Emergence of colistin-resistant gram-negative rods in intensive care units: A cross-sectional study from a developing country

Abstract

Objectives: To determine the clinical features, outcomes, and factors associated with the emergence of colistin-resistant gram-negative rods isolated from patients admitted to intensive care units. Methods: This cross-sectional study was conducted at the intensive care units of Liaquat National Hospital, from April 2019 to February 2020. Gram-negative rods resistant to colistin with minimum inhibitory concentrations ⩾ 4 mcg/mL according to Clinical and Laboratory Standards Institute criteria as reported in cultures were included. Clinical, demographical data and treatment given were recorded and analyzed using SPSS version 25. Results: A total of 93 patients were included; 58.1% were males. The mean age of patients was 59.48 ± 18.36 years. The most common organism isolated was Klebsiella pneumoniae (91.4%). The most common specimen was the tracheal (62.4%). Ventilator-acquired pneumonia was seen in 38.7%. The most common co-morbid disease seen in patients was diabetes (41%); 77% had a symptomatic infection and were treated with a combination of 2 or more antibiotics, most commonly meropenem plus fosfomycin. The most common susceptible antibiotics were fosfomycin (72%) and tigecycline (50.5%). Mean intensive care unit stay and total duration of hospital stay were prolonged (16.83 ± 12.93 and 23.34 ± 17.52 days, respectively). Forty-eight (62.3%) patients with symptomatic infection with colistin-resistant isolates were treated and discharged, and mortality was seen in 23 (29.9%). A significant association was found between mortality and symptomatic infection, endotracheal intubation with mechanical ventilation (p = 0.003), and a prolonged hospital stay of >20 days (p = 0.041). Conclusion: Colistin-resistant gram-negative rods pose a significant problem especially in developing countries because of limited therapeutic options. Stringent infection control and comprehensive antimicrobial stewardship programs are needed to overcome this challenge.

Study of Colistin Resistant Gram Negative Organism in Hospitalized Patients: A Retrospective Study

“…In a study by Syed et al, K. pneumoniae was the most common organism isolated (91.4%), followed by E. coli (11%), P. aeruginosa (5.4%), and A. baumannii (4.3%). 3 Arjun et al found that K. pneumoniae constituted the majority of isolates (87.5%), with smaller numbers of other organisms. The variations in these findings across studies highlight the regional differences in microbial prevalence.…”

“…They reported that 41 (44.1%) patients were intubated and mechanically ventilated, 81 (87.1%) patients had urinary catheters, and central lines were inserted in 71 (76.3%) patients. 3 Yang et al also found that indwelling urinary catheters, mechanical ventilation, recent β-lactam-β-lactamase inhibitors, fourth-generation cephalosporins, and/or carbapenem therapy were independent risk factors for colistin-resistant K. pneumoniae infection. 5 …”

“…In a similar study conducted by Syed et al, Diabetes mellitus was present in 39 (41.9%) patients, CKD in 22 (23.7%) patients, malignancy in 1 (1.1%), and long-standing immunosuppressive therapy in 4 (4.3%) patients with colistin-resistant isolates. 3 Richter et al conducted a retrospective study involving positive cultures from any source over a 6-year period to assess the risk of infection with colistin-resistant gram-negative isolates, with a focus on K. pneumoniae . They found that a prior history of antibiotics uses within the last 3 months, mainly carbapenem uses, and a prolonged admission duration were significantly associated with colistin resistance.…”

The battle against colistin-resistant E. coli and the need for a one health approach

“…The emergence of colistin resistance in E. coli can be attributed to several factors: Overuse and misuse of antibiotics in both humans [ 21 ] and veterinary medicine [ 22 ] have played a significant role. The inappropriate use of colistin in agriculture as a growth promoter in livestock has contributed to the selection of resistant strains.…”