Antimicrobial resistance and prevalence of extended spectrum beta-lactamase among clinical isolates of gram-negative bacteria in Riyadh

Prevalence of carbapenem-resistant Enterobacterales (CRE) in Saudi Arabia: A systematic review and meta-analysis

Antimicrobial resistance is a significant public health issue. In addressing the threat of multidrug resistant bacterial infections, carbapenems have been used. The carbapenem-resistant Enterobacterales (CRE) are, however, rapidly expanding worldwide. Since the issue of CRE is also a problem in Saudi Arabia, the current meta-analysis was performed to comprehensively evaluate the resistance rates to the main carbapenem antibiotics and determine the actual prevalence of CRE in the country. Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines was followed. Different web databases including PubMed, Scopus, Web of Science, and ScienceDirect were searched for relevant records. Data were extracted, and summary estimates for resistance to carbapenems were calculated using DerSimonian-Laird method of meta-analysis and the random-effects model. From a total of 787 retrieved records, 69 studies were found fully eligible and were included in the final analyses. More than 50 % of all the studies were conducted after 2010, and the most frequently examined members of the Enterobacterales were Escherichia coli and Klebsiella pneumoniae. The pooled prevalence estimate for imipenem resistance was 6.6 % (95 % CI: 4.7-9.2), 9.1 % (95 % CI: 6.7-12.3) for meropenem, and 18.6 % (95 % CI: 11.9-27.9) for ertapenem. High heterogeneity (I2  > 97 %, p < 0.001) was observed for all the estimates. Compared to other regions of the country, there was higher resistance rates in the Al-Qassim and Al-Jouf provinces. Additionally, resistance to ertapenem was as high as 34.2 % in the most recent study period (2021-2024). Proteus spp was the most prevalent CRE (26.2 %). This review highlights an increasing rate of carbapenem resistance among Enterobacterales, emphasizing the need for collaborative efforts to implement strict infection control and prevention measures. Consistent surveillance is indispensable for safeguarding public health, guiding clinical decisions, and strengthening efforts to tackle the challenges of antibiotic resistance.

Increasing Antibiotic Resistance Among Isolates ofEscherichia coliRecovered From Inpatients and Outpatients in a Saudi Arabian Hospital

Objective.

To study the pattern of antibiotic resistance amongEscherichia coliand the trend in resistance during a 6-year period in a Saudi Arabian hospital.

Design.

Retrospective in vitro surveillance study of the antibiotic susceptibility pattern amongE. coliisolates recovered from outpatients and from inpatients.

Setting.

A general hospital in Saudi Arabia.

Patients.

All patients with a culture positive forE. coliduring a 6-year study period.

Results.

A statistically significant increase in antibiotic resistance was observed among outpatient and inpatient isolates ofE, coli.Inpatient isolates were more likely to be resistant to antimicrobial agents. Among isolates from outpatients, 50% were resistant to ampicillin, 33% were resistant to trimethoprim-sulfamethoxazole (TMP-SMZ), and 14% were resistant to ciprofloxacin. Among isolates from inpatients, 63% were resistant to ampicillin, 44% were resistant to TMP-SMZ, and 33% were resistant to ciprofloxacin. There was a low rate of resistance to imipenem (0.3% of isolates), amikacin (2%), and nitrofurantoin (2.4%-6.5%). Resistance to ceftazidime was detected in 9% of outpatient isolates and 17% of inpatient isolates. Multidrug resistance was defined as resistance to 2 or more classes of antibiotics. Multidrug resistance was detected in 2.0%-28.1% of outpatient isolates and 7.4%-39.6% of inpatient isolates, depending on the combination of antimicrobials tested. More isolates were resistant to ampicillin plus TMP-SMZ than to any other combination of antimicrobials.

Conclusion.

The prevalence of antibiotic resistance among outpatient and inpatientE. coliisolates increased during the study period. The rates of antibiotic resistance were statistically significantly higher among inpatient isolates, compared with outpatient isolates. These findings call for wiser use of antibiotics and continued surveillance of antibiotic resistance.

