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In-vitro antimicrobial susceptibility pattern of Staphylococcus aureus isolates in Umuahia, Abia state, Nigeria

EO Ekundayo, RN Ndubuisi

 

Abstract

The antimicrobial susceptibility pattern of Staphylococcusaureus in Umuahia was investigated in this study.A total of 113 strains of S. aureusconsisting of 30 isolates from clinical specimens obtained from 10 medical Laboratories and 83 isolates from nasal swabs of University students in Umuahia, were tested against 10 antimicrobial agents using the disc agar diffusion method. Resistance to penicillin, ampicillin, cloxacillin and tetracycline was 100% among strains isolated from clinical specimens. The clinical isolates also exhibited high rates of resistance to chloramphenicol (97%) and erythromycin (97%). Seven (23%) of these isolates were sensitive to Gentamicin and 6 (20%) to Streptomycin. Likewise, all the 83(100%) and 82 (98.8%)were resistant to penicillin and cloxacillin, respectively.Isolates from nasal passages appeared to be less resistant to chloramphenicol (54.2%), gentamicin (43.4), streptomycin (31.3%) and tetracycline (51.8%). Ampicillin did not produce any zone of inhibition against 29 (96.7%) isolates from clinical specimens and only slightly inhibited one with zone of inhibition of 8mm. Nineteen of the isolates manifested low to high level of resistance to chloramphenicol with mean zone of inhibition ranging from 15. 8± 0.7 mm to 9.8± 2.0 mm. All the isolates were completely resistant to penicillin and cloxacillin with no zone of inhibition at all. In the case of gentamicin, 5 (16.7%) had intermediate susceptibility (mean zone of inhibition 14±0 mm), 12(40%) had mean inhibition zone of 9.6±2.9 mm and 6(20%) were not inhibited. This study shows that S. aureus strains isolated from clinical specimens and healthy students in Umuahia are highly resistant to common antibiotics. This may not be unconnected with indiscriminate use of antibiotics and calls for more control and rational use of antibiotics to minimize the rate of development of resistance to other antibiotics.

Key words: Staphylococcus aureus, antimicrobial resistance, disc agar diffusion, antibiotic susceptibility

French Abstract

Le profil de sensibilité antimicrobienne de Staphylococcus aureus à Umuahia a été recherché dans cette étude. Au total, 113 souches de S. aureus composé de 30 souches provenant d’échantillons cliniques obtenus à partir de 10 laboratoires médicaux et 83 souches d’écouvillons nasaux des étudiants universitaires à Umuahia, ont été testées contre 10 agents antimicrobiens par la méthode de diffusion disque sur gélose. La résistance à la pénicilline, l’ampicilline, la cloxacilline et la tétracycline a été de 100% chez les souches isolées d’échantillons cliniques. Les souches cliniques ont également présenté des taux élevés de résistance au chloramphénicol (97%) et à l’érythromycine (97%). Sept (23%) de ces souches étaient sensibles à la gentamicine et 6 (20%) à la streptomycine. De même, tous les 83 (100%) et 82 (98,8%) étaient résistants respectivement à la pénicilline et à la cloxacilline. Les souches de voies nasales semblaient être moins résistantes au chloramphénicol (54,2%), à la gentamicine (43,4), à la streptomycine (31,3%) et à la tétracycline (51,8%). L’ampicilline n’a produit aucune zone d’inhibition contre 29 (96,7%) souches provenant d’échantillons cliniques et seulement légèrement inhibées avec une zone d’inhibition de 8mm. Dix-neuf souches ont manifesté un faible niveau élevé de résistance au chloramphénicol avec une zone d’inhibition moyenne allant de 15. 8 ± 0,7 mm à 9.8± 2,0mm. Toutes les souches étaient complètement résistantes à la pénicilline et à la cloxacilline sans zone d’inhibition. Dans le cas de la gentamicine, 5 (16,7%) souches avaient une sensibilité intermédiaire (zone d’inhibition moyenne de 14 ± 0 mm), 12 (40%) souches ont eu une zone d’inhibition moyenne de 9,6 ± 2,9 mm et 6 (20%) souches ne ont pas été inhibées. Cette étude montre que les souches de S. aureus isolées  à partir d’échantillons cliniques et des étudiants en bonne santé à Umuahia sont très résistantes aux antibiotiques courants. Cela peut ne pas être en rapport avec l’utilisation sans discernement des antibiotiques et des appels pour plus de contrôle et d’utilisation rationnelle des antibiotiques afin de minimiser le taux de développement d’une résistance à d’autres antibiotiques.

