Bacteria profiles and antimicrobial susceptibility pattern of isolates from beds and door handles of hospital wards in Tiko Health District, Cameroon

¹Department of Medical Laboratory Science, Faculty of Health Sciences, University of Buea, Buea, Cameroon, ²Department of Applied Science, School of Engineering and Applied Sciences, Institut Universitaire de La Côte, Douala, Cameroon, ³Department of Medical Laboratory Science, School of Medical and Biomedical Sciences, Maflekumen Higher Institute of Health Sciences Tiko, Tiko, Cameroon

^&Corresponding author
Njeodo Njongang Vigny, Department of Medical Laboratory Science, Faculty of Health Sciences, University of Buea, Buea, Cameroon

Introduction    

Hospital-acquired infections (HAIs), also known as nosocomial infections, are illnesses that occur 48 hours following a hospital visit or during hospitalization [1]. Bacteria, viruses, fungi, and parasites are linked to HAIs. In addition, Staphylococcus aureus, Enterobacteria, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Clostridium difficile are the primary bacterial agents. Aspergillus and candida are also related to HAIs, while rotavirus, hepatitis B and C viruses, and influenza virus are viruses that cause HAIs [2,3]. A diverse range of microorganisms can be found in hospital environments, with a few pathogenic bacterial strains frequently colonizing regularly touched areas such as door knobs, beds, bed rails, trays, and tables among others [4]. According to research done in Douala, Garoua, and Dschang, surgical site infection is the most common of the HAIs, which also include respiratory, gastrointestinal, bloodstream, and urinary tract infections. In addition, the surgical ward had a higher prevalence of skin and soft tissue site infections than urinary and bedsore infections [5,6]. Because of patients' irrational and excessive use of antibiotics, bacteria that cause HAIs most frequently have become resistant to them [7].

According to a meta-analysis, the prevalence of HAIs is 0.14% globally and is increasing by 0.06% a year [8]. According to the same study, E. coli had the highest infection rate among patients when compared to Coagulase-negative Staphylococci (CoNS), Staphylococcus spp., and P. aeruginosa. Additionally, the global prevalence of HAIs was higher in men than in women [8]. The Americas and the West Pacific had the lowest rates of HAIs, while Africa had the greatest rate [8]. Furthermore, the prevalence of HAIs in Africa (12.76%) is more than twice as high as that seen in developed nations [9]. Based on positive culture results for HAIs in records from the microbiology unit, gram-negative bacteria (K. pneumoniae, Escherichia coli, P. aeruginosa, Acinetobacter baumannii, and Citrobacter) were the most prevalent microorganisms in this region and accounted for 40%-100% of infections [9].

Research carried out in Nepal, Morocco, Ghana, Algeria, and the south, southwest, and northwest Ethiopia has revealed S. aureus to be the most common bacterial pathogen found on hospital ward door handles [10-16]. Other bacterial isolates have also been discovered in several of these investigations, including P. aeruginosa, Enterobacter, CoNS, Staphylococcus saprophticus, Klebsiella spp., and Acinetobacter baumannii [11,13,14,16]. On hospital ward beds, S. aureus and CoNS have frequently been found [13-16]. Conversely, there have not been many reports of Acinetobacter, K. rhnioscleromates, Enterobacter, and E. coli [14,16,17]. The most effective antibiotics against S. aureus, according to recent data from Southern Ethiopia, Nepal, Morocco, and Ghana, are ampicillin, gentamycin, levofloxacin, and ciprofloxacin, in that order [10-12,16].

At the University Teaching Hospital in Yaoundé, Cameroon, the cumulative incidence rate (19.21%) and death rate (28%) of HAIs are high [1]. Furthermore, 44.7% (25/85) of the hospital's wards had the greatest rate of bacterial contamination [18]. Data on microorganisms found on hospital wards' beds and door handles, as well as their patterns of antibiotic susceptibility, are scarce in Cameroon. Thus, the purpose of this study was to evaluate bacterial isolates from beds and door handles in hospital wards and determine their antibiotic susceptibility patterns in the Tiko health district of Cameroon.

