Received Date: October 01, 2015; Accepted Date: October 26, 2015; Published Date: November 02, 2015
Citation: Onaolapo JA, Afolabi OE, Igwe JC (2015) Incidence and Antibiotic Susceptibility Profile of Staphylococcus aureus on Door Handles in Ahmadu Bello University, Zaria. J Trop Dis 4:184. doi:10.4172/2329-891X.1000184
Copyright: © 2015 Onaolapo JA,et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Visit for more related articles at Journal of Tropical Diseases & Public Health
Pathogenic microorganisms implicated in most diseases are transferable through contact with infected persons or objects. In this study, door handles in the Faculty of Pharmaceutical Sciences and Amina female hostel in Ahmadu Bello University, Zaria, Nigeria were evaluated for the presence of Staphylococcus aureus and their antibiotics susceptibility profile was tested, using standard microbiological methods. The results showed that out of the 143 door handles sampled (Amina female hostel = 89, Pharmacy main block = 40, Pharmacy old block = 14), the incidence of Staphylococcus aureus was 50.7%(34) [with highest occurrence in Amina female hostel (35.8%), followed by Pharmacy main block (8.9%) and Pharmacy old block (6.0%)], E. coli was observed to be the second most common organism (9%) followed by Shigella dysentery 7.5%, while Salmonella typhi, Seretia spp. and Pseudomonas aeruginosa were both 6% respectively. The antibiotic susceptibility profile of the isolates showed that they were 100% susceptible to Ciprofloxacin, Erythromycin and Tetracycline, 97% susceptible to Mupirocin, and Cotrimoxazole, and 92% to Pefloxacin and Oxacillin. Their levels of resistance to these antibiotics were very low (3% resistance to Mupirocin and Cotrimoxazole, 8% to Pefloxacin and Oxacillin), while their resistances to Amoxicillin, Cefuroxin sodium and Cefotaxime were very high (100%). An evaluation of the pattern of resistance of the isolates showed that 76.5% of the isolates had MAR index of ≤0.4 while 70.6% of the isolates were multidrug resistant; exhibiting resistance to some commonly used Fluoroquinolone, Cephalosporine (CEP), and Betalactam/Betalactamase inhibitors (BET) groups of antibiotics (73.5%). The high incidence of Staphylococcus aureus in this study suggests poor hygiene among students, and the possibility of transferring pathogenic Staphylococcus aureus through door handles in a densely populated environ during disease outbreak is probable. To curb the spread of pathogenic and resistant Staph. aureus, this study suggests that door handles in A.B.U, Zaria should be replaced with silver coated surfaces with antimicrobial properties, and frequent use of disinfectant/hand sanitizer is recommended. Also proper periodic antibiotic surveillance should be encouraged to have referable documentaries in disease outbreak.
Staphylococcus aureus; Door handles; Antibiotic susceptibility profile; Hygiene
Environmental contamination with pathogenic microorganisms which are of clinical importance due to their contribution to morbidity and mortality is increasing daily. Such microorganisms especially skin associated ones like Staphylococcus aureus have been isolated from various sites or surfaces touched by hands both in hospitals and nonhospital environments e.g. bed sheets, bed crank, tables, buttons on the infusion pump, cotton gowns, sink handles, toilet flushes, toilet seats, cell bars, light switches, soap dishes, window handles, locker handles, radios, door handle, boxing gloves, basketballs, abdominal crunch machine, seated and upright leg presses in gymnasium and hand sanitizer dispenser [1-3]. The possibilities of isolating Staphylococcus aureus from these environments might be as a result of their extreme flexibility and capacity for rapid growth and reproduction . This wide spread of Staphylococcus aureus contributes to its importance as a nosocomial and community-acquired pathogen, whose genetic plasticity could facilitate the evolution of many virulent and antibiotics resistant strains, which could present a major and constantly changing clinical problems . Staphylococcus aureus has been implicated in diseases such as dermatitis, pneumonia, septicaemia, osteomyelitis and meningitis in both humans and swine, as well as bovine mastitis in cattle and bumblefoot disease in poultry . Studies have demonstrated that, even with high compliance to hand hygiene measures, cross-transmission of Staphylococcus aureus could still occur, but how beneficial or harmful Staphylococcus aureus as environmental contaminate could depend greatly on human measure or observation [7,8]. As microbial resistance to antibiotic commonly prescribed is becoming a global challenge, this study evaluates the antibiotics susceptibility profile of Staphylococcus aureus isolated from door handles in the Faculty of Pharmaceutical Sciences and Amina female hostels in Ahmadu Bello University, Zaria, Nigeria in order to quantify the level of antibiotics resistance and to proffer better treatment or management options to infections associated with Staphylococcus aureus contacted from door handles in this area.