Therapeutic challenges of ESBLS and AmpC beta-lactamase producers in a tertiary care center

BACKGROUND

Resistance to broad-spectrum beta lactams mediated by extended spectrum beta lactamases (ESBLs) and AmpC beta lactamases (AmpC βLs) enzymes is an increasing problem worldwide. Determination of their prevalence is essential to formulate an effective antibiotic policy and hospital infection control measures. Present study was undertaken to determine the prevalence of ESBL and AmpC βL producers in ICU of a tertiary care center.

METHODS

A total of 262 clinical isolates comprising of Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis that were recovered from various clinical specimens over a one year period, were studied. Antibiogram profile was determined to conventionally used antibiotics, along with recommended tests for detection of ESBL and AmpC βL production.

RESULTS

40.07% (105/262) were found to be ESBL producers, 14.8% (39/262) were AmpC bL producers. The coexistence of ESBL and AmpC βL producers was detected in 9.9% (26/262) of the isolates.

CONCLUSION

Screening of multidrug resistant bacteria especially belonging to the Enterobacteriaceae poses considerable therapeutic challenges in critical care patients because of the production of ESBL and AmpC βL. Strategies to keep a check on the emergence of such drug resistant microbes by hospital environmental surveillance and laboratory monitoring should form an important aspect of Hospital Infection control policy guidelines.

Extended Spectrum Beta-lactamase Detection in Gram-negative Bacilli of Nosocomial Origin

BACKGROUND

Resistance to third generation cephalosporins by acquisition and expression of extended spectrum beta lactamase (ESBL) enzymes among gram-negative bacilli is on a rise. The presence of ESBL producing organisms significantly affects the course and outcome of an infection and poses a challenge to infection management worldwide.

MATERIALS AND METHODS

In the period from June 2007 to 2008, we collected 1489 samples from patients suspected of nosocomial infection. The isolates were identified based on colony morphology and biochemical reaction. Gram negative bacilli resistant to third generation cephalosporins were tested for ESBL by double disc synergy test (DDST- a screening test)and then phenotypic confirmatory test. Antimicrobial susceptibility testing was done by modified Kirby Bauer disc diffusion method.

RESULTS

From the sample of 238 gram-negative bacilli, we isolated Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Citrobacter freundii, Proteus mirabilis, Morganella morganii and Enterobacter cloacae. Following both methods, 34% isolates were ESBL-positive. The ESBL producing isolates were significantly resistant (p < 0.01) to ampicillin, piperacillin, piperacillin/tazobactam, trimethoprim/sulfamethoxazole, tetracycline, ciprofloxacin and gentamicin as compared to non-ESBL producers. Multidrug resistance was significantly (p < 0.01) higher (69.14%) in ESBL positive isolates than non-ESBL isolates (21.66%).

CONCLUSION

High prevalence of ESBL in our hospital cannot be ignored. ESBL producers can be detected by DDST and phenotypic confirmatory test with equal efficacy. The sensitivity of screening test improved with the use of more than one antibiotic and addition of one or two antibiotics would not increase cost and labor. We recommend DDST using multiple antibiotics in all microbiology units as a routine screening test.

Increasing antibiotic resistance among isolates of Escherichia coli recovered from inpatients and outpatients in a Saudi Arabian hospital

OBJECTIVE

To study the pattern of antibiotic resistance among Escherichia coli and the trend in resistance during a 6-year period in a Saudi Arabian hospital.

DESIGN

Retrospective in vitro surveillance study of the antibiotic susceptibility pattern among E. coli isolates recovered from outpatients and from inpatients.

SETTING

A general hospital in Saudi Arabia.

PATIENTS

All patients with a culture positive for E. coli during a 6-year study period.

RESULTS

A statistically significant increase in antibiotic resistance was observed among outpatient and inpatient isolates of E. coli. Inpatient isolates were more likely to be resistant to antimicrobial agents. Among isolates from outpatients, 50% were resistant to ampicillin, 33% were resistant to trimethoprim-sulfamethoxazole (TMP-SMZ), and 14% were resistant to ciprofloxacin. Among isolates from inpatients, 63% were resistant to ampicillin, 44% were resistant to TMP-SMZ, and 33% were resistant to ciprofloxacin. There was a low rate of resistance to imipenem (0.3% of isolates), amikacin (2%), and nitrofurantoin (2.4%-6.5%). Resistance to ceftazidime was detected in 9% of outpatient isolates and 17% of inpatient isolates. Multidrug resistance was defined as resistance to 2 or more classes of antibiotics. Multidrug resistance was detected in 2.0%-28.1% of outpatient isolates and 7.4%-39.6% of inpatient isolates, depending on the combination of antimicrobials tested. More isolates were resistant to ampicillin plus TMP-SMZ than to any other combination of antimicrobials.