Mots clés: Staphylococcus aureus, résistance aux antimicrobiens, disque de diffusion sur gélose, sensibilité aux

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In-vitro antimicrobial susceptibility pattern of Staphylococcus aureus isolates in Umuahia, Abia state, Nigeria

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Profile of Infections in Intensive Care Unit (Icu) in a Central Nigeria Tertiary Hospital

KC Iregbu, SA Sonibare

 

Abstract

Background: Intensive Care Units (ICUs) accommodate the most seriously ill patients in a relatively confined environment. Increased duration of stay, increased number of indwelling and invasive devices and prolonged or inappropriate use of antibiotics are common features of ICUs, with consequent or associated increase in selection of multi-resistant  pathogens, morbidity and mortality.
Objectives: To determine the identity and antimicrobial resistance pattern of organisms commonly associated with infections in the ICU of the hospital.
Method: A retrospective study of Intensive Care Units (ICU) infections in NHA over a three-year period January 1st, 2010 to December 31st, 2012 was conducted through review and analysis of laboratory data.
Results: Data for 79 specimens were fully analysed; 35(44%) from urine, 17 (22%) from blood, 6 (8%) from tracheal specimens and 8 (10%) from wound. Forty-one (52%)of the specimens yielded growth;16 (20%) from urine, 8 (10%) from wound, 6 (8%) from tracheal specimens,3(4%) from blood and others 8(10%). 14(34%) out of the 41 isolates were Escherichia coli, 8 (20%) Pseudomonas aeruginosa, 6 (15%) were Staphylococcus aureus and 6 (15%) Klebsiella pneumoniae. Three (4%) of the specimens
yielded mixed growths while another 3 (4%) yielded Candida species. Sensitivity of E. coli to third generation cephalosporins ranged from 62-72%and 90% to imipenem. For Klebsiella pneumoniae it was 67-75% to third generation cephalosporins and 100% to imipenem. Pseudomonas aeruginosa was 71% and 83% sensitive to ceftazidime and imipenem respectively. Staphylococcus aureus was 67% and 83% sensitive to amoxicillin-clavulanate and imipenem respectively. Susceptibility of all
these isolates to fluoroquinolones and aminoglycosides remained poor.
Conclusion: The isolates from the ICU were same as common in clinical specimens. There was wide variability in resistance with a tendency to increase over time. This trend needs to be monitored while antibiotic stewardship should be emphasised.

Key words: Intensive care units (ICU), nosocomial Infections, antibiotic susceptibility.

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Profile of Infections in Intensive Care Unit (Icu) in a Central Nigeria Tertiary Hospital

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Prevalence and antibiotic susceptibility of AmpC and ESBLs producing clinical isolates at a tertiary health care center in Kano, north-west Nigeria

I Yusuf, M Haruna, H Yahaya

 

