High Prevalence of Multidrug Resistant Klebsiella Species Isolated from the Yaounde University Teaching Hospital, Cameroon

Background and Purpose: Klebsiella species are amongst the most common causes of a variety of community-acquired and hospital-acquired infections (HAI), characterized by high morbidity and mortality rates. Most infections caused by Klebsiella species are usually treated using antibiotics. The aim of this study was to determine the antimicrobial resistance profile of Klebsiella species isolated from in-patients and out-patients at the Yaounde University Teaching Hospital. The data generated will go a long way to improve on the choice of an adequate empiric antibiotic treatment for infections caused by Klebsiella species. Methodology: A cross-sectional descriptive study was carried out over a period of 6 months, spanning from February 2019 to July 2019 with a sample size of 37 isolates, obtained from 6 different clinical specimens. Identification of isolates was done using API 20E identification system (Biomerieux SA, Lyon, France). Susceptibility to antibiotics was tested as described by Kirby-Bauer in 1956. Inhibition diameters were interpreted according to recommendations from the European Committee on Antimicrobial Susceptibility Testing (EUCAST, 2019). Results and Conclusion: Among the 37 Klebsiella isolates identified, Klebsiella pneumoniae was the most prevalent species isolated with a percentage of 54.1%, followed by Klebsiella rhinoscleromatis 18.9%, Klebsiella ozaenae 16.2% and Klebsiella oxytoca, 10.8%. The resistance pattern of Klebsiella to amoxicillin, amoxicillin/clavulanate, tircacilHow to cite this paper: Mbamyah, E.E.L., Enyeji, F.A., Torimiro, J., Mangum, P., Djuissi, M., Teukam, A.-C., Mesembe, M.T., Ikomey, G.M., Betbeui, A.C., Sedena, D., Baiye, W., Eyoh, A.B. and Gonsu, H.K. (2021) High Prevalence of Multidrug Resistant Klebsiella Species Isolated from the Yaounde University Teaching Hospital, Cameroon. Open Journal of Medical Microbiology, 11, 91-99. https://doi.org/10.4236/ojmm.2021.112008 Received: March 13, 2021 Accepted: June 1, 2021 Published: June 4, 2021 Copyright © 2021 by author(s) and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY 4.0). http://creativecommons.org/licenses/by/4.0/


Introduction
Klebsiella species are found in nature in water, soil and animals and they can colonize medical devices and the healthcare environment [1] [2]. Klebsiella species are among the most common causes of a variety of community-acquired and hospital-acquired infections (HAIs). These diseases cause an increase in morbidity and mortality [3].
They are considered opportunistic pathogens colonizing mucosal surfaces without causing pathology; however, from mucosae Klebsiella may disseminate to other tissues causing life-threatening infections including bronchopneumonia, urinary tract infections (UTIs), bloodstream infections and sepsis [4].
Most infections caused by Klebsiella species are usually treated using antibiotics. The high rate at which antibiotics are used all around the world in human therapy and in veterinary medicine has given rise to antimicrobial resistance [5]. Antimicrobial resistance is associated with increased patient morbidity and mortality and contributes to escalating health care cost and prolonged stay in hospital [6] [7]. Today, antimicrobial resistance is a global public health problem [8] [9]. The aim of this study was to determine the antimicrobial resistance profile of Klebsiella species isolated from the Yaounde University Teaching Hospital. This data will be useful in choosing an adequate antibiotic treatment for infections caused by Klebsiella species.

Results
Thirty seven Klebsiella isolates were identified using the API 20E identification system. Among the species isolated Klebsiella pneumoniae was the most prevalent with 54.1%, followed by Klebsiella rhinoscleromatis 18.9%, Klebsiella ozaenae 16.2% and Klebsiella oxytoca, 10.8% as shown on Figure 1 below. Klebsiella species were most isolated from pus 24.3%, urinary catheter and urine with a frequency of 21.6% each and isolated least from venous catheter 5.4% as shown on Table 1.
The antimicrobial resistance profile of the Klebsiella species to all the antibiotics tested according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST 2019) [10] standards are represented on Figure 2.
The natural resistance of Klebsiella species to ampicillin was confirmed with a 100% resistance. The isolates were most resistant to tircacillin (97.3%) and sulfamethoxazole + trimethoprim (91.9%). The isolates showed the least resistance to imipenem and meropenem with 2.7% each as shown on Figure 2.
Multidrug resistance was observed in 94.6% of the Klebsiella isolates as shown on Figure 3. No wild type was found.

