Insight into Stenotrophomonas maltophilia Infections in a Tertiary Care Teaching Hospital in Western India and Review of Literature: A Retrospective Observational Study

Introduction: Stenotrophomonas maltophilia (S. maltophilia) is a ubiquitous and opportunistic pathogen of growing importance. This gram -negative, non fermenter is widely distributed in moist hospital environments. It is intrinsically resistant to a number of antibiotics, making it a challenge both for the clinician and the microbiologist. Very sparse data is available from Western India regarding this emerging pathogen. Aim: To determine the prevalence and spectrum of infections caused by S. maltophilia and to provide an overview of associated co -morbidities, antibiotic susceptibility pattern of these isolates, and clinical outcomes. Materials and Methods: This retrospective observational study was carried out in a tertiary care private hospital (Mahatma Gandhi Hospital) in Jaipur, Rajasthan, India over a period of one year (July 2021 -June 2022). A total of 11,170 samples were received in the microbiology laboratory for bacterial culture and susceptibility testing during the study period and processed as per standard protocols. Only one isolate per patient was included for the purpose of the study. Culture identification and antibiotic susceptibility testing was done using the VITEK-2 automated system. Data regarding patients' demographic profile, epidemiological profile, baseline characteristics, comorbidities, laboratory findings, and clinical outcome were tabulated in an Excel worksheet and analysed. All statistical analysis was done using the Software Statistical Package for the Social Sciences (SPSS) version 20.0. Results: Fourteen patients were found to have S. maltophilia infection during the study period. The majority of patients had respiratory tract infection and bacteraemia. All isolates were from inpatients, more than two-thirds being from the Intensive Care Unit (ICU). A high level of susceptibility was seen to routinely recommended drugs, with 100%, 93% and 79% being susceptible to minocycline, levofloxacin and co-trimoxazole, respectively. All patients (except one) were successfully managed and discharged. Conclusion: S. maltophilia is an emerging opportunistic pathogen and is associated with a plethora of clinical conditions. Early and accurate diagnosis by embracing automation in microbiology laboratories is essential to identify this pathogen. S. maltophilia infections have a favourable outcome when diagnosed and treated timely.