Methods     

Study duration, setting, and sampling technique: this was a cross-sectional study that was conducted in Tiko Health District, for over six months, from November 2021 to April 2022, precisely at Regina Pacis Hospital, Private Medical Insurance (PMI) Hospital, COMWEL Clinic, and Tiko District Hospital. These four health facilities belong to the peripheral level in the structure of the health system in Cameroon. The Tiko Health District is one of the 18 health districts in the Southwest Region of Cameroon. The majority of the people who visit these hospitals are farmers and plantation workers [19]. The health district is found in the Southwest Region of Cameroon and has about 334,647 inhabitants distributed in eight health areas with a total surface area of 4840 km² [20]. It has mean daily temperatures ranging from 28 to 33°C, which accounts for the dry nature of the study site [21]. It also has three urban settlements, namely Tiko, Likomba, and Mutengene, along with the following boundaries: Buea Health District (North), Bonaberi Health District (South), Dibombari Health District (East), and Limbe Health District (West), characterized by activities such as trading, farming, and fishing [20]. Maflekumen Teaching Laboratory is a site reserved for daily practicals on campus at the Maflekumen Higher Institute of Health Sciences. It has microscopes, an incubator, and a staining section with several cupboards in which stains, petri dishes, and slides are stored.

A total of 20 door handles and 40 beds were selected in the Tiko Health District of Cameroon using a multistage sampling technique. In the first stage, four health areas were randomly selected from the 8 health areas (Mutengene, Holforth, Kange, Tiko Town, Likomba, Misselele, Mondoni, and Mudeka) in the Tiko Health District. These selected health areas were Likomba, Tiko Town, Mutengene, and Holforth. In the next stage, a list of health facilities was compiled for each health area. The distribution of health facilities in the health areas was: Tiko town (COMWEL clinic), Holforth (PMI hospital), Mutengene (Baptist hospital, Atlantic hospital, Regina Pacis, and Centralized Medical hospital), and Likomba (Central clinic, Cottage hospital, Tiko district hospital, and Sone clinic). In stage 3, a hospital was randomly selected from each of the four health areas, resulting in the following facilities: Regina Pacis Hospital, PMI Hospital, COMWEL Clinic, and Tiko District Hospital. Five-door handles and 10 beds were randomly selected from every hospital in the final stage.

Inclusion and exclusion criteria: beds and door handles of wards in Regina Pacis Hospital, PMI Hospital, COMWEL Clinic, and Tiko District Hospital were included. Nonetheless, beds and door handles outside the wards were excluded.

Sample collection and processing

Sample collection: the surfaces of 40 beds and 20 door handles in the hospital wards were swabbed using sterile swab sticks moistened with 0.9% w/v physiologic saline. The samples (15 each from four hospitals) were collected using swab sticks, which were immediately put back in their sterile plastic tubes after collection. Face masks, gloves, and laboratory coats were worn to ensure the sterility of the samples. The tubes were finally transported in zip-lock polythene bags within 20-30 minutes to the Maflekumen Teaching Laboratory for processing.

Sample processing

Sample culture: the swabbed samples were inoculated on CLED agar, blood agar, and MacConkey agar. Each agar was prepared by weighing it in powder form using an electronic balance and dissolving it in a measurable amount of distilled water, following the manufacturer´s instructions. During the preparation of the culture media, quality control was maintained by autoclaving the culture media to ensure sterility. It was later incubated aerobically at 37°C for 24 hours. Culture plates were inspected to identify visible bacteria colonies. Presumptive identifications of bacteria were done based on colony characteristics and Gram reactions. Confirmatory tests were done based on the enzymatic and biochemical reactions of the organisms using various reagents and enzymes. The pH of the enzymes and biochemical reagents was tested using pH papers to ensure quality control. They include the Catalase test (exclusively used to identify S. aureus and Bacillus spp.), the Nagler reaction (biochemical test for C. perfringens), the analytical profile index (biochemical test for Enterobacteria spp.), and the Indole test (commonly used to detect enterobacteria).

Antimicrobial susceptibility testing: antimicrobial susceptibility testing was performed for each bacterial isolate on nutrient agar using the Kirby-Bauer disk diffusion technique. Furthermore, three to five selected colonies of a pure culture of bacteria were transferred to a tube containing 5 ml of sterile normal saline and mixed gently to form a homogenous suspension until the turbidity of the suspension was adjusted to 0.5 McFarland [22]. A sterile cotton swab was used to remove the excess suspension by rotating the swab against the surface of the tube. The swab was then used to distribute the bacteria evenly over the surface of the nutrient agar. The inoculated plates were left at room temperature to dry for 3-5 minutes, and a set of antibiotic discs was placed on the inoculated plates using sterile forceps. The plates were allowed to stand for 30 minutes and later incubated at 35°C for 16 to 18 hours. Moreover, the observed zones of inhibition around the antibiotic discs were compared with the standard zones of inhibition for each bacterial isolate. If an observed zone was equal to or greater than the standard zone, the bacterial isolate was considered sensitive to a specific antibiotic. However, a bacterial isolate was described as resistant if otherwise. Each diameter of the observed zone of inhibition for a specific disc was measured using a ruler in centimeters [22].