A total of one hundred and forty three (143) samples from door handles were randomly collected using sterile swab sticks containing sterile normal saline. The samples were aseptically collected from Amina female hostel, Pharmacy main block and Pharmacy old block of Ahmadu Bello University Zaria, Samaru Campus (A.B.U).
Microbial identification, isolation and microscopy
Collected samples were suspended in sterile nutrient broth for 24hrs and then inoculated on the surface of sterile nutrient agar (NA), and incubated at 37°C for 18hrs. Gram staining and microscopy were also carried out to differentiate between Gram positive and Gram negative organisms using the method described by Chakraborty and Nishith,  while further morphological characterization of the colonies were carried out on Mannitol salt agar using the method described by Cheesbrough . The presence of other microbial growth on MacConkey agar, Eosin methylene blue agar and Cetrimide agar were also observed.
The following conventional biochemical tests; catalase, coagulase and oxidase tests described by Cheesbrough  were adopted to distinguish Staphylococcus aureus from other forms of Staphylococcus spp. While the Gram negatives organisms were identified by their colour on indole, methyl red, Vogue Prosker, citrate and urease described by Chakraborty and Nishith .
Antibiotic susceptibility test and multiple antibiotic resistance index (MARI) evaluation
The susceptibility profiles of the identified Staphylococcus aureus was tested against twelve (12) selected antibiotics (Tetracycline (TE), Cefuroxin sodium (CXM), Cefotaxime (CTX), Mupirocin (MUP), Ciprofloxacin (CIP), Ofloxacin (OFX), Perfloxacin (PEF), Oxacillin (OX), Cotrimoxazole (SXT), Erythromycin (E), Amoxicillin/ clavulanic acid (AMC), Amoxicillin (AML)) using disc diffusion method as described by Cheesbrough  and the corresponding results interpreted using CLSI . The multiple antibiotic resistant (MAR) index was determined for each isolate. This is defined as the number of antibiotics to which the organism is resistant to, divided by the total number of antibiotics tested .
Out of the 143 door handles sampled, the incidence of Staphylococcus aureus was 23.8% (34) with highest occurrence in Amina female hostel (16.8%), followed by Pharmacy main block (4.2%) and Pharmacy old block (2.8%) as shown in Table 1. Among the samples collected, culture identification, microscopy and biochemical tests also showed the presences of other microorganisms. The incidence of E. coli (9%) and Shigella dysentery (7.5%) were found to be the most common bacteria compared to other microorganisms isolated after Staphylococcus aureus. This is shown in Table 2.
|S/N||Sample Source||No. Of Door Handles Sampled||Number of Staph. aureus||Percentage of Staph. aureus(%)|
|1||Amina female hostel||89||24||35.8|
|2||Pharmacy main block||40||6||8.9|
|3||Pharmacy old block||14||4||6.0|
Table 1: Distribution of Staph. aureus In Door Handles in Ahmadu Bello University, Zaria.
|S/N||ORGANISMS||Number of Isolates (n = 67)||Percentage (%)|
|10||Salmonella paratyphi A||2||3|
This result showed the microbial contaminate on door handles in the areas sampled
Table 2: Percentage of Bacteria Isolated from the Door Handles Sampled.
Antibiotics susceptibility profile of Staphylococcus aureus from the sampled area
The isolates were highly susceptible to Erythromycin, Ciprofloxacin, and Tetracycline (100%), 97% susceptible to mupirocine and cotrimoxazole, 90% to Pefloxacine, and 85% to Oxacillin. But the isolates were observed to be 100% (34) resistant to Cefotaxime and Amoxicillin, 96.7% (33) resistant to Cefuroxin sodium, 76.6% and 70 % resistant to Ofloxacine and Amoxicillin clavulanic acid respectively (Figure 1).
