Sensitivity and antibiogram types of staphylococcus species isolated from uropathogenic infections

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1 Open Science Journal of Clinical Medicine 2014; 2(3): Published online June 10, 2014 ( Sensitivity and antibiogram types of staphylococcus species isolated from uropathogenic infections Orhue P. O. 1, *, Momoh A. R. M. 2, Igumbor E. O. 1, Esumeh F. I. 1 1 Department of Microbiology, Faculty of Natural Sciences; Ambrose Alli University, Ekpoma-Nigeria 2 Department of Medical Microbiology, Faculty of Clinical Sciences, College of Medicine; Ambrose Alli University, Ekpoma-Nigeria address orhue_philips@yahoo.com (Orhue P. O.) To cite this article Orhue P. O., Momoh A. R. M., Igumbor E. O., Esumeh F. I.. Sensitivity and Antibiogram Types of Staphylococcus Species Isolated from Uropathogenic Infections. Open Science Journal of Clinical Medicine. Vol. 2, No. 3, 2014, pp Abstract Bacteria are capable of invading and infecting humans, leading to disease and sometimes death. Specifically, Staphylococcus bacteria are known to be a common cause of infections with high prevalence worldwide. In this study, the antibiogram types of three strains of staphylococcus bacteria were investigated. The study involves 407 urine samples collected from in and out patients with suspected cases of urinary tract infections attending the University of Benin Teaching Hospital (UBTH), Benin, Edo State, Nigeria. Overall, the prevalent of staphylococcus infections was 18.67% distributed as staphylococcus aureus (36; 47.37%), Streptococcus faecalis (29; 38.16%) and staphylococcus saprophyticus (11; 14.47%). The Ajumali s mnemonic coding showed that no two strains of any of the staphylococcus spp were the same and by implication indicating a high resolving power. However, the 18.67% burden of staphylococcus spp as a cause of UTI requires consideration. Keywords Urinary Tract Infections, Staphylococcus Species, Antibiogram Types, Ajumali s Mnemonic Coding 1. Introduction Urinary tract infections (UTIs) are infections caused by the presence and growth of one or more microorganism(s) anywhere in the urinary tract or system ([1]). They are among the most common bacterial infections in humans both in the community and hospital settings ([2]). On the other hand, Staphylococcal infections are said to occur regularly in hospitalized patients and have severe consequences, despite antibiotic therapy ([3], [4]). In fact, Staphylococcus aureus can be a human commensal or a potentially lethal opportunistic pathogen as it is among the leading causes of a variety of community-acquired and hospital acquired bacterial infections. S. aureus is one of the most common causes of bacteraemia, and carries a higher mortality than any other 65-70% in the preantibiotic era, and currently 20-40% mortality at thirty days despite appropriate treatment ([5], [6]). Worrisome, due to an increasing number of infections caused by methicillin-resistant S. aureus (MRSA) strains, which are now most often multi-resistant, therapy has become problematic ([7]). Therefore, prevention of staphylococcal infections is now more important than ever. Moreover, drug resistance among bacteria causing UTI has increased since introduction to UTI chemotherapy ([8], [9], [10], [11], [12]). The etiological agents and their susceptibility patterns of UTI vary in regions and geographical location. Besides, the etiology and drug resistance change through time ([13]) Knowledge of the local bacterial etiology and susceptibility patterns is required to trace any change that might have occurred in time so that updated recommendation for optimal empirical therapy of UTI can be made ([14]). In Ethiopia, a number of studies have been done on the prevalence and antimicrobial resistance patterns of UTIs ([8], [15], [16]). The aim of the present study was therefore to determine the prevalence of

