Clinical Characteristics and Risk Factors of CarbapenemResistant Enterobacteriaceae: A Case-Control Study in a Tertiary Hospital in Malaysia

@#Introduction: Carbapenem-resistant Enterobacteriaceae (CRE) is increasingly reported worldwide causing serious threats to healthcare. This study aimed to identify the common organisms associated with CRE, the clinical characteristics and risk factors for acquiring CRE infection and colonisation among hospitalised patients. Methods: This is a matched, case-control study. Patients aged 18 years and above whom were hospitalised from January 2019 to December 2019 and had CRE isolated from clinical specimens were matched with carbapenem-susceptible controls (CSE), based on gender and age. Univariate and multivariate statistical analysis was performed. Results: Among 184 patients, Klebsiella pneumoniae was the most common organism causing CRE infection and colonisation. Chronic kidney disease (p=0.025, OR:3.12, 95% CI:1.15-8.41), urinary catheterisation (p=0.005, OR:3.67, 95% CI:1.49- 9.00), prior use of cephalosporin (p<0.001, OR:4.69, 95% CI:1.96–11.22) and beta-lactam combination agent (p<0.001, OR:7.18, 95% CI:2.98-17.26) were identified as the independent risk factors. Conclusion: Chronic kidney disease, urinary catheterisation, prior use of cephalosporin and beta-lactam combination agents were independently associated with CRE infection and colonisation. These findings enable targeting potential CRE cohorts, hence, necessitate early undertaking of prevention measures to delay the onset of CRE. A rigorous effort by antibiotic stewardship an infection control team are pivotal.

Conventional versus molecular detection of Chlamydia trachomatis and Neisseria gonorrhoeae among males in a sexually transmitted infections clinic

Chlamydia trachomatis and Neisseria gonorrhoeae are important bacterial pathogens of sexually transmitted infections (STIs) worldwide. This study sought to compare the analytical sensitivity and specificity of conventional methods against a rapid molecular method in detecting STIs caused by these bacteria. Methods: Ninety five first-time male attendees of the Genito-urinary Medicine Clinic in Hospital Kuala Lumpur were included in this cross-sectional study. The detection of C. trachomatis was achieved through direct fluorescence antibody (DFA) staining of urethral swabs and real-time polymerase chain reaction testing (Xpert® CT/NG assay) on urine specimens. N. gonorrhoeae was detected through Gram staining and culture of urethral swabs and Xpert® CT/ NG assay on urine specimens. Results: From the Xpert® CT/NG results, 11 (11.6%) attendees had chlamydia, 23 (24.2%) had gonorrhoea and 8 (8.4%) had both STIs. The sensitivity and specificity of DFA in detecting chlamydia compared to Xpert® CT/NG were 5.3% (95% CI: 0-28) and 94.7% (95% CI: 86-98), respectively. For gonorrhoea, the sensitivity and specificity of Gram staining were 90.3% (95% CI: 73-98) and 95.3% (86-99), respectively, whereas the sensitivity and specificity of culture compared to Xpert® CT/NG were 32.2% (95% CI: 17-51) and 100% (95% CI: 93-100), respectively. Conclusion: Although Gram-stained urethral swab smears are sensitive enough to be retained as a screening tool for gonorrhoea, culture as well as DFA lack sensitivity and are poorly suited to screen for gonorrhoea and chlamydia, respectively. However, owing to their high specificity, conventional detection methods are still suitable as confirmatory tests for gonorrhoea and chlamydia.

Molecular characterization of carbapenemase and cephalosporinase genes among clinical isolates of Acinetobacter baumannii in a tertiary medical centre in Malaysia.

Antimicrobial resistance in Acinetobacter baumannii is a growing public health concern and an important pathogen in nosocomial infections. We investigated the genes involved in resistance to carbapenems and cephalosporins in clinical A. baumannii isolates from a tertiary medical centre in Malaysia. A. baumannii was isolated from 167 clinical specimens and identified by sequencing of the 16S rRNA and rpoB genes. The MIC for imipenem, meropenem, ceftazidime and cefepime were determined by the E-test method. The presence of carbapenemase and cephalosporinase genes was investigated by PCR. The isolates were predominantly nonsusceptible to carbapenems and cephalosporins (>70 %) with high MIC values. ISAba1 was detected in all carbapenem-nonsusceptible A. baumannii harbouring the blaOXA-23-like gene. The presence of blaOXA-51-like and ISAba1 upstream of blaOXA-51 was not associated with nonsusceptibility to carbapenems. A. baumannii isolates harbouring ISAba1-blaADC (85.8 %) were significantly associated with nonsusceptibility to cephalosporins (P<0.0001). However, ISAba1-blaADC was not detected in a minority (<10 %) of the isolates which were nonsusceptible to cephalosporins. The acquired OXA-23 enzymes were responsible for nonsusceptibility to carbapenems in our clinical A. baumannii isolates and warrant continuous surveillance to prevent further dissemination of this antibiotic resistance gene. The presence of ISAba1 upstream of the blaADC was a determinant for cephalosporin resistance. However, the absence of this ISAba1-blaADC in some of the isolates may suggest other resistance mechanisms and need further investigation.