The dissemination of clinically significant microorganism within our environment is fast growing through cross contamination of the surfaces due to poor hygiene. Reports have pinpointed doors handle, computer surfaces, phones etc as sources of microbial transfer and could also be a route of infections in diseases outbreak [13,14]. This study evaluates the incidence and antibiotics susceptibility profile of Staphylococcus aureus from door handles in the Faculty of Pharmaceutical Sciences and Amina female hostels in Ahmadu Bello University, Zaria. Out of the 143 door handles sampled, the incidence of Staphylococcus aureus was 50.7% (34) with highest occurrence in Amina female hostel (35.8%), followed by Pharmacy main block (8.9%) and Pharmacy old block (6.0%) (Table 1).The result showed that a total of eleven (11) different microorganisms were isolated. Staphylococcus aureus was observed to be present in all the samples evaluated (50.7) (Table 3) followed by E. coli (9%), Shigella dysentery (7.5%), Salmonella typhi, P. aeruginosa, and Seretia spp. (6%), Klebsiella spp. (4.4%), Citrobacter spp., Proteus mirabilis and Salmonella paratyhi A (3%) and Enterobacter spp. (1.4%) (Table 3). These findings concurred with the report of Ajayi and Ekozien  in Ekpoma, Kawo et al.,  in Kano and Itah and Ben  in Akwa Ibom, Nigeria, who reported that Staphylococcus aureus and E. coli are the most predominate surface microbe from door handles, tables, hand of students and computers. These surfaces especially the door handle are indeed a breeding ground for microbes as reported by Barker and Jones , who noted that contamination of the environment via the surface-to-hand-to-mouth could be an avenue of contacting diseases and encourages disease wide spread. This calls for good hygienic practices as these microbes are signal of unhygienic environment . The antibiotic susceptibility profile of the Staphylococcus aureus isolated from the sampled door handles showed that the isolates were highly resistant (100% (34)) to Cefotaxime and Amoxicillin, 96.7% (33) resistance to Cefuroxin sodium, 76.6% and 70% resistance to Ofloxacine and Amoxicillin clavulanic acid respectively (Figure 1). This result concurs with other studies that Staphylococcus aureus from surfaces have high percentages of antibiotic resistance even to methicillin (60.4%) ; Gentamicin, Amoxicillin-clavulanic acid and Cotrimoxazole . This suggests that in situation of such infections from door handle, these antibiotics should not be hoped on as the last resort for treatment. However, promising for therapeutics are Erythromycin, Ciprofloxacin, and Tetracycline as the isolates from this study showed 100%, 97% susceptibility to Mupirocine and Cotrimoxazole respectively, 90% to Pefloxacine, and 85% to Oxacillin. This result is supported by the study of Ajayi and Ekozien, . Also in the areas sampled the antibiotic susceptibility pattern of the isolated Staphylococcus aureus showed that 96.7% of the isolates were simultaneously resistant to Amoxicillin, Cefuroxin sodium (CXM) and Cefotaxime (CTX); while 73.5% were resistant to Fluoroquinolone, Cephalosporine (CEP), and Betalactam/Betalactamase inhibitors (BET) groups of antibiotics. The result also showed that 76.5% of the isolates had MAR index of ≤0.4 while 70.6% of the isolates were multidrug resistant (Table 4). The high resistance observed in this study concur with the observation of Daniel and Kenneth , in whose study 50% (6) of the total antibiotics tested (12) (Ampicillin, Penicillin, Cefuroxime and Cloxacillin, and Amikacin) were inactive against both Gram-positive and Gram-negative bacteria isolated. Pattern of isolates antibiotics resistance was classified according to Magiorakos et al., . The high multiple antibiotic resistance observed in this study also concur with the observation of Oluduro et al., , who observed that the isolates from door handles had 89.1% MDR, with a total of 68 resistance patterns and resistance to three antibiotics simultaneously were the most frequent (31.9%). This finding showed that the isolates might have been pre-exposed to the antibiotics used in this study and emphasized the need for antibiotic surveillance in order to curtail the development of resistance.
