Molecular Characterization and Multidrug Resistant Staphylococcus saprophyticus Isolated from Pregnant Women with Cases of Urinary Tract Infections in Some Hospitals of Bauchi Metropolis, Nigeria
F. Hassan *
Department of Microbiology, Abubakar Tafawa Balewa University, ATBU, Bauchi, Nigeria.
T. Inusa
Department of Microbiology, Abubakar Tafawa Balewa University, ATBU, Bauchi, Nigeria.
A. Salisu
Department of Microbiology, Federal University of Health Sciences, Azare (FUHSA), Bauchi State, Nigeria.
S. Ismai’l
Department of Microbiology, Abubakar Tafawa Balewa University, ATBU, Bauchi, Nigeria.
Y. Saheed
Department of Microbiology, Yobe State University, Damaturu, Nigeria.
Y. Jonah
Department of Microbiology, Abubakar Tafawa Balewa University, ATBU, Bauchi, Nigeria.
P. Moses
Department of Microbiology, Abubakar Tafawa Balewa University, ATBU, Bauchi, Nigeria.
Z. M. Kabeer
Biology Department, School of Science, Aminu Saleh College of Education, Azare, Bauchi State, Nigeria.
F. M. Ado
Department of Microbiology, University of Abuja, Abuja, Nigeria.
H. M. Habi
Department of Microbiology, University of Abuja, Abuja, Nigeria.
M. U. Usman
Department of Microbiology, University of Abuja, Abuja, Nigeria.
A. Usman
College of Nursing Science, Maiduguri, Borno State, Nigeria.
A. B. Zamo
Department of Medical Microbiology/Immunology, Federal University of Health Sciences Teaching Hospital, Azare (FUHSTHA), Bauchi State, Nigeria.
I. Mustapha
Department of Medical Laboratory Technicians, Galtima Mai Kyari College of Health Technology, Nguru, Yobe State, Nigeria.
H. S. Musa
National Health Insurance Authority, Bauchi State Office, Bauchi State, Nigeria.
M. Y. Iliyasu
Department of Microbiology, Abubakar Tafawa Balewa University, ATBU, Bauchi, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Background and Aim: Urinary Tract Infection (UTI) is one of the most frequent bacterial infections in women. Staphylococcus saprophyticus is a novobiocin-resistant coagulase-negative staphylococcus recognised as an important cause of community-acquired uncomplicated UTI, especially in pregnant women. With rising antibiotic resistance and limited data from North-East Nigeria, this study aimed to characterise multidrug-resistant S. saprophyticus and determine the genetic basis of resistance in urine specimens from pregnant women in Bauchi metropolis.
Place of Study: The study was conducted at the antenatal clinics of Abubakar Tafawa Balewa University Teaching Hospital Bauchi and State Specialist Hospital Bauchi, Bauchi metropolis, Nigeria.
Methodology: A descriptive cross-sectional study was conducted among 216 pregnant women with suspected UTI. Early-morning midstream urine was cultured on CLED and Mannitol Salt Agar. Isolates were identified using cultural, morphological, and biochemical tests and were confirmed using the VITEK 2 system. Antimicrobial susceptibility was determined by the Kirby-Bauer disc-diffusion method against 10 antibiotics according to CLSI guidelines. Multidrug resistance was defined as resistance to ≥2 classes of antibiotics. Genotypic characterisation was performed by multiplex PCR for the resistance genes mecA and aph(3)-IIIa. Data were analysed using SPSS v24.0 with chi-square and ANOVA at p < 0.001.
Results: From 216 urine samples, a total of 178 bacterial isolates were recovered. Lactobacilli spp. 55 (30.9%) and E. coli 42 (23.6%) were predominant, followed by K. pneumoniae 22 (12.4%) and K. oxytoca 18 (10.1%). Among Gram-positive bacteria, CoNS 15 (8.4%) and S. aureus 13 (7.3%) were common. S. saprophyticus accounted for 5 (33.3%) of the CoNS isolates, with an overall prevalence of 2.8%. VITEK 2 identified S. haemolyticus 6 (40.0%), S. saprophyticus 5 (33.3%), and S. epidermidis 4 (26.7%). All S. saprophyticus isolates were from women aged 20–29 years. The highest occurrence was among women with tertiary education 3 (60.0%), and among married women 2 (40.0%), divorced women 2 (40.0%), housewives 2 (40.0%), and civil servants 2 (40.0%). All 5 isolates were MDR, with 100% resistance to amoxicillin-clavulanic acid, cefuroxime, cefoxitin, tetracycline, and streptomycin. Resistance to cefotaxime and ofloxacin was 80.0%, and resistance to erythromycin was 60.0%. Ciprofloxacin and gentamicin showed 40.0% susceptibility. Molecularly, 3 (60.0%) isolates harboured mecA and 4 (80.0%) harboured aph(3)-IIIa genes.
Conclusion: This study confirms Staphylococcus saprophyticus as a clinically relevant uropathogen among pregnant women in Bauchi metropolis. The isolates exhibited a high level of multidrug resistance, with genetic evidence of mecA- and aph(3)-IIIa-mediated resistance. The findings indicate widespread antimicrobial misuse and highlight the urgent need for routine antimicrobial susceptibility testing, molecular surveillance, and antimicrobial stewardship to guide effective treatment and prevent pregnancy complications.
Keywords: Staphylococcus saprophyticus, mecA, aph(3)-IIIa, molecular characterization, urinary tract infection, pregnant women, Bauchi