Discussion
In this study the majority of isolates were Klebsiella pneumoniae 20/37 (54.1%).
This trend is similar to previous work by Sunilkumar and collaborators in India (98%) [11] and Hansel and collaborators in the United Kingdom (76%) [12].
The frequency of Klebsiella pneumoniae confirms that it is one of the leading causes of infections [13]. This overall high rate of resistance of the isolates to the penicillins could be explained by the over use of these drugs in the treatment of common infections and ease of drug acquisition without prescription and even from road side vendors.  [17]. This shows that resistance has remained high over time.
The resistance to carbapenems was low for both imipenem and meropenem 1/37 (2.7%). This result is similar to results by Gangoue-Pieboji et al., who in Yaounde had 2% resistance to carbapenems [17]. The low resistance of the isolates to these antibiotics could be explained by the fact that these drugs are reserved as last line treatment, they are expensive and they can be administered only via the intravenous route [18]. The isolates expressed high resistance to the aminoglycosides such as tobramycin 27/37 (73.0%) and gentamicin 28/37 (75.7%) with least resistance recorded to amikacin 5/37 (13.5%). Again there is a general increase in resistance (except for resistance to amikacin) compared to results by Gangoue-Pieboji et al., 2006, who reported a resistance of 35% [17].
The isolates expressed high resistance to sulphamethoxazole + trimetoprim 34/37 (91.9%). This frequency is higher than results obtained by Arafa et al., 2009 who in Algeria reported 73% of their isolates were resistant to sulphometoxazole + trimetoprim [14]. This antibiotic is often used for the treatment of UTI's but the high resistance rate recorded in this study, disqualifies it for such use.
Resistance to ciprofloxacin is considered resistance to all quinolones because of acquisition of at least two mutations in either gyrA or gyrB and parC. These genes are capable of mediating low-level quinolone resistance that causes high-level resistance to arise in the presence of quinolones at therapeutic levels [20].
The emergence of multidrug resistant Klebsiella species has become a major public health concern worldwide and has been associated with outbreaks of infections in developing countries due to the indiscriminate use of antibiotics [21]. An isolate is said to be multidrug resistant if it is resistant to three or more antimicrobial classes. We found that 95% of the isolates were multidrug resistant species. Multidrug resistance in Klebsiella species varies in different parts of the world. In India, 54% was reported [22] and in Nigeria 75.8% [23]. The high level of multidrug resistance in this study could be due to an interplay of other resistance mechanisms co-expressed by the isolates such as extended spectrum betalactamases, quinolone resistance genes and aac(6')-Ib-cr enzymes which hydrolyze quinolones and aminoglycosides. Furthermore, prior antibiotic use in hospitals or through auto-medication, overuse of antibiotics in livestock and fish farming, poor infection control in health care facilitates and poor hygiene and Open Journal of Medical Microbiology sanitation exercebates multidrug resistance.
This study however had some limitations. The sample size was small as isolates were collected from only one hospital, the Yaounde University Teaching Hospital. This study needs to be extended to other hospitals in Yaounde for a longer period to better understand resistance trends in Yaounde. For the purpose of infection control and clinical relevance of the results, it would be necessary for the resistance phenotypes to be characterized.

Conclusion
This study shows that the level of multidrug resistance is high. The isolates expressed good sensitivity to the carbapenems, piperacillin + tazobactam, amikacin and high resistance to all other antimicrobials tested. This indicates that with the exception of a few antibiotics, commonly used affordable antibiotics may not treat infections caused by Klebsiella spp. Therefore, antimicrobial susceptibility testing prior to prescriptions should be encouraged and sensitization of the population about the consequences of antibiotic abuse and auto medication should be enforced as a means to curb antimicrobial resistance. The surveillance of antimicrobial resistance should be put in place to monitor clinically relevant isolates.