2 78 Orhue P. O. et al.: Sensitivity and Antibiogram Types of Staphylococcus Species Isolated from Uropathogenic Infections Staphylococcus bacteria, their susceptibility to commonly used antimicrobials and antibiogram types using Ajumali s mnemonic coding, from in and out patients with suspected cases of urinary tract infections attending the University of Benin Teaching Hospital (UBTH), Benin, Edo State, Nigeria. 2. Materials and Methods 2.1 Specimen: A total of 407 clinical specimen comprising of Mid-Stream urine (MSU), Super-public urine (SPU) and catheter specimen were collected from in-and out patients in UBTH, between July, 2009 and December, 2009 for this study ([17]). These samples were taken to the laboratory for standard microbiological analysis with 30 minutes of collection. 2.2 Isolation and identification: The specimen was inoculated onto nutrient agar, blood agar and MacConkey agar plates by streaking. Inoculated plates were then incubated aerobically at 37oC for 24 hours. After 24 hours of incubation, discrete colonies were picked up and Gram stained and further sub-culturing was done to obtain pure cultures and biochemical tests were carried out Antibiotics under Study ([18]) 1. Ciprofloxacin: This drug is a fluoroquinolone and acts by inhibiting DNA topoisomerases (gyrases); and thus inhibiting bacterial DNA synthesis. 2. : This drug belongs to the class of macrolide, it is bacteriostatic, binding to the 23-RNA of the 50s ribosomal subunit to inhibit peptide chain elongation during protein synthesis. 3. Augmentin: This is a combination of amoxycillin and clavulinic acid. The clavulinic acid helps protect the amoxycillin from being inactivated by the enzyme beta-lactamsae, an enzyme produced by pathogenic bacteria. 4. Gentamycin: This drug is an aminoglycoside which binds to small ribosome subunits and interfere with protein synthesis by directly inhibiting protein synthesis. 5. : This is a broad spectum antibiotic of the cephalosporin class. It is an alternate drug of choice when patients are allergic to the penicillins or when there is a need to overcome beta-lactamase inactivation. 2.4 Antibiotics susceptibility testing (Antibiogram): This was done by the multi-discs diffusion using 21 different antibiotics. The multi-discs were placed on the plates which were previously inoculated, few minutes earlier, then the plates were incubated at 37oC for 24 hours, thereafter, the plates were examined for zones of inhibition around the different antibiotic disc. Staphylococcus aureus Oxford strain NTC 6751 was used as control for Gram positive organisms. 2.5 Mnemonic Coding: The Ajumali s mnemonic coding method as earlier described by Joghi et al., ([19]), was adopted as a typing scheme to re-arrange the nominal antibiotics into arbitrary numeric values, making it easy for the differentiation of strains. Using this pneumonic coding scheme, a sensitive result was scored as (+), while a resistance was scored as (-). Also, the 21 different antibiotics were divided into a group of 3 antibiotics each, following their mechanisms of action as well as; their clinical applications; and these 3 antibiotics were given numerical values of 1, 2 and 4 ([17]). Thus, a perfect sensitivity to the 3 antibiotics will give a summation of =7. While complete resistance to the 3 antibiotics will give a summation of = 0. The other values as obtained by adding up these numerical values thus, an isolate can receive a score of 0-7 in each triplet segment, which, when the seven triplet segments are combined together, gives a seven (7) digit numerical value as the antibiogram types ([17]) Data analysis: All data were analyzed using simple descriptive statistic. 3. Results Table 1. Sensitivity and antibiogram types of staphylococcus aureus Out of the 407 samples cultured, 76 were positive for Staphylococcus species resulting in a prevalence of 18.67%. Specifically, Staphylococcus aureus presented the highest percentage of prevalent (36; 47.37%). This was followed by Streptococcus faecalis (29; 38.16%) and then Staphylococcus saprophyticus (11; 14.47%). The antibiotic sensitivity and antibiogram types of the Staphylococcus aureus, Streptococcus faecalis and Staphylococcus saprophyticus are presented in table 1, 2 and 3 respectively. The Ajumali s mnemonic coding showed that no two strains of any of the Staphylococcus spp were the same for the Staphylococcus spp or within the samples in Staphylococcus aureus, Streptococcus faecalis and Staphylococcus saprophyticus. Staphylococcus aureus Antibiogr am Types