Abstract

The increase in production of Extended Spectrum Beta Lactamase (ESBL) and Amp C beta lactamase among clinical isolates in our hospitals is of utmost importance. Failure to detect these enzymes in many of our hospitals has greatly led to treatment failure and uncontrolled spread of multi drug resistant pathogens. It was for this purpose that the present study was conducted to determine the prevalence, distribution and susceptibility pattern of Gram negative bacteria producing ESBLs and Amp C beta lactamases in the largest tertiary health care provider in Kano, North-West Nigeria. A total of 75 ESBL and 10 AmpC producing bacteria were involved in the study which were obtained from a study involving 500 Gram negative clinical bacterial isolates from various hospital wards over a period of 9 months from Aminu Kano Teaching Hospital (AKTH), Kano, Nigeria. Isolates were screened for ESBLs and AmpC using Double Disc Diffusion Method and Amp C Disc test respectively. All confirmed ESBL and Amp C producing isolates were tested for susceptibility to sixteen (16) different antibiotics by the Disc Diffusion Method (DDM). The prevalence of ESBLs was high in Shigella spp. (1/2 or 50%), followed by Klebsiella pneumoniae (10/50 or /20%), and E. coli (47/247 or 19.3%) while Amp C producers were detected more in Klebsiella pneumoniae (4%) and E. coli (2.8%). Of the specimens screened, distribution varies between ESBL and AmpC producers, but more prevalent in urinary tract pathogens in both. Highest prevalence of ESBLs and AmpC producers was recorded in intensive care units and surgical wards. ESBL and AmpC production in the hospital is not sex dependent statistically, thought higher in males (52 and 60%) than in females (48 and 40%) for ESBL and AmpC respectively. ESBL and AmpC producers were both sensitive to Imipenem, Nitrofurantoin and Levofloxacin and resistance to Amoxycillin, Ceftazidime and Tetracycline. The study indicates the occurrence of ESBL and AmpC producers in our tertiary health provider, widely distributed in various clinical samples, wards
and sexes and are multi drug resistant posing serious threat in managing life threatening infections.

Key words: prevalence, distribution, ESBL producers, Amp C producers, antibiotic susceptibility

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Prevalence and antibiotic susceptibility of AmpC and ESBLs producing clinical isolates at a tertiary health care center in Kano, north-west Nigeria

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Detection of Amp C Beta Lactamases in Clinical Isolates of Escherichia coli and Klebsiella

CO Akujobi, NN Odu, SI Okorondu

 

Abstract

Detection of AmpC-mediated resistance in Gram negative organisms poses a problem due to misleading results in phenotypic tests. There are no recommended guidelines for detection of this resistance mechanism and there is a need to address this issue as much as the detection of extended spectrum beta lactamases (ESBLs) since both may co-exist and mask each other. Several methods have been used to detect the presence of AmpC β-lactamase production in some isolates but most of these methods are not reliable. There is a need for a reliable method of evaluating the presence of AmpC β-lactamases in clinical isolates. A total of 81 consecutive non repetitive clinical isolates of Escherichia coli(n=40) and Klebsiella spp. (n=41) were screened for AmpC production by disc diffusion method using cefoxitin (30 Zg) disc and confirmed by inhibitor based test using boronic acid as inhibitor. A total of 16 E.coli isolates (40%) and 16 Klebsiella isolates (39.02%) screened harbored AmpC enzymes, of which 43.75% of E.coli and 56.25% of Klebsiella isolates coproduced ESBL enzymes. Pure AmpC production was observed in 56.25% of E.coli and 43.75% of Klebsiella isolates. The inhibitor based test was useful in identifying cefoxitin susceptible AmpC producers and could also effectively differentiate ESBL from AmpC producing isolates.

Keywords: ESBL, antibiotic susceptibility, clinical samples, β-lactam disks.

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Detection of Amp C Beta Lactamases in Clinical Isolates of Escherichia coli and Klebsiella

 

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Microbial Spectrum Of Pelvic Inflamatory Diseases In Nguru, Nigeria

KO Okon, R Ayilara, K Bello, A Uba, TA Aniesona

 

Abstract

Pelvic inflammatory diseases, a leading gynecological problem worldwide, are associated with socio-economic and psychological costs. A retrospective study of 1350 high vaginal swabs analyzed between Jan-Dec. 2005, showed that 845 (62.8%) were positive for 9 microorganisms by culture/or wet preparation. Microbial growth was found in 645 (76.3%) cases. Polymicrobial growth was found in 90 (10.7%), fungal growth in 110 (13.0%)
cases, and 3(0.4%) yielded anaerobic growth. Staphylococcus aureus accounted for 355 (42.0%) cases, followed by Escherichia coli 190 (22.5%), Trichomonas vaginalis 100 (11.8%) Candida spp and Neisseria gonorrhoeae 70 (8.3) and the least, Pseudomonas spp 5 (0.6%) Microbial-associated infection was prominent in the group 21-30 years old (46.6%) and 31-40 (23.9%) years respectively. Antibiotic susceptibility pattern showed that mean
susceptibility greater than 50% were recorded with ofloxacin 80%, ceftazidime 80%, rifampicin 81.9% compared to mean susceptibility less that 50% recorded with trimethoprim-sulthamethoxazole 34.7%, and ampicillin 26.1%. In conclusion, the reported microbial-associated infection in PID with a prevalence of 62.8% is of public health importance. Early diagnosis of causative agents and prompt institution of chemotherapeutic agents will help to
prevent clinical complications that are expensive to treat.

