 strains carried carbapenemase-encoding genes, of which KPC-2 was the main type (53/85, 62.4%), followed by IMP-4 (10/85, 11.8%), NDM-5 (7/85, 8.2%) and NDM-6 (1/85, 1.2%).At the same time, 85 CRE isolates had the ESBL gene detection and 47 isolates were CTX-M type ESBLs (47/85, 55.3%), with no TEM or SHV type.Conclusions Klebsiella pneumoniae is the majority of CRE strains from 5 large hospitals in Northeastern China.The CRE strains are resistant to most of antimicrobials.Most carbapenemases-producing isolates have the KPC-2 type.Nearly half of the carbapenemase-producing strains also carry ESBL genes, which makes the resistance mechanisms more complicated.
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BACKGROUND: Carbapenem-resistant Klebsiella pneumoniae (CRKP) is considered a serious global threat. However, little is known regarding the multidrug resistance (MDR) mechanisms of CRKP. This study investigated the phenotypes and MDR mechanisms of CRKP and identified their clonal characteristics. METHODS: PCR and sequencing were utilized to identify antibiotic resistance determinants. Integron gene cassette arrays were determined by restriction fragment length polymorphism (RFLP) analysis. Multi-locus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) were used for epidemiological analysis. Plasmids were typed by using a PCR-based replicon typing and analyzed by conjugation and transformation assays. RESULTS: Seventy-eight strains were identified as resistant to at least one carbapenem; these CRKP strains had a high prevalence rate (38.5%, 30/78) of carbapenemase producers. Additionally, most isolates harbored MDR genes, including Extended spectrum β-lactamases (ESBLs), AmpC, and quinolone and aminoglycoside resistance genes. Loss of porin genes was observed, and Class 1 integron was detected in 66.7% of the investigated isolates. PFGE and MLST results excluded the occurrence of clonal dissemination among these isolates. CONCLUSIONS: A high prevalence of NDM-1 genes encoding carbapenem resistance determinants was demonstrated among the K. pneumoniae isolates. Importantly, this is the first report of bla(NDM-1) carriage in a K. pneumoniae ST1383 clone in China and of a MDR CRKP isolate co-harboring bla(NDM-1), bla(KPC-2), bla(CTX-M), bla(SHV), acc(6′)-Ib, rmtB, qnrB, and acc(6′)-Ib-cr.
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China , Clone Cells , Drug Resistance, Bacterial , Drug Resistance, Microbial , Drug Resistance, Multiple , Electrophoresis, Gel, Pulsed-Field , Genes, MDR , Integrons , Klebsiella pneumoniae , Klebsiella , Molecular Epidemiology , Phenotype , Plasmids , Pneumonia , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , Prevalence , RepliconABSTRACT
Background: Surveillance of antimicrobial resistance (AMR) is of great importance. Pseudomonas aeruginosa and Acinetobacter baumannii are important pathogens and emergence of resistance in these have increased the morbidity and mortality rates. This surveillance study was initiated by the Government of India ‑ Indian Council of Medical Research. The aim of this study is to determine the antimicrobial susceptibility profile and to characterise the enzyme mediated antimicrobial resistance such as extended spectrum beta‑lactamases (ESBLs) and carbapenemases among multidrug‑resistant (MDR) P. aeruginosa and A. baumannii. Materials and Methods: A multi‑centric study was conducted from January 2014 to December 2015 with a total number of 240 MDR P. aeruginosa and 312 MDR A. baumannii isolated from blood, cerebrospinal fluid, respiratory, pus, urine and intra‑abdominal infections. Kirby–Bauer disc diffusion was done to determine the antimicrobial susceptibility profile. Further, MDR isolates were characterised by multiplex polymerase chain reaction to determine the resistance genes for ESBLs and carbapenemases. Results: Among the ESBLs, blaVEB (23%), blaTEM (5%) and blaSHV (0.4%) in P. aeruginosa and blaPER (54%), blaTEM (16%) and blaSHV (1%) in A. baumannii were the most prevalent. Likewise, blaVIM (37%), blaNDM (14%), blaGES (8%) and blaIMP (2%) in P. aeruginosa and blaOXA‑23like (98%), blaOXA‑58like (2%), blaNDM (22%) and blaVIM (3%) in A. baumannii were found to be the most prevalent carbapenemases. blaOXA‑51like gene, intrinsic to A. baumannii was present in all the isolates tested. Conclusion: The data shown highlight the wide difference in the molecular mechanisms of AMR profile between P. aeruginosa and A. baumannii. In P. aeruginosa, plasmid‑mediated mechanisms are much lesser than the chromosomal mediated mechanisms. In A. baumannii, class D oxacillinases are more common than other mechanisms. Continuous surveillance to monitor the trends in AMR among MDR pathogens is important for implementation of infection control and to guide appropriate empirical antimicrobial therapy.