|S/no||Isolates||Gram Positive||Mannitol||Catalase||Coagulase||Oxidase||Probable organism|
|1||A2a||+||Golden yellow||+||+||_||Staph. aureus|
|2||A2b||+||Golden yellow||+||+||_||Staph. aureus|
|3||B1a||+||Golden yellow||+||+||_||Staph. aureus|
|4||D1b||+||Golden yellow||+||+||_||Staph. aureus|
|5||D2b||+||Golden yellow||+||+||_||Staph. aureus|
|6||E2a||+||Golden yellow||+||+||_||Staph. aureus|
|7||F1a||+||Golden yellow||+||+||_||Staph. aureus|
|8||F1b||+||Golden yellow||+||+||_||Staph. aureus|
|9||F2a||+||Golden yellow||+||+||_||Staph. aureus|
|10||F2b||+||Golden yellow||+||+||_||Staph. aureus|
|11||G2a||+||Golden yellow||+||+||_||Staph. aureus|
|12||H1a||+||Golden yellow||+||+||_||Staph. aureus|
|13||H1b||+||Golden yellow||+||+||_||Staph. aureus|
|14||H1c||+||Golden yellow||+||+||_||Staph. aureus|
|15||H2a||+||Golden yellow||+||+||_||Staph. aureus|
|16||H2b||+||Golden yellow||+||+||_||Staph. aureus|
|17||H2c||+||Golden yellow||+||+||_||Staph. aureus|
|18||I1a||+||Golden yellow||+||+||_||Staph. aureus|
|19||I1b||+||Golden yellow||+||+||_||Staph. aureus|
|20||I2||+||Golden yellow||+||+||_||Staph. aureus|
|21||J2a||+||Golden yellow||+||+||_||Staph. aureus|
|22||K1a||+||Golden yellow||+||+||_||Staph. aureus|
|23||K2b||+||Golden yellow||+||+||_||Staph. aureus|
|24||L1a||+||Golden yellow||+||+||_||Staph. aureus|
|25||L1b||+||Golden yellow||+||+||_||Staph. aureus|
|26||M1a||+||Golden yellow||+||+||_||Staph. aureus|
|27||M1b||+||Golden yellow||+||+||_||Staph. aureus|
|28||N2a||+||Golden yellow||+||+||_||Staph. aureus|
|29||N2b||+||Golden yellow||+||+||_||Staph. aureus|
|30||D2c||+||Golden yellow||+||+||_||Staph. aureus|
|31||M2p||+||Golden yellow||+||+||_||Staph. aureus|
|32||N2c||+||Golden yellow||+||+||_||Staph. aureus|
|33||N2g||+||Golden yellow||+||+||_||Staph. aureus|
|34||D2h||+||Golden yellow||+||+||_||Staph. aureus|
Table 3: Isolation and Characterization of Staphylococcus aureus from Door handles in A.B.U.
|S/N||ISOLATES||Antibiotics Resistant Pattern||MARI||CART||DR|
|1||F1a||CTX, CXM, AML||0.3||CEP, BET||XDR|
|2||D2b||CTX, CXM, AML, OFX||0.3||CEP, BET||XDR|
|3||I1b||AMC, CTX, CXM, AML, PEF, OFX||0.5||CEP, BET, FLU||MDR|
|4||H1b||AMC, CTX, CXM, AML, OFX||0.4||CEP, BET, FLU||MDR|
|5||H2c||AMC, CTX, CXM, AML, OX, OFX||0.5||CEP, BET, FLU||MDR|
|6||K2b||CTX, CXM, AML,||0.3||CEP, BET||XDR|
|7||I2||CTX, CXM, AML, OFX||0.3||CEP, BET, FLU||MDR|
|8||L1a||AMC, CTX, CXM, AML, OFX||0.4||CEP, BET, FLU||MDR|
|9||F1b||AMC, CTX, CXM, AML, OFX||0.4||BET, CEP, FLU||XDR|
|10||E2a||AMC, CTX, CXM, AML, PEF, OFX||0.5||BET, CEP, FLU||MDR|
|11||F2b||AMC, CTX, CXM, AML, OFX||0.4||BET, CEP, FLU||MDR|
|12||D2c||AMC, CTX, CXM, PEF, AML, OFX||0.5||BET, CEP, FLU||MDR|
|13||A2b||AMC, CTX, CXM, AML,||0.3||BET, CEP||XDR|
|14||A2a||AMC, CTX, CXM, AML||0.3||BET, CEP||XDR|
|15||H1a||CTX, OX, OFX, AML,||0.3||CEP, BET, FLU||MDR|
|16||I1a||CTX, CXM, AML, OFX||0.3||BET, CEP, FLU||MDR|