3 Open Science Journal of Clinical Medicine 2014; 2(3): Staphylococcus aureus Antibiogr am Types % S % S= percentage sensitivity [%S= isolates sensitive/ total number of isolates] Table 2. Sensitivity and antibiogram types of Streptococcus faecalis Streptococcus faecalis Antibiog ram Types

4 80 Orhue P. O. et al.: Sensitivity and Antibiogram Types of Staphylococcus Species Isolated from Uropathogenic Infections Streptococcus faecalis Antibiog ram Types % S % S= percentage sensitivity [%S= isolates sensitive/ total number of isolates] Table 3. Sensitivity and Antibiogram types of staphylococcus saprophyticus Staphylococcus saprophyticus Bacterial Isolates Antibiogr am Types %S % S= percentage sensitivity [%S= isolates sensitive/ total number of isolates] 4. Discussion The high prevalence of Staphylococcus aureus (36; 47.37%) compared to other isolated Staphylococcus spp. agrees with previous studies ([20], [21]) [3, 15]. This prevalence level may be related to the mode of transmission of S. aureus which occurs almost exclusively as a result of direct skin-to-skin contact, or contact with recently contaminated fomites ([22], [23] Although all the antibiotics used in this study were sensitive to Staphylococcus aureus isolates (see table 1),,,,, etracycline,, and were poorly sensitive as they presented percentage of sensitivity less than 40%. On the other hand, Streptococcus faecalis

5 Open Science Journal of Clinical Medicine 2014; 2(3): isolates were not sensitive to and while,,, and showed poor sensitive as they have percentage of sensitivity less than 40% (see table 2). Although Staphylococcus saprophyticus; a non-agglutinating cocci, is presumed not to be pathogenic ([24]), from this study, it was observed that and were highly sensitive for staphylococcus saprophyticus, while,,, and Cotrimoxazole have over 50% sensitivity while,,, and were not sensitive to staphylococcus saprophyticus (see table 3). The non sensitivity of,,, and for Staphylococcus saprophyticus and and for Streptococcus faecalis suggested a possible pathogenic nature of the organism probably when isolated from the genitourinary tract. The resistance of Staphylococcus saprophyticus and Streptococcus faecalis to some antibiotics used, is a warning of resistance. Compared to over 200 antimicrobial agents known and employed in the management of infections all over the world ([18]), the 21 antibiotics used in this study indicated the need for other antibiotics to be studied considering susceptibility to other antimicrobial agents not cover in this study. From the results of this study, Streptococcus spp. may be antibiotic selective microorganism. In support of this assertion, resistance of uropathogens to antibiotics has been reported to be on the increase ([25]). The Ajumali s coding as shown in table 1, 2 and 3 showed that all staphylococcus spp isolated presented different antibiogram type, making them phenotypically different from one another, even though they are of the same species, by implication, indicating a very higher resolving strain differentiation. According to Momoh et al. ([18]), this typing method is so specific that it can easily pass off as a phenotypic DNA antibiogram typing method. This therefore indicates that an appropriate pneumonic coding can be able to resolve strains of the same microorganisms into their different and specific antibiogram types. This makes it easy for laboratory physician with knowledge of the various strain distribution and differentiation, to tackle multi-drug resistant (MDR) strains effectively and also in record times ([18]). Conclusively, prescription of antibiotic drugs should be based on antibiotic susceptibility pattern of isolates and should not be drug of choice in cases of blind treatment. References [1] Weichhart T, Haidinger M, Hörl, WH, Säemann MD. Current concepts of molecular defence mechanisms operative during urinary tract infection. Eur J Clin Invest; 2008; 38: [2] Dalela G, Gupta S, Jain DK, Mehta P. Antibiotic resistance pattern in uropathogens at a tertiary care hospital at Jhalawar with special reference to Esbl, Ampc β-lactamase and MRSA production. J Clin Diagn Res; 2012; 6: [3] Kluytmans, J.A.J.W., Mouton, J.W., IJzerman, E.P.F., Vandenbroucke-Grauls, C.M.J.E., Maat, A.W.P.M., Wagenvoort, J.H.T., and