Data analysis: data were entered into Microsoft Excel and exported into SPSS (Statistical Package for Social Sciences) version 22 for analysis. Qualitative data were presented on bar charts, while quantitative data were summarized and presented in a table.

Ethical approval statement: an approval letter to conduct this study was obtained from Maflekumen Higher Institute of Health Sciences Tiko. In addition, administrative authorizations were obtained from the district medical officer in Tiko and a director from each of the four hospitals.

Results     

Frequencies of bacterial isolates from beds and door handles of wards in Tiko Health District: the Tiko health District's hospital wards' beds and door knobs were found to harbour S. aureus, C. perfringens, K. pneumoniae, Clostridium spp., and Bacillus spp. Figure 1 illustrates that of the 60 bacterial isolates (found on hospital beds and door knobs in the Tiko Health District), the most common species were Bacillus spp. 15 (25%) and Staphylococcus aureus 21 (35%).

Frequencies of bacterial isolates from hospital wards by beds and door handles: compared to other bacterial isolates, S. aureus (42.5%, 17/40) and Bacillus spp. (27.5%, 11/40) were identified from ward beds more frequently. But the most frequent bacterial isolate from ward door handles was C. perfringens (35%, 7/20) (Figure 2).

Frequencies of bacterial isolates from beds and door handles of wards by hospital: Regina Pacis Hospital had a 53.3% prevalence of S. aureus on beds and door handles (8/15) and the COMWEL clinic had a similar prevalence (53.3%, 8/15). However, as Figure 3 illustrates, Bacillus spp. was isolated in Tiko District Hospital the most frequently (53.3%, 8/15).

Antimicrobial susceptibility patterns of Staphylococcus aureus, Clostridium perfringes, Bacillus species, and Klebsiella pneumoniae: S. aureus (a total of 21 isolates) were sensitive to gentamycin 20 (95.2%), azithromycin 20 (95.2%), ampicillin 9 (42.9%), and chloramphenicol 8 (38.1%). Additionally, as indicated in Table 1, Bacillus spp. (a total of 15 isolates) exhibited susceptibility to gentamycin 13 (86.7%) and chloramphenicol 4 (26.7%). Table 1 displays multidrug resistance in S. aureus against bacitracin 21 (100%), and tetracycline 12 (57.1%), while Bacillus spp. displayed multidrug resistance against bacitracin 15 (100%), cephalothin 10 (66.7%), and tetracycline 1 (6.6%).

Discussion     

We assessed bacterial isolates from beds and door handles of hospital wards in Tiko Health District and determined their antimicrobial susceptibility patterns. The following isolates: S. aureus, C. perfringens, K. pneumoniae, Clostridium spp., and Bacillus spp. were found in the Tiko Health District. Our finding showed that S. aureus 35% (21/60) and Bacillus spp. 25% (15/60) were the most dominant bacterial pathogens on beds and door handles of hospital wards. S. aureus (42.5%, 17/40) was the predominant contaminant on beds. On the contrary, C. perfringens (35% (7/20) was the most frequent bacterial isolate from door handles. In addition, S. aureus (n = 21) was most sensitive to gentamycin 20 (95.2%) and azithromycin 20 (95.2%), followed by ampicillin 9 (42.9%) and chloramphenicol 8 (38.1%). In contrast, the sensitivity rates of C. perfringes (n = 8) were 6 (75%) for gentamycin, 6 (75%) for chloramphenicol, and 4 (50%) for azithromycin. Regularly touched surfaces, such as hospital ward beds and door handles, are potential sources of nosocomial infections. These sites increase the contamination risk among susceptible hosts [23]. In the current investigation, 60 hospital ward beds and door handles were swabbed, and bacterial pathogens including S. aureus, C. perfringes, K. pneumoniae, Clostridium spp., and Bacillus spp. were detected.