|17||H1c||CTX, CXM, OFX, AML,||0.3||CEP, BET, FLU||MDR|
|18||G2a||AMC, CTX, CXM, AML, OFX||0.4||BET, CEP, FLU||MDR|
|19||H2b||CTX, CXM, AML, OFX||0.3||BET, CEP, FLU||MDR|
|20||B1a||AMC, CTX, CXM, OFX, MUP, AML||0.5||BET, CEP, FLU, PS||MDR|
|21||J2||CTX, CXM, AML,||0.3||CEP, BET||XDR|
|22||F2a||AMC, CTX, CXM, OFX, AML,||0.4||BET, CEP, FLU||MDR|
|23||D1b||CTX, CXM, AML, OFX||0.3||CEP, BET FLU||MDR|
|24||K1b||AMC, CTX, CXM, AML, OFX||0.4||BET, CEP, FLU||MDR|
|25||L1b||AMC, CTX, CXM, AML||0.3||BET, CEP||XDR|
|26||M1a||AMC, CTX, CXM, AML, OX, OFX||0.5||BET, CEP, FLU||MDR|
|27||M1b||AMC, CTX, CXM, AML, OFX||0.4||BET, CEP, FLU||MDR|
|28||N2a||AMC, CTX, CXM, AML, OFX||0.4||BET, CEP, FLU||MDR|
|29||N2b||AMC, CTX, CXM, AML, OFX||0.5||BET, CEP, FLU||MDR|
|30||H2a||AMC, CTX, CXM, AML,||0.3||BET, CEP||XDR|
|31||M2p||AMC, CTX, CXM, AML,||0.3||BET, CEP||XDR|
|32||N2c||AMC, CTX, CXM, AML, SXT, OFX||0.5||BET, CEP, FLU, FPI||MDR|
|33||N2g||AMC, CTX, CXM, AML, OFX||0.4||BET, CEP, FLU||MDR|
|34||D2h||AMC, CTX, CXM, AML, OFX||0.4||BET, CEP, FLU||MDR|
Keys: Tetracycline (TE), Cefuroxin sodium (CXM), Cefotaxime (CTX), Mupirocin (MUP), Ciprofloxacin (CIP), Ofloxacin (OFX), Perfloxacin (PEF), Oxacillin (OX), Erythromycin (E), Amoxicillin/clavulanic acid (AMC), Amoxicillin (AML). Class of antibiotics resistant to (CART), Degree of resistance (DR), Betalactam/Betalactamase inhibitors (BET), Folate pathway inhibitors (FPI), Cephalosporine (CEP), Fluoroquinolone (FLU), Macrolide (MAC), Pseudomonic acid (PS), MDR: Multidrug-resistant, XDR: Extensively drug-resistant NIL: neither MDR nor XDR. MDR: non-susceptible to ≥1 agent in ≥3 antimicrobial categories. XDR: non-susceptible to ≥1 agent in all but ≥2 categories. PDR: non-susceptible to all antimicrobial agents listed. PDR was not considered because not all the antibiotics contained in the proposal of Magiorakos et al., (2012) are used in this study.
Table 4: Evaluation of the Antibiotic Resistance Pattern and Index (MARI) of Staph. aureus.
This study on Staphylococcus aureus from door handles in A.B.U Zaria have proved that door handles serve as reservoir and route of microbial dissemination in disease outbreak. It also suggests the use of ciprofloxacin, erythromycin, tetracycline, mupirocin and oxacilline as the best antibiotics during infection associated with door Staphylococcus aureus. It also encourages the need to promote proper hygienic practice and adherence to antibiotic treatment in order to prevent the spread of resistance bacteria. For immediate action, this study suggests the use of silver coated door handles with antimicrobial activity in other to reduce the microbial load from this source, and frequent use of disinfectant/ hand sanitizer is recommended. Also proper periodic antibiotic surveillance should be encouraged to have referable documentaries in disease outbreak.