RESUMO
Background and Objectives: Over the last decade, hospital-acquired infections, particularly in the critical care setting, have become more common, with Gram-negative bacterial infections having the highest prevalence. This study aims to determine the prevalence and antibiotic susceptibility pattern of Pseudomonas species to WHO's, aware class of antibiotics, which are commonly prescribed across various ICU's, medical and surgical wards of our tertiary care teaching hospital. Materials and Methods: This prospective study conducted from January 2021 to June 2022 at a tertiary care centre of central India identified Pseudomonas species from clinical samples using standard procedures and antimicrobial susceptibility testing performed as per Clinical Laboratory Standards Institute (CLSI) guidelines (M100; 32th Edition). Results: A total of 1490 non duplicate Pseudomonas species isolates were grown from 21,019 culture positive clinical samples, of which 1247 were Pseudomonas aeruginosa. Out of these 1247 Pseudomonas aeruginosa 384 were MDR (30.7%). Pseudomonas aeruginosa were most commonly isolated from the pus samples (85%). ICU isolates were significantly more resistant to antibiotics than those from other units. P. aeruginosa strains from ICUs showed the highest rates of resistance to ceftazidime (93.9%). Reserve drug colistin showed good susceptibility (98.2%). All the 18 colistin resistant strains were found to be negative for plasmid mediated mcr-1,2,3 genes. Conclusion: The study shall help to generate and disseminate the data so that proper antibiotic policy can be made for judicious use of Access, Watch and Reserve antibiotics and antibiotic de-escalation plan can be put forth.
RESUMO
Purpose Multidrug-resistant (MDR) organisms are being increasingly reported from India. This study aimed to determine the antibiotic susceptibility pattern of non-fermenting Gram-negative bacilli (NF-GNB) isolated from all the clinical samples to estimate the prevalence of MDR MDR NF-GNB and to screen for colistin-resistance genes among all colistin-resistant strains. Materials and methods This prospective study conducted from January 2021 to July 2022 at a tertiary care teaching hospital in central India identified MDR NF-GNB from clinical samples using standard procedures and antimicrobial susceptibility testing conducted as per Clinical Laboratory Standards Institute (CLSI) guidelines. Colistin-resistant strains identified by broth microdilution were further subjected to detection of plasmid-mediated colistin-resistant genes (mcr-1, mcr-2, mcr-3) by polymerase chain reaction (PCR). Results A total 2,106 NF-GNB were isolated from 21,019 culture positive clinical samples, of which 743 (35%) were MDR. Majority of MDR NF-GNB isolated were from pus (45.50%) followed by blood (20.50%). Out of 743 non-duplicate MDR non-fermenters,the most common were Pseudomonas aeruginosa (51.7%), Acinetobacter baumannii (23.4%),and others (24.9%).Around5.2% Pseudomonas aeruginosa and 2.3% Acinetobacter baumannii were resistant to colistin, and 88.2% were resistant to ceftazidime. Burkholderia cepacia complexwas 100% susceptible to minocycline and least susceptible to ceftazidime (28.6%). Out of 11, 10 (90.9%) Stenotrophomonas maltophilia were susceptible to colistin and least susceptible to ceftazidime and minocycline (27.3%). All 33 colistin-resistant strains (minimal inhibitory concentration ≥ 4 µg/mL) were found to be negative for mcr-1, mcr-2, and mcr-3 genes. Conclusion Our study showed a significantly wide variety of NF-GNB, ranging from Pseudomonas aeruginosa (51.7%), Acinetobacter baumannii (23.4%),to Acinetobacter haemolyticus (4.6%), Pseudomonas putida (0.9%), Elizabethkingia meningoseptica (0.7%), Pseudomonas luteola (0.5%), and Ralstonia pickettii (0.4%), which have not been commonly reported in literature. Of all the non-fermenters isolated in the present study, 35.28% were MDR, raising the concern for rationalizing antibiotic use and improving infection control measures to avert or slow the emergence of antibiotic resistance.
