Antibiotic Susceptibility Testing (AST) Practices in India: Need for a National AST Forum

Abstract

BackgroundAccurate interpretation of antibiotic susceptibility testing (AST) is one of the most crucial functions of the microbiology laboratory. However, its performance depends on a number of critical factors. We conducted a status survey to understand the existing practices in Indian laboratories that have a potential to influence performance of AST. MethodWe developed a 22-point online survey questionnaire on information about respondent's specifications, use of AST consumables, existing quality control protocols, and matters of contention in AST practices, and sent it by Google forms to 362 clinical microbiologists (holding MD or DNB certification). Participation was voluntary. Results were analyzed using descriptive statistics. ResultsAmong 362, a total of 103 returned the questionnaire. The first 100 responses that were complete (all 22 questions answered) were analyzed. Respondents were from medical colleges (61%), private hospitals (26%), and stand-alone laboratories (13%). Analysis revealed that the Clinical & Laboratory Standards Institute (CLSI) guidelines were followed by all. Overall, 54% used disc diffusion as the primary method for performing AST. For the internal quality control testing of media and AST, 24% and 16% had adequate testing components and frequency, respectively. For performing AST of colistin, broth microdilution was used by 19%. Also, 86% participated in external quality control programs, and 54% respondents were dissatisfied or unsure about the development of competencies in AST methodology during their postgraduate training. ConclusionThis survey reveals that potential gaps exist in the performance parameters and internal quality control of AST. There is an urgent need for harmonization in AST performance and postgraduate training in clinical microbiology in India.

In vitro activity of cefiderocol against comparators (ceftazidime-avibactam, ceftazidime-avibactam/ aztreonam combination, and colistin) against clinical isolates of meropenem-resistant Klebsiella pneumoniae from India

“…Disk diffusion, gradient testing, or semi-automated commercial testing panels (e.g., VITEK-2) are not recommended for testing this drug. The only recommended method is broth microdilution, which is not widely available, especially in resource-limited settings ( 15 ). Semi-automated methods such as VITEK-2 are used in such settings for performing susceptibility of CST.…”