In the current investigation, 60 hospital ward beds and door handles were swabbed, and bacterial pathogens including S. aureus, C. perfringens, K. pneumoniae, Clostridium spp., and Bacillus spp. were detected. Also, C. perfringens and Clostridium spp. were relatively new bacterial isolates from door handles and beds in hospital wards reported in the current study. This finding suggests poor hygienic practices by patients or health professionals before and after visiting the hospital toilets. C. perfringens is a spore-forming bacterium that is widely distributed in the environment and frequently occurs in the intestines of humans. Moreover, the spores of the bacterium are found in areas subject to human fecal pollution. Our result is in support of studies by Saadi and colleagues in Algeria and Tagoe et al. in Ghana, which reported S. aureus, K. pneumoniae, and Bacillus spp., among other bacterial species, isolated from patient beds and door handles in hospital wards [14,24]. Furthermore, similar bacterial isolates were detected on beds and door handles in Morocco and Nigeria [16,25]. On the contrary, our evidence is inconsistent with studies conducted in Ethiopia and Ukraine, which reported S. aureus as the only similar bacterial isolate [11,26]. Also, a contradictory finding was reported by a study in Cameroon, which showed that K. pneumoniae, E. cloacae, and P. aeruginosa are dominant bacterial contaminants on beds and door handles of hospital wards [27]. This disparity may be due to different sampling times, sampling techniques, culture methodologies, and hospital wards.

S. aureus constitutes part of the normal human flora, inhabiting the skin and mucous membranes, and is regularly shed into the hospital environment by patients and medical personnel. Taken together, S. aureus 21 (35%) was the most dominant bacterial contaminant in the current study. Staphylococci pathogens are dominant on surfaces because they can express adhesion factors and fatty acid-modifying enzymes for biofilm formation and modify anti-bacterial lipids, thereby increasing their survival for months on arid surfaces [14]. The elevated prevalence of S. aureus might be due to its resistance to the dry conditions of the hospital environment and transmission from the skin, nostrils, and boils of healthcare workers and patients [11]. Our report is following results from Algeria, Southwest Ethiopia, and Morocco [14-16]. However, Firesbhat et al. in Northwest Ethiopia and Barma and co-investigators in Nigeria found CoNS to be the most dominant bacterial contaminant on beds and door handles in wards [13,25]. Additionally, Ebongue et al., at a reference hospital in Douala, Cameroon, interestingly found E. cloacae as the predominant bacterial pathogen [27]. This variation could be due to differences in the hygienic conditions of study participants, the ventilation system, the frequency of surface decontamination, and the disinfection technique.

We most frequently detected S. aureus 17 (42.5%) from beds of hospital wards, and this finding is consistent with reports from Algeria, Southwest Ethiopia, Addis Ababa in Ethiopia, Southern Ethiopia, and Morocco [11,14-16,28]. Conversely, our evidence does not tie in with studies conducted in Northwest Ethiopia, Hawassa University Comprehensive Specialized Hospital of Ethiopia, a Douala reference hospital in Cameroon, and the University of Maiduguri Teaching Hospital in Nigeria [13,17,25,27]. C. perfringens 7 (35%) was the most dominant bacterial contaminant on door handles in this study. However, contradictory results have been reported by studies carried out in Nigeria, Cameroon, Northwest Ethiopia, Algeria, Southwest Ethiopia, Southern Ethiopia, and Morocco [11,13-16,25,27]. Moreover, the disparity in results could be due to undercooking of food, wrong food storage, and poor hygienic practices (before and after every toilet visit) of health personnel and patients in this study.

The majority of the isolates of S. aureus in our study was susceptible to gentamycin 20 (95.2%) and azithromycin 20 (95.2%), followed by ampicillin 9 (42.9%), and chloramphenicol 8 (38.1%). On the other hand, Worku et al. in Southwest Ethiopia discovered that 11 (57.8%) of S. aureus was sensitive to ciprofloxacin, 6 (31.6%) to gentamycin, 5 (26.3%) to cefoxitin, and 5 (26.3%) to amoxicillin [15]. Also, Firesbhat et al. study in Northwest Ethiopia showed that ciprofloxacin was the most active (9 (60%)) agent against S. aureus, followed by cotrimoxazole 8 (53.3%) and gentamycin 8 (53.3%) [13]. Sebre et al. at the Tikur Anbessa Specialized Teaching Hospital in Addis Ababa, Ethiopia, reported S. aureus sensitivity rates of 55 (88.7%), 53 (84.1%), and 51 (81%) for clindamycin, gentamycin, and ciprofloxacin, respectively [28]. This difference in antimicrobial susceptibility among bacteria might be due to different general mechanisms of resistance, notably the study setting.

