ESBL, MBL and Ampc Lactamases Producing Superbugs – Havoc in the Intensive Care Units of Punjab India

Abstract

Background: An alarming rise in the rates of the antibiotic resistance has now become a serious and an increasingly common public health concern, with severe implications, especially in the intensive care units. A variety of ß-lactamases which include ESBLs, AmpC ß-lactamases and metallo-ß-lactamases, have emerged as the most worrisome mechanism of resistance among the gram negative bacteria, which pose a therapeutic challenge to the health care settings. Materials and Methods:The present study was aimed at knowing the prevalence of various ß-lactamases in the gram negative isolates which were obtained from ICU patients. A total 273 gram negative isolates from 913 clinical samples which were received over a period of one year were processed for their identification and their antimicrobial susceptibility pattern was determined. They were then screened for the ß-lactamase production.Results: Among the 273 isolates, the ß-lactamase production was observed in 193 strains. 96 (35.16%) strains were ESBL producers, followed by 30 (10.98%) metallo ß-lactamase (MBL) producers and 15(5.4%) AmpC producers. The major ESBL and AmpC producer was Escherichia coli, while Klebsiella pneumonia was the predominant MBL producer. The co production of the ESBL/MBL/ AmpC ß-lactamases was observed in 52 (19.04%) strains and it was more common in Escherichia coli. A multidrug resistance to the fluoroquinolones and the aminoglycosides was also observed in the ß-lactamase producing organisms. Conclusion:The high prevalence of the ß-lactamases in the ICU isolates emphasizes the need for a continuous surveillance in the ICUs to detect the resistant strains, strict guidelines for the antibiotic therapy and the implementation of infection control measures to reduce the increasing burden of antibiotic resistance. INTRODUCTIONThe incidence of nosocomial infections in the intensive care units (ICU) is showing a rising trend, mainly because of the severe clinical conditions which are associated with the impaired immunity, increasing the use of invasive diagnostic procedures, lapses in the sterilization and the disinfection techniques and the indiscriminate use of antibiotics. The β-lactam antibiotics are among the most frequently prescribed antibiotics in the ICUs world-wide, which are favoured because of their efficacy, broad spectra and low toxicity. The selective pressures which are generated by the indiscriminate use of the beta-lactam antibiotics have led to the selection of a variety of mutated forms of β-lactamases such as the ESBLs, AmpC β-lactamases and metallo-β-lactamases which have emerged as the most worrisome resistance mechanism which poses a therapeutic challenge to the health care settings [1]. These "newer β-lactamases" are capable of hydrolyzing a wide range of β-lactam antibiotics, notably the extended-spectrum penicillins and the third and fourth generation cephalosporins, which include the carbapenams [2]. The ESBL producing organisms also express the AmpC β-lactamases and they may be co-transferred with the plasmids...

Occurrence and antimicrobial susceptibility pattern of ESBL-producers among Gram-negative bacteria isolated from burn unit at the Al Shifa hospital in Gaza, Palestine : A short original article

“…No previous study has investigated the prevalence of extended spectrum beta-lactamases resistance in burn infection in Gaza strip, Palestine. The incidence of ESBL in gram-negative isolates was 37.5% (15 out of 40 isolates) which is similar to many studies, particularly from India, which showed a high prevalence of ESBL-producers that reached 39.8% and 35.16% in burn patients, respectively [3,21] and lower than reported from in Iraq ( 61.5%) iamong gram-negative bacteria [22]. In Iran, 21% of A. baumannii isolates from burn patients were found to be ESBL-producers [23].…”

EMPYEMA THORACIS: Bacteriological analysis of pleural fluid from the largest chest hospital in Delhi

“…The prevalence of MBL in the present study is in concordance with the published literature [10,32]. Amongst the imipenem resistant Pseudomonas isolates 25% were MBL producers while mechanisms other than MBL production operated in the remaining 75% imipenem resistant isolates.…”

“…ESBL and AmpC production was maximum in E.coli followed by Klebsiella spp as observed in various reports worldwide [29]. This increased number of AmpC producers is in agreement with other works from India which reported 17.3% AmpC producers in Kolkata [10] and 22.9% by Bandekar et al [10]. This rising ESBL production poses a daunting challenge in gram negative antibiotic resistance, indicative of an ominous trend of more and more isolates acquiring the resistance mechanisms.…”

“…The isolates which showed reduced susceptibility to cefoxitin were tested for confirming AmpC production using the modified three-dimensional test. An indentation or flattening of the zone of inhibition indicated the AmpC production [10].…”

Evaluation of a 12 Disc Test for Phenotypic Detection of β- lactamases Resistance in Gram Negative Bacilli

“…This has emerged as the most worrisome resistance mechanism posing a therapeutic challenge to the health care settings as they are capable of hydrolyzing a wide range of β-lactam antibiotics, notably the extended-spectrum penicillins, third and fourth generation cephalosporins, and the carbapenems (Oberoi L. et al, 2013) The confirmed ESβL-producing isolates should be reported as resistant to all penicillins, cephalosporins, and aztreonam to avoid therapy with antibiotics that may be clinically ineffective but bacteria producing these enzymes may not be recognized as they are falsely susceptible in routine tests as a result patients start receiving ineffective antibiotics which contributes to the spread of the pathogens with hidden resistance. Tests based on ceftazidime and cefotaxime tested alone and in combination with clavulanate are useful in ESBL detection but they may yield false positive results with Klebsiella pneumonia carbapenemase (KPCs) and hyper produced K1β-lactamaes (K1βL) and false negative results with isolates that coproduce a high level of AmpCβL.…”