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Objective To investigate the incidences, risk factors, genotypes and epidemiology of community-acquired blood stream infection caused by extended spectrum β-lactamases (ESBLs)-producing Escherichia coli and Klebsiella pneumonia strains and to analyze the sensitivity of those ESBLs producing strains to commonly used antibiotics. Methods Forty-two patients who were diagnosed with community-ac-quired blood stream infection caused by Escherichia coli or Klebsiella pneumonia strains in Sichuan Provincial People′s Hospital were recruited in this study. Disc diffusion method was used for the phenotypic confirmato-ry test of ESBLs. Agar dilution method was performed to measure the antimicrobial susceptibility of the ESBLs-producing strains to 13 clinically commonly used antibiotics. Genotypes of the ESBLs-producing strains were identified by polymerase chain reaction (PCR). Multilocus sequence typing (MLST) was used to analyze the epidemiology of ESBLs-producing strains. Logistic regression analysis was performed to analyze the risk factors for community-acquired blood stream infection. Results The ESBLs-producing Escherichia coli strains accounted for 56. 3% (18 / 32) and the ESBLs-producing Klebsiella pneumoniae strains accounted for 20% (2 / 10). All of the 20 ESBLs-producing strains were sensitive to imipenem, meropenem, ertapen-em, nitrofurantoin and moxalactam. The ESBLs-producing strains sensitive to amikacin, piperacillin-tazobactam and fosfomycin accounted for 95% , 90% and 85% , respectively. Drug resistance rates of the 20 strains to cefotaxime, levofloxacin, ciprofloxacin and cefepime were relatively high accounting for 100% , 80% , 80% and 75% , respectively. Among the 20 ESBLs-producing strains, 7 strains only carried the CTM gene, while the other 13 strains were all positive for two genotypes of ESBLs, mainly identified as TEM+CTM-M-14 and TEM+CTM-15 genotypes. The 18 Escherichia coli strains were classified into 10 ST types, most of which were ST131 type, followed by ST10 and ST38 types. This study indicated that malignant tumor might be a possible risk factor. Conclusion The prevalence of community-acquired blood stream infection caused by ESBLs-producing Escherichia coli strains was becoming increasingly serious. Malignant tumor might be the risk factor associated with the producing of ESBLs in Escherichia coli and Klebsiella pneumonia strains. TEM+CTX-M-14 was the predominant genotype of ESBLs-producing strains and the prevalent clone was ST131 type. Carbapenems and enzyme inhibitor compounds were ideal drugs for the treatment of commu-nity-acquired blood stream infection caused by ESBLs-producing Escherichia coli and Klebsiella pneumonia strains. This study was limited by the small sample size. Therefore, it is necessary to conduct further resear-ches based on a large number of samples.
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Context: Carbapenemase production is an important mechanism responsible for carbapenem resistance. Aims: Phenotypic detection and differentiation of types of carbapenemase in carbapenem resistant Enterobacteriaceae is important for proper infection control and appropriate patient management. Settings and Design: We planned a study to determine the occurrence of Class A Klebsiella pneumoniae carbapenemase (KPC type) and Class B Metallo-β-lactamase (MBL type) carbapenemase in hospital and community. Materials and Methods: Clinical isolates of Escherichia coli and Klebsiella species and simultaneously evaluate different phenotypic methods for detection of carbapenemases. Results: It was observed that 20.72% clinical isolates of E. coli and Klebsiella spp. were resistant to carbapenem on screening of which, 14.64% were E. coli and 29.69% were Klebsiella spp. Using phenotypic confirmatory tests the occurrence of carbapenemase production was found to be 87.01% in E. coli and 91.51% in Klebsiella spp. using both modified Hodge test (MHT) and combined disk test (CDT) using imipenem-ethylenediaminetetraacetic acid. Conclusions: Both MBL and KPC type carbapenemases were seen among clinical isolates of E. coli and Klebsiella spp. CDT is simple, rapid and technically less demanding procedure, which can be used in all clinical laboratories. Supplementing MHT with CDT is reliable phenotypic tests to identify the class A and class B carbapenemase producers.
