Prevalence of Staphylococcus Species from Clinical Samples Obtained from Some Hospitals on Kano Metropolis, Nigeria

The study was aimed to determine prevalence of Staphylococcus species among patients attending some hospitals in Kano, Northern Nigeria. Three hundred (300) samples from ear swab, high vaginal swab (HVS), wound swab and urine were collected from patients (133 males and 167 females) attending the Hospitals over a period of eight months (October, 2016 to May, 2017). The samples collected inoculated onto the surface of freshly prepared Nutrient agar for colony formation and isolation. Each colony was isolated in a pure form by sub culturing for further studies and identification. The result showed that the distribution of Staphylococcus aureus and other Coagulase Negative Staphylococcus in the clinical samples for the three hospitals, S. aureus was isolated most from wound swab with 51 isolates (33.33%) followed by ear swab with 46 isolates (30.07%) and then H.V.S and urine with 28 isolates accounted for (18.30%) each. CoNS was isolated most from urine sample with 11 isolates (36.67%) followed by H.V.S with 9 isolates (30.00%) then ear swab with 8 isolates (29.51) and wound swab, 2 isolates accounted for (6.67%). Statistical analysis of the result showed significant difference in the prevalence of Staphylococcus species among the samples examined at p<0.05. Staphylococci are one of the etiologic agents of infectious diseases.


Introduction
Staphylococci are frequently isolated as etiologic agents of infectious processes, with Staphylococcus aureus being the most important human pathogen. S. aureus causes superficial and deep skin and soft tissue infections, bacteremia with metastatic Staphylococci are frequently isolated as etiologic agents of infectious processes, with Staphylococcus aureus being the abscess formation, and a variety of toxin-mediated diseases, including gastroenteritis, staphylococcal scalded skin syndrome, and toxic shock syndrome [1]. S. aureus has long been recognized as one of the most important bacteria that cause disease in humans. It is the leading cause of skin and soft tissue infections such as abscesses (boils), furuncles and cellulitis. Although most Staphylococcal infections are not serious, S. aureus can cause serious infections such as blood stream infections, pneumonia, or bone and joint infections [2]. S. aureus can also cause serious infections such as pneumonia (infection of the lungs) or bacteremia (bloodstream infection), symptoms of these infections include: difficulty breathing, malaise, fever or chills [2].
In addition, two coagulase-negative staphylococcal species, S. epidermidis and S. saprophyticus, are also recognized as important agents of human infections. S. epidermidis is associated with infections of indwelling devices, osteomyelitis, wound infections, peritoneal dialysis catheter-associated peritonitis, and nosocomial bacteremia [3]. S. saprophyticus is recognized primarily as a cause of acute urinary tract infections in young women [4]. Together, these two coagulase-negative species comprise the greater majority of the clinically significant coagulase-negative staphylococci recovered from human specimens [5]. Staphylococcus epidermidis is isolated prevalently from human epithelia and colonizes predominantly the axillae, head, and nares [6]. S. epidermidis belongs to the group of coagulase-negative staphylococci (CoNS), which is discriminated from coagulase-positive Staphylococci, such as S. aureus by its lack of the enzyme coagulase [7]. Indeed, this pathogen is part of represents the most frequent causative agent involved with infections involving any kind of medical devices, such as peripheral or central intravenous catheters [8]. Specifically, catheter-related infections are associated with increased mortality and contribute to an increased length of hospital stay and higher healthcare costs, which are problematic in limited-resource settings [9].
Staphylococcus saprophyticus is uniquely associated with un-complicated urinary tract infection (UTI) in humans. It has special urotropic and ecologic features that are distinctly different from other staphylococci and from Escherichia coli. This article will consider the epidemiology, ecology, pathogenesis, and clinical features of infections caused by this microorganism. Much more needs to be learned about the epidemiology and natural history of UTI caused by S. saprophyticus as well as the role of S. saprophyticus in human and animal health and disease. A series of research questions are offered to address these issues. Coagulase-negative staphylococci were considered to be urinary contaminants prior to the 1960s. In 1962, Torres Pereira [10] reported the isolation of coagulase-negative staphylococci possessing antigen 51 from the urine of women with acute UTI. In subsequent years, additional reports supported this concept [11]. The laboratory identification of S. aureus has traditionally depended on the demonstration of coagulase production by the tube coagulase test [12]. Susceptibility to novobiocin is a factor widely used in clinical laboratories for the presumptive identification of S. saprophyticus [13]. The study was aimed to determine prevalence of Staphylococcus species among patients attending some hospitals in Kano, Northern Nigeria.

Study Area
The research was conducted in Kano central area which lies between Latitude 11.90 North and Longitude 8.50 East in North western Nigeria, Kano state occupies 20,131 square kilometers and is bounded to the North west by Katsina State, North east by Jigawa State to the north east and south by Bauchi and Kaduna. The area is densely populated comprising of 9,383,682 [14].

Sample Size
A total of 300 samples were collected, a standard epidemiological formula (Fisher's formula) was used to calculate the sample size.
The prevalence and antimicrobial susceptibility of MRSA and CoNS isolated from healthy students in Ota, Nigeria as reported by Joshua and Ronke [15] was 78% this was scaled to 300 at 95% confidence interval, and the sample size was calculated using a formula by Therefore, a total of 263.7 with 14% (36.8) of this subject will be added to the research for attrition, making a total of approximately 300 samples was involved in the study.

Statistical Analysis
The data generated were subjected to descriptive statistical analysis using percentages and Chi -square analysis was used in

Am J Biomed Sci & Res
Copy@ Muhammad Ali determining the prevalence rates. p<0.05 was considered indicative of a statistically significant difference.

Age Distribution of the Patients
The     Table 4 described the distribution of Staphylococcus aureus and other Coagulase Negative Staphylococcus in the clinical samples for the three hospitals, S. aureus was isolated most from wound swab with 51 isolates (33.33%) followed by ear swab with 46 isolates (30.07%) and then H.V.S and urine with 28 isolates accounted for (18.30%) each. CoNS was isolated most from urine sample with 11 isolates (36.67%) followed by H.V.S with 9 isolates (30.00%) then ear swab with 8 isolates (29.51) and wound swab, 2 isolates accounted for (6.67%) ( Table 4). The non-coagulase Staphylococci identified amongst these samples might have been contaminants or opportunistic pathogens; which is in consistent with the report titled isolation of coagulasenegative Staphylococci and catalase negative organism in the urine of high school children in Abakaliki. It is well known that other Staphylococci though normal commensals are opportunistic pathogen of man [20].

Conclusion
The study has demonstrated the occurrence of S. aureus and