CONCLUSION

The prevalence of antibiotic resistance among outpatient and inpatient E. coli isolates increased during the study period. The rates of antibiotic resistance were statistically significantly higher among inpatient isolates, compared with outpatient isolates. These findings call for wiser use of antibiotics and continued surveillance of antibiotic resistance.

Extended-spectrum beta-lactamases: a clinical update

Extended-spectrum beta-lactamases (ESBLs) are a rapidly evolving group of beta-lactamases which share the ability to hydrolyze third-generation cephalosporins and aztreonam yet are inhibited by clavulanic acid. Typically, they derive from genes for TEM-1, TEM-2, or SHV-1 by mutations that alter the amino acid configuration around the active site of these beta-lactamases. This extends the spectrum of beta-lactam antibiotics susceptible to hydrolysis by these enzymes. An increasing number of ESBLs not of TEM or SHV lineage have recently been described. The presence of ESBLs carries tremendous clinical significance. The ESBLs are frequently plasmid encoded. Plasmids responsible for ESBL production frequently carry genes encoding resistance to other drug classes (for example, aminoglycosides). Therefore, antibiotic options in the treatment of ESBL-producing organisms are extremely limited. Carbapenems are the treatment of choice for serious infections due to ESBL-producing organisms, yet carbapenem-resistant isolates have recently been reported. ESBL-producing organisms may appear susceptible to some extended-spectrum cephalosporins. However, treatment with such antibiotics has been associated with high failure rates. There is substantial debate as to the optimal method to prevent this occurrence. It has been proposed that cephalosporin breakpoints for the Enterobacteriaceae should be altered so that the need for ESBL detection would be obviated. At present, however, organizations such as the Clinical and Laboratory Standards Institute (formerly the National Committee for Clinical Laboratory Standards) provide guidelines for the detection of ESBLs in klebsiellae and Escherichia coli. In common to all ESBL detection methods is the general principle that the activity of extended-spectrum cephalosporins against ESBL-producing organisms will be enhanced by the presence of clavulanic acid. ESBLs represent an impressive example of the ability of gram-negative bacteria to develop new antibiotic resistance mechanisms in the face of the introduction of new antimicrobial agents.

Extended-spectrum-beta-lactamase-producing Enterobacteriaceae in Yaounde, Cameroon

Organisms producing extended-spectrum beta-lactamases (ESBLs) have been reported in many countries, but there is no information on the prevalence of ESBL-producing members of the family Enterobacteriaceae in Cameroon. A total of 259 Enterobacteriaceae strains were isolated between 1995 and 1998 from patients at the Yaounde Central Hospital in Cameroon. Enterobacterial isolates resistant to extended-spectrum cephalosporin and monobactam were screened for ESBL production by the double-disk (DD) synergy test. Thirty-one (12%) of these Enterobacteriaceae strains were shown to be positive by the DD synergy test, suggesting the presence of ESBLs. Resistance to oxyimino-cephalosporins and monobactams of 12 (38.7%) of the 31 strains-i.e., 6 Klebsiella pneumoniae, 4 Escherichia coli, 1 Citrobacter freundii, and 1 Enterobacter cloacae strain-was transferred to E. coli HK-225 by conjugation. Resistance to gentamicin, gentamicin plus trimethoprim-sulfamethoxazole, or trimethoprim-sulfamethoxazole was cotransferred into 6, 2, and 1 of these transconjugants, respectively. All 12 transconjugants were resistant to amoxicillin, piperacillin, all of the cephalosporins, and aztreonam but remained susceptible to cefoxitin and imipenem. Crude extracts of beta-lactamase-producing transconjugants were able to reduce the diameters of inhibition zones around disks containing penicillins, narrow- to expanded-spectrum cephalosporins or monobactams when tested against a fully susceptible E. coli strain but had no effect on such zones around cefoxitin, imipenem, and amoxicillin-clavulanate disks. The beta-lactamases produced by the 12 tranconjugants turned out to be SHV-12 by DNA sequencing. Therefore, the ESBL SHV-12 is described for the first time in Cameroon.