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ObjectiveTo study the correlation with Genes Coding forESBLs and ClassⅠIntegron in ESBLs-producing Escherichia coli from children.MethodsPCR was used for gene typing detection of 100 strains of ESBLs-producingEsche-richia colistrains. While detection of class I integrase gene in the 100 strains ESBLs-producingEscherichia coli and 100 strains of non-ESBLs producingEscherichia coli were separately performed by PCR. It provides the solid base not only to reveal the relationship between class I integron and drug resistance, but also the relationship between class I integron and ESBLs-producing. ResultsThe most frequently genotyping from ESBLs-producingEscherichia coli in children isCTX-M (84%), followed by TEM-1(63%). The predominant distribution of genotype in ESBL- producing strains isTEM-1 +CTX-M (45%), followed by CTX-M (34%). Class I integrase gene detected in ESBLs- producing and non- ESBLs producing strain were 100 cases (100%) and 25 cases (25%) separately, the difference was statistically signiifcant (P<0.05); drug resistance in class I integron positive strains were signiifcantly higher than in class I integron negative strains, especially in Ciprolfoxacin, Levolfoxacin, and Amino-glycoside (86.4%, 88%, and 80%).ConclusionsThe distribution of Class I integron in ESBLs-producingEscherichia coli is signiifcantly higher than that in non-ESBLs-producing strains, It is rational that Class I integron highly correlate with strong drug resistance in ESBLs-producing strains.
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Context: Plasmid mediated AmpC (pAmpC) β-lactamase producing Escherichia coli are an emerging problem worldwide as they are now exhibiting resistance to multiple classes of antibiotics and are a major cause of therapeutic failure. Aims: The aim of this study was to characterize pAmpC β-lactamase producing extraintestinal E. coli, their phylogenetic distribution, resistance pattern, treatment options, and impact on patient’s clinical outcome. Settings and Design: This descriptive study was carried out in a multi-specialty tertiary care hospital. Materials and Methods: A total of 300 clinically signifi cant, non-repeat isolates were studied. AmpC disk test was used for phenotypic AmpC-β- lactamase detection. Molecular types of pAmpC were determined by a multiplex polymerase chain reaction (PCR). Phylogenetic analysis was performed by triplex PCR methods. Metallo-beta-lactamase (MBL) detection was done by E test. Antibiogram, treatment, and clinical outcome were collected in a structured proforma. Results: Although 95 isolates (32%) were phenotypically positive for AmpC, PCR detected CIT type of AmpC gene in only 37 isolates. Majority of strains were from phylogroup A (85%) and B1 (58%) which are considered as commensal groups. Co-production of ESBL’s was observed in 33 strains and 5 strains were found to be MBL producers. Most widely prescribed antibiotics were 3rd generation cephalosporins (30%), carbapenems (19%) and aminoglycosides (16%). Conclusions: Plasmid mediated AmpC producing isolates were found to exhibit a high degree of drug resistance, and they mainly belonged to commensal strains possibly due to misuse of antibiotics. Proper antibiotic policy is required to limit the spread of pAmpC producers or else it will lead to a therapeutic dead end in the near future.
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Extended-spectrum β-lactamases (ESBLs) and AmpC β-lactamases continue to be a major problem in healthcare settings. Due to the scarcity of information regarding the antibiotic susceptibility patterns particularly from urinary tract infections (UTIs) and wound infections, the current study was carried out to assist the clinicians to prescribe appropriate antibiotics against gram-negative clinical isolates. In the current study, urine (n = 620) and pus (n = 228) samples were collected from different sites (at various clinical departments) and subjected to direct microscopic examination, culture and antibiotic susceptibility testing (AST). In the AST testings, the isolates that exhibited reduced zone of inhibition to one or more of the antibiotics such as cefotaxime (≤27 mm), ceftriaxone (≤25 mm), ceftazidime (≤22 mm), cefpodoxime (≤17 mm) and aztreonam (≤27 mm) were considered as potential ESBL producers and the ESBL production was confirmed using phenotypic screening test (doubledisk synergy test) and phenotypic confirmatory test (combined-disk test). However, isolates showing resistance or decreased sensitivity to cefoxitin, cefotaxime, ceftriaxone, ceftazidime, cefpodoxime or aztreonam and sensitive to cefepime were considered as a screen positive AmpC producer and subjected to AmpC disk tests. The current study concluded that 72.41% and 21.76% of ESBL and AmpC producers were detected, respectively in our hospital. It was also observed that the double-disk synergy and combined-disk tests were equally effective for ESBL detection. Further, AmpC disk test is simple, easy to perform and interpret, requiring less expertise for the rapid detection of AmpC isolates.