Verbrugh, H.A. Nasal carriage of S. aureus as a major risk factor for wound infections after cardiac surgery. J. Infect. Dis., 1995; 171: [4] Yzerman, E. P. F., H. A. M. Boelens, J. H. T. Tjhie, J. A. J. W. Kluytmans, J. W. Mouton, and H. A. Verbrugh. DAPACHE II for predicting course and outcome of nosocomial S. aureus bacteremia and its relation to host defense. J. Infect. Dis., 1996; 173: [5] Melzer, M., and Welch, C. Thirty-day mortality in UK patients with community-onset and hospitalacquired meticillin-susceptible Staphylococcus aureus bacteraemia. J Hosp Infect., 2013 [6] Brown AF, Leech JM, Rogers TR and Mcloughlin RM. Staphylococcus aureus colonisation: modulation of host immune response and impact on human vaccine design. Frontiers in Immunology, 2013; 4:507. [7] Voss, A., Doebbeling, BN. The worldwide prevalence of methicillin- resistant S. aureus. Int. J. Antimicrob. Agents, : [8] Nerurkar A, Solanky P, Naik SS. Bacterial pathogens in urinary tract infection and antibiotic susceptibility pattern. J Pharm Biomed Sci; 2012; 21: 1-3. [9] Sood S, Gupta R. Antibiotic resistance pattern of community acquired uropathogens at a tertiary care hospital in Jaipur, Rajasthan. Indian J Community Med, 2012; 37: [10] Bahadin J, Teo SSH, Mathew S. Aetiology of communityacquired urinary tract infection and antimicrobial susceptibility patterns of uropathogens isolated. Singapore Med J., 2011; 52: [11] Tseng MH, Lo WT, Lin WJ, Teng CS, Chu ML, Wang CC. Changing trend in antimicrobial resistance of pediatric uropathogens in Taiwa. Pediatr Int., 2008; 50: [12] Haider H, Zehia N, Munir AA, Haider A. Risk factors of urinary tract infection in pregnancy. J Pak Med Assoc., 2010; 60: [13] de Francesco MA, Giuseppe R, Laura P, Riccardo N, Nino M. Urinary tract infections in Brescia, Italy: Etiology of uropathogens and antimicrobial resistance of common uropathogens. Med Sci Monit., 2007; 13: [14] Leegaard TM, Caugant DA, Froholm LO, Hoiby EA. Apparent difference in antimiovrobial susceptibility as a consequence of national guidelines. Clin Microbiol Infect., 2000; 6: 290. [15] Kashef N, Djavid GE, Shahbazi S. Antimicrobial susceptibility patterns of community-acquired uropathogens in Tehran, Iran. J Infect Dev Ctries., 2010; 4: [16] Theodros G. Bacterial pathogens implicated in causing urinary tract infection (UTI) and their antimicrobial susceptibility pattern in Ethiopia. Revista CENIC. Ciencias Biológicas, 2010; 41: 1-6. [17] Orhue, P.O. Antibiogram and some indigenious plant extract susceptibility profiles of Uropathogenic Bacterial isolates from University of Benin teaching Hospital, Benin City, Ph.D Thesis Ambrose Alli University, Ekpoma, Nigeria.

6 82 Orhue P. O. et al.: Sensitivity and Antibiogram Types of Staphylococcus Species Isolated from Uropathogenic Infections [18] Momoh, A.R.M., Orhue, P.O., Idonije, O.B., Oaikhena A.G., Nwoke E.O., Momoh, A.A. The antibiogram types of Escherichia Coli isolated from suspected urinary tract infection samples. J. Microbiol. Biotech. Res., 2011, 1 (3): [19] Joghi, K.R., Onaghise, S.M., Oyide, S.M., Wenabu, S.N.C., Uriali, A. Benin. Afr. J. Clin. Microbiol. 1984, 1(1):8-13 [20] Momoh, A.R.M., Odike, M,A.C., Samuel, S.O; Momoh, A. A., Okolo, P.O. Benin Journal of Post Graduate Medicine. 2007, 9(1): [21] Momoh, A.R.M., Momoh, A.A., Okolo, P.O. Osifoh, U. C. Annuals of Irrua Medicine 2008, 2(1): [22] Miller, L.G., and Diep, B.A. Clinical practice: colonization, fomites, and virulence: rethinking the pathogenesis of community-associated methicillin-resistant Staphylococcus aureus infection. Clin Infect Dis., 2008; 46, [23] Davis, M.F., Iverson, S.A., Baron, P., Vasse, A., Silbergeld, E.K., Lautenbach, E., and Morris, D.O. Household transmission of meticillin-resistant Staphylococcus aureus and other staphylococci. The Lancet Infectious Diseases, 2012; 12, [24] Jawetz, E.. Enterbacteriaceae In: Brooks GF, Butel JS, Morse SA eds. Medical Microbiology 23rd ed Stamfordconnecticut. Appleton and Lange. 2004, Pp [25] Lutter SA, Currie ML, Mitz LB, Greenbaum LA. Antibiotic resistance patterns in children hospitalized for urinary tract infections. Arch Pediatr Adolesc Med. 2005; 159(10):