C. perfringes were most sensitive to gentamycin 6 (75%) and chloramphenicol 6 (75%). Gentamycin creates fissures in the outer membranes of gram-negative aerobic bacteria, leading to cell leakage and energy-mediated gentamycin uptake [29]. Therefore, gentamycin is less active against gram-positive anaerobes, including C. perfringes. Nevertheless, gentamycin was highly active against C. perfringes in this investigation. This may be because of the enhanced sensitivity (collateral sensitivity) of C. perfringes to gentamycin due to mutations causing multidrug resistance in C. perfringes [30]. Our research is nearly in agreement with an Iranian study performed among patients and healthy individuals at the Imam Reza Educational and Medical Center, which found that ceftriaxone 77 (97.46%) and chloramphenicol 75 (94.93%) were the most active antimicrobials against C. perfringes isolated from stool samples of diarrhea and non-diarrhea patients [31]. Our result is also nearly similar to another study conducted in South Africa, which showed that C. perfringes isolated from patients with suspected mixed aerobic/anaerobic infections were highly sensitive to chloramphenicol (100%), ertapenem (97.2%), and piperacillin-tazobactam (99.4%) [32]. Camacho et al. in Costa Rica reported a corroborating finding that demonstrated that cefotaxime, chloramphenicol, and imipenem were highly active agents against C. perfringes isolated from fecal samples of patients diagnosed with antibiotic-associated diarrhea [33].

Studies conducted in France, Southeastern Hungary, and Iraq have revealed contrary antibiotic sensitivity rates: (tigecyclin 86.5% and clindamycin 59.5%), (amoxicillin/clavulanic acid 100%, cefoxitin 100%, meropenem 100%, imipenem 100%, and metronidazole 100%), and (penicllins and β-lactamase inhibitors, metronidazole, and aminoglycosides), respectively, of C. perfringes isolated from wounds of patients or fecal samples of neonates [34-36]. These discrepancies in antibiotic-sensitivity profiles might be attributed to inappropriate administration of antimicrobials or variations in hospital environmental conditions, self-medication practices, and personal hygiene.

To our knowledge, this is the first study that has reported C. perfringes and Clostridium spp. from beds and door handles in hospital wards. Secondly, we found that C. perfringes is the most dominant bacterial pathogen on ward door handles. Thirdly, gentamycin was identified as an active agent against C. perfringes, in addition to chloramphenicol, which is an already-established antibiotic against C. perfringes. Lastly, C. perfringes was resistant to cephalothin.

Study limitations: the number of hospitals included in this study was small, which led to a limited sample size. Moreover, only seven different antibiotic discs were used to determine the antibiotic susceptibility of bacterial isolates. Therefore, the generalizability of our findings may be affected. Furthermore, Clostridium spp. other than C. perfringes could not be isolated in this study because of limited laboratory resources for laboratory analysis.

Conclusion     

S. aureus and Bacillus spp. had the highest contamination rates on beds and door handles in hospital wards. C. perfringes is the most common bacterial contaminant on door handles, while S. aureus is most commonly isolated from patient beds. S. aureus, K. pneumoniae, Bacillus spp., and Clostridium spp. showed the highest sensitivity to gentamycin. These isolates, except K. pneumoniae, were multi-drug resistant and most resistant to bacitracin. Food safety measures should be strictly followed in hospitals to prevent or manage outbreaks of foodborne diseases. Hospital beds and door handles should be regularly and adequately disinfected and cleaned. Hand hygiene should be routinely practiced by patients and healthcare workers through hand washing or the provision and use of hand sanitizers.

Competing interests     

The authors declare no competing interests.

Authors' contributions     

Njeodo Njongang Vigny: writing-original draft (lead); formal analysis (lead); writing-review and editing (equal). Binwie Fanuella Shu: conceptualization (lead); writing-review and editing (equal). All the authors have read and approved the manuscript for submission.

Acknowledgments     

The authors appreciate the contributions made by the Chief Medical Officer and laboratory staff at Regina Pacis Hospital, Private Medical Insurance (PMI) Hospital, COMWEL Clinic, and Tiko District Hospital. We are also grateful for the collaboration of ward heads in these hospitals.

Table and figures     

Table 1: antimicrobial susceptibility pattern of bacteria isolated from hospital ward beds and door handles in the Tiko health district

Figure 1: frequencies of bacterial isolates from beds and door handles of hospital wards in Tiko health district

Figure 2: frequencies of bacterial isolates from hospitals based on ward surface

Figure 3: frequencies of bacterial isolates from wards´ beds and door handles based on hospital

References