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Background: Ventilator-associated pneumonia (VAP) is the most common infection diagnosed in intensive care units (ICUs). The causative organisms of VAP vary among different populations and are increasingly associated with resistance against various antimicrobial agents. Objective of current study was to determine the bacteriological etiology of VAP, antimicrobial susceptibility pattern of the isolates and detect the presence of extended-spectrum -lactamases (ESBL), metallo β-lactamases (MBL) and AmpC -lactamases in multidrug resistant isolates causing VAP in the medical ICU. Methods: A prospective study was carried out over a year to know the various etiological agents of VAP and their drug susceptibility patterns. ESBL, MBL and AmpC -lactamases were detected in various isolates by combination disk method, imipenem-EDTA combined disk method and AmpC disk method respectively. Results: The majority of bacterial isolates causing VAP were found to be gram negative bacilli. Acinetobacter spp accounted for 34.28% of VAP cases followed by Pseudomonas aeruginosa which was responsible for 25.71% cases. Other gram negative bacilli isolated were Klebsiella pneumoniae, Citrobacter freundii, Enterobacter spp, and Escherichia coli. Out of the total 70 isolates, 67 (95.7%) were multidrug resistant and not even a single isolate was sensitive to all the drugs tested. Conclusions: Most of the pathogens causing VAP in our institute were multidrug resistant and in many isolates this resistance was due to production of ESBL, MBL, and AmpC β-latamases. Polymixin-B and colistin were found to be highly effective against multidrug resistant Acinetobacter spp and P. aeruginosa.
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Objective: To study the prevalence of extended-spectrum β-lactamases (ESBLs) among 663 clinical isolates obtained from various parts of India and to study the occurrence of different variants of ESBLs among these isolates. Methods: Phenotypic characterization and susceptibility studies were performed according to the methods described in Clinical and Laboratory Standards Institute guidelines. The occurrence of ESBL variants was analyzed with PCR using the previously reported primers. Results: Among the six hundred sixty three isolates, the identified isolates were Acinetobacter baumannii (72), Escherichia coli (218), Klebsiella pneumoniae (30), Klebsiella oxytoca (63), Pseudomonas aeruginosa (264) and Staphylococcus aureus (16). PCR results revealed that approximately 89.0% of Pseudomonas aeruginosa isolates were positive for ESBL followed by Escherichia coli (85.3%), Klebsiella pneumoniae (76.6%), Klebsiella oxytoca (73.0%), Acinetobacter baumannii (72.2%) and Staphylococcus aureus (31.2%). The overall prevalence of ESBL was 82.5%. The presence of TEM type ESBLs were the predominant (in 186 isolates), followed by SHV (138), OXA (92), CTX-M (65), AmpC (33), KPC (28) and blaZ (5). Of the drugs involved in the study, CSE1034 was found to be the most efficacious against all of ESBL positive clinical isolates showing susceptibility approximately 95.7% with minimal inhibitory concentration values between 0.125 and 8.000 μg/mL for all strains tested. The susceptibilities of penems (meropenem and imipenem and cilastatin) ranged between 83% and 93% for all the isolates. The susceptibilities of other drugs like piperacillin and tazobactam, amoxicillin and clavulanic acid, cefoperazone and sulbactam were <45% for all the isolates. Conclusions: Results of the present study indicated that majority of the isolates was susceptible to CSE1034 and it could be a potent antibacterial agent for the treatment of severe bacterial infections caused by such organisms.
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OBJECTIVE@#To study the prevalence of extended-spectrum β-lactamases (ESBLs) among 663 clinical isolates obtained from various parts of India and to study the occurrence of different variants of ESBLs among these isolates.@*METHODS@#Phenotypic characterization and susceptibility studies were performed according to the methods described in Clinical and Laboratory Standards Institute guidelines. The occurrence of ESBL variants was analyzed with PCR using the previously reported primers.@*RESULTS@#Among the six hundred sixty three isolates, the identified isolates were Acinetobacter baumannii (72), Escherichia coli (218), Klebsiella pneumoniae (30), Klebsiella oxytoca (63), Pseudomonas aeruginosa (264) and Staphylococcus aureus (16). PCR results revealed that approximately 89.0% of Pseudomonas aeruginosa isolates were positive for ESBL followed by Escherichia coli (85.3%), Klebsiella pneumoniae (76.6%), Klebsiella oxytoca (73.0%), Acinetobacter baumannii (72.2%) and Staphylococcus aureus (31.2%). The overall prevalence of ESBL was 82.5%. The presence of TEM type ESBLs were the predominant (in 186 isolates), followed by SHV (138), OXA (92), CTX-M (65), AmpC (33), KPC (28) and blaZ (5). Of the drugs involved in the study, CSE1034 was found to be the most efficacious against all of ESBL positive clinical isolates showing susceptibility approximately 95.7% with minimal inhibitory concentration values between 0.125 and 8.000 μg/mL for all strains tested. The susceptibilities of penems (meropenem and imipenem and cilastatin) ranged between 83% and 93% for all the isolates. The susceptibilities of other drugs like piperacillin and tazobactam, amoxicillin and clavulanic acid, cefoperazone and sulbactam were <45% for all the isolates.@*CONCLUSIONS@#Results of the present study indicated that majority of the isolates was susceptible to CSE1034 and it could be a potent antibacterial agent for the treatment of severe bacterial infections caused by such organisms.
