Resistance trends of the Gram-negative ESKAPE pathogens Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter spp. over five years: Northdale, Grey’s and Harry Gwala State Hospitals

Abstract

Background and aim Antimicrobial resistance is one of the greatest risks to human health in the modern era and a major health concern worldwide. Previous studies have shown that certain strains of bacteria have developed resistance to almost all antibiotics. The study aimed to investigate the antimicrobial resistance trends of the Gram-negative ESKAPE (Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter species) pathogens in the current era, determine the most prevalent microorganism, and determine which ward harbors the most microorganisms and specific isolates in the Pietermaritzburg (PMB) area of the KwaZulu- Natal (KZN), South Africa (SA), over five years. Antimicrobial resistance is known to be mostly common in patients of long-term acute care (LTAC) facilities due to a multitude of known risk factors. However, there has not been a thorough description and/or investigation of how antimicrobial resistance is at these selected PMB state hospitals. Methodology Retrospective data from 1 February 2017 to 31 January 2022 from the Pietermaritzburg National Health Laboratory Service (NHLS) hospitals, namely Grey’s, Harry Gwala, and Northdale Hospitals, were collected via the Corporate Data Warehouse (CDW) from 10 303 isolates to assess the resistance trends of Gram-negative ESKAPE (Enterococcus faecium; Staphylococcus aureus; Klebsiella pneumoniae; Acinetobacter baumannii; Pseudomonas aeruginosa; Enterobacter species) pathogens from various clinical samples such as wound swabs, blood, sputum, urine, Central Venous Catheter (CVC) tips, soft tissue, and other body fluids (ascitic and synovial fluid, Cerebrospinal fluid). These samples originated from patients in the hospital wards, intensive care units, and outpatient departments and were previously delivered to the lab for routine diagnostic examinations. Good laboratory practices for microscopy, culture, and susceptibility testing, or isolation, and identification were followed. Once in the NHLS TrakCare database, the test results were retained in the CDW. Information about people diagnosed within the allotted time frame with infections brought on by Enterobacter species, Pseudomonas aeruginosa (P. aeruginosa), Klebsiella pneumoniae (K. pneumoniae), and Acinetobacter baumannii (A. baumannii) complex was sought. The results of microscopy, culture, antibiotic sensitivity testing, and biochemical tests where specimens were tested, were also received. The NHLS laboratory tests for K. pneumoniae, A. baumannii complex, P. aeruginosa, and Enterobacter species were reported. Proper data storage in the Figshare system was always maintained in compliance with the POPIA Act. Results and Discussion Among the 10 303 isolates, the Klebsiella genus was predominant among all ESKAPE isolates, with n = 4 088 (39,7%). The Enterobacter genus played a limited role, with E. cloacae complex being the most frequent in the genus (1 506, 14,6%) and E. aerogenes with the least contribution within the ESKAPE pathogen group (240, 2,3%). Overall, most isolates were resistant to third generation cephalosporins, including ceftazidime and ceftriaxone, indicative of extended spectrum beta lactamase (ESBL) production. The findings of this study correlate well with a study done in 2011– 2015 in the same area (PMB), which states that ceftriaxone (8 326; 58,3%) and ceftazidime (7 412; 51,9%) were among the third generation cephalosporins that more than 50% of isolates were resistant to (Ramsamy et al., 2018). Colistin and tobramycin had the least overall resistance of 2,5% and 8,5%, respectively. This compares well with a 3,1% colistin resistance found in a recent study (Uzairue et al., 2022). Ertapenem and nitrofurantoin were the third-most effective antimicrobial agents, with both an overall resistance percentage of 9,5%. Among drugs of betalactam inhibitor combinations/beta-lactam, piperacillin/tazobactam (TZP) was better active against the isolates, with a resistance rate of 25,2%, which is indicative of the fact that ESBLs were sensitive to TZP. Even though P. aeruginosa showed low resistance to the tested antimicrobial agents during the period of this study, it showed a 98,8% resistance to tigecycline. Tigecycline does not consistently suppress P. aeruginosa; however, it appears to be an effective antimicrobial agent in extremely ill and immunocompromised patients. Regarding the prevalence of these resistant organisms according to wards, our data indicated that the ICU and male surgical ward had the highest rates of resistant isolates at 12,1% and 6,9%, respectively. This is in line with recent research findings, which showed that extended hospital stays, and high usage of invasive procedures contribute to the prevalence of nosocomial and invasive infections in intensive care units (Abubakar and Salman, 2024; Greatorex and Oosthuizen, 2015). The high resistance trend found in this study supports the need for increased surveillance of hospitalized patients. Conclusion This research presents a detailed analysis of the five-year resistance patterns of Gram-negative ESKAPE bacteria in PMB state hospitals. For example, these data show that the A. baumannii Complex shows significant fluctuations in resistance rates to numerous antibiotics. These results emphasize the need for effective antibiotic stewardship, robust infection control techniques, and continuous surveillance as antibiotic resistance grows. PMB state hospitals can enhance patient outcomes and public health by implementing these suggestions and controlling and lowering the prevalence of antibiotic-resistant illnesses. The global threat posed by these resistant pathogens is confirmed by the consistency of our results with earlier research, which highlights the importance of collaboration in addressing this public health emergency. This analysis reveals significant changes in resistance rates for several antibiotics, particularly in the A. baumannii complex. These findings underscore the need for continued surveillance, effective antibiotic stewardship, and robust infection control measures to address the growing challenge of antibiotic resistance.