Keywords: pelvic inflammatory diseases, microorganisms, antibiotic susceptibility.

African Journal of Clinical and Experimental Microbiology Vol. 9 (3) 2008: pp. 157-165

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ANTIBIOTIC SUSCEPTIBILITY PATTERN AND MULTIPLE ANTIBIOTIC RESISTANCE INDEX OF PSEUDOMONAS AERUGINOSA URINE ISOLATES FROM A UNIVERSITY TEACHING HOSPITAL

BO Olayinka, OS Olonitola, AT Olayinka, EA Agada

 

Abstract

Urine samples submitted to the Medical Microbiology diagnostic laboratory of the Ahmadu Bello University Teaching Hospital, Zaria, were routinely screened for Pseudomonas aeruginosa over a three-month period with 13/150 (8.67%) of the pathogenic bacteria isolated positively identified. All the isolates were resistant to the cheap, commonly available antibiotics; rifampicin, ampicillin/cloxacillin, erythromycin, chloramphenicol and ampicillin but were uniformly susceptible to ciprofloxacin. The high prevalence of multidrug resistance indicates a serious need for broad-based, local antimicrobial resistance surveillance for continuous tracking of antibiotic resistance trends among all clinically relevant isolates and introduction of effective interventions to reduce multidrug resistance in such pathogens.

Key Words: Pseudomonas aeruginosa, antibiotic susceptibility, multiple antibiotic resistance, urinary tract infection

Afr. J. Clin. Exper. Microbiol. 2004; 5(2): 198 – 202.

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INHIBITION OF SWARMING BY UREA AND ITS DIAGNOSTIC IMPLICATIONS AMONG UROPATHOGENIC PROTEUS SPECIES FROM LAGOS, NIGERIA

B.A. Iwalokun, K.A. Akinsinde, N. Nkiruika

 

Abstract

The anti-swarming property of urea and effects on antibiotic susceptibility among 52 uropathogenic Proteus strains from Lagos, Nigeria were investigated. Urea caused a reduction in swarming and number of swarmed cells at 0.5% (n = 42, DOCZ = 15.5mm), 0.75% (n= 24, DOCZ = 10.7mm), 1% (n = 17, DOCZ = 3.4mm) and 1.25% (n = 8, DOCZ = 1.7mm).  Compared to DOCZ obtained at 0.5% urea, the further reduction in DOCZ at other urea concentrations was found to be significant (p < 0.05).  Urea at less than 0.75% allowed identification of E. coli, K. pneumoniae and S. saprophyticus in mixed cultures containing Proteus spp, while colonies of Pseudomonas aeruginosa were distinctly identified at 1% urea with swarming restrained at 1.25% urea.  At 1.25% urea, antibiotic susceptibility testing by agar diffusion method revealed significant increase and decrease in the number of Proteus strains that showed resistance to amoxicillin and nitrofurantoin. Compared with the control, significant increases in the MICs of gentamicin or nitrofurantoin and streptomycin were found at $ 0.5% and $ 0.75% urea respectively (p<0.05). The identification of extended spectrum beta lactamases (ESBL) producing strains were unaffected by urea.  This study has demonstrated urea induced swarming inhibition of uropathogenic Proteus in vitro.  However, results suggest the use of urea with great caution in diagnostic practices for optimal clinical and public health benefits in Nigeria.

Keywords: Antibiotic susceptibility, anti-swarming, urea, uropathogenic proteus, Nigeria, DOCZ = Diameter of outermost colony zone mean value

(Af J Clinical & Exp Microbiology: 2003 4(2): 18-28)