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Objective To investigate the genotypes of extended spectrum β-lactamases (ESBLs) and their carrying modes in Escherichia coli (E.coli) isolates,and to analyze the mechanism of protein phosphorylation and ESBLs gene expression induced by β-lactam antibiotics or inhibited by histidine kinase inhibitors.Methods The predominant genotypes of ESBLs (KPC,TEM,SHV and CTX-M) and their carrying modes were identified by PCR and sequencing analysis.E-test and micro-tube dilution method were applied to measure minimal inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs).Immobilized metal ion affinity chromatography,bacterial protein phosphorylation detection kit and real-time fluorescent quantitation RT-PCR were performed to analyze the enhancing effects of 1/4 MIC penicillin or cefotaxime or the inhibitory effects of histidine kinase inhibitors (closantel,bromized or iodized methylimidazol) on protein phosphorylation and the expression of ESBLs at mRNA level in E.coli isolates.Results In 183 β-lactam antibiotics-resistant E.coli isolates,TEM and CTX-M genes (83.1％ and 77.1％) were highly expressed than other two ESBLs genes with a prevalent carrying mode of coexisting (65.0％) (P＜0.05).Penicillin or cefotaxime at 1/4 MIC induced the protein phosphorylation and promoted the expression of TEM,SHV and CTX-M at mRNA level (P＜0.05).Closantel (200 μmol),bromized methylimidazol (2 or 10 μmol) or iodized methylimidazol (20 or 50 μmol) could neither kill E.coli isolates nor inhibit their growth,but could inhibit the protein phosphorylation induced by above mentioned antibiotics and enhance the expression of ESBLs at mRNA level (P＜0.05).Moreover,the susceptibility of antibioticresistant E.coli strains to penicillin and cefotaxime were increased (P＜0.05).Conclusion TEM and CTX-M were the predominant genotypes of ESBLs carried by β-lactam antibiotics-resistant E.coli strains isolated from Zhejiang province,which were mostly found in a TEM plus CTX-M carrying mode.Sublethal dose of β-lactam antibiotics could up-regulate the expression of ESBLs genes in E.coli isolates via TCSS,but it could be inhibited by histidine kinase inhibitors.
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Objective To investigate the phenotypes and genotypes of extended -spectrum β-lacta-mases (ESBLs) and AmpC β-lactamases produced by cefoxitin-resistant Shigella strains isolated from Zhe-jiang province and the virulence of those strains .Methods Kirby-Bauer antibiotic testing was performed to screen cefoxitin-resistant strains from 356 Shigella isolates.The serotypes of the cefoxitin-resistant strains were detected .The phenotypes of ESBLs and AmpC β-lactamases from cefoxitin-resistant strains were detec-ted by ESBLs confirmatory test and AmpC-three-dimensional test ,respectively .The genotypes of ESBLs and AmpC β-lactamases were analyzed by PCR and sequence analysis .The virulence genes ( virA, ial, iapH, set1A, set1B and sen) in the cefoxitin-resistant strains were screened by PCR .Results Eight cefoxitin-re-sistant strains were identified from 356 Shigella isolates.Among them,six strains were identified as Shigella flexneri (S.fleaneri) strain (four F2a,one F2b and one F2c),and the rest were identified as Shigella sonnie (S.sonnei) strain.Among all eight cefoxitin-resistant strains,five strains showed positive results for ESBLs confirmatory test and two strains showed positive results for AmpC-three-dimensional test .Seven out of the eight strains harbor ESBLs genes (CTX-M-14,15,57 and/or OXA-30),two of which were positive for AmpC genes (DHA-1 and CMY-2).Five out of the eight cefoxitin-resistant strains carried all of the six tested viru-lence genes,while the other three strains possessed four virulence genes except for set1A and set1B.The two strains producing both ESBLs and AmpC β-lactamases were susceptible only to imipenem .Conclusion ESBLs positive isolates are prevalent strains of cefoxitin-resistant Shigella with potential high virulence .Some of them also produce AmpC β-lactamases ,and the DHA-1 type of AmpCβ-lactamase is identified for the first time in China .