Extended Spectrum Beta Lactamase Profile of Citrobacter Species Isolated from Various Samples in the North East Coast of Tamil Nadu, India: A Cross-sectional Study

Abstract

Introduction: Citrobacter species play a significant role in causing hospital-acquired infections, especially those affecting the urinary and respiratory systems, and they are commonly present in faeces. Healthcare systems are facing a major challenge due to the rise of antibiotic-resistant Gram-negative infections resistant to antibiotics. Aim: To identify the genotypic characterisation of the resistant gene blaTEM-1 in Citrobacter spp. obtained from a range of clinical samples. This investigation seeks to provide insights into the patterns of antibiotic resistance exhibited by these bacteria. Materials and Methods: This cross-sectional study was conducted between August 2021 and February 2022. Preliminary examinations included screening as well as confirmatory tests for Extended Spectrum Beta Lactamase (ESBL) production, which were confirmed by the combination disk method and double disc synergy test. Genotypic detection of the blaTEM-1 gene was done using the Polymerase Chain Reaction (PCR) technique. Demographic parameters like gender and age were assessed. Statistical analysis was done using the Statistical Package for the Social Sciences (SPSS) Software version 21.0. Results: Citrobacter koseri (66 isolates, 54.5%) was found to be the predominant species among the Citrobacter spp., followed by Citrobacter freundii (55 isolates, 45.5%). Urine samples were the primary source of Citrobacter spp. isolates, comprising 52 isolates (43%) of the total. In this study, the prevalence of ESBL producers was reported to be 49 isolates (77.8%) identified as ESBL producers. Tigecycline demonstrated a 100% effectiveness rate, followed by Piperacillin-Tazobactam (96% sensitivity) and Amikacin (95% sensitivity). Out of the 20 Citrobacter spp. isolates that tested positive for ESBL, 15 isolates (75%) were found to be positive for blaTEM-1. Conclusion: The results of this study provide insight into the changing patterns of antibiotic resistance in Citrobacter spp., with particular emphasis on ESBL profiles. Thus, it is imperative to implement intervention techniques to reduce the ongoing selection and spread of these more resistant bacteria, as well as efficient infection-control measures to manage epidemics. These results advance the comprehension of antibiotic resistance patterns and guide initiatives to combat the increasing threat of antibiotic resistance.

Keywords

• antimicrobial resistance
• citrobacter freundii
• citrobacter koseri
• extended spectrum beta lactamase producers