Cross-Sectional Study of Extended Spectrum β-Lactamase Genes (SHV, TEM, CTX-M and OXA) in Klebsiella Species from Clinical Specimens, in Port Harcourt, Nigeria

Abstract

Infections caused by Klebsiella sp. are increasingly becoming difficult to treat partly due to the rise in trend of extended-spectrum beta-lactamase (ESBL)-producing Klebsiella sp. This study aimed to detect the prevalence of ESBL-producing Klebsiella sp. and SHV, TEM, CTX-M, and OXA beta-lactamase encoding genes in isolates of Klebsiella sp. from two healthcare facilities in Port Harcourt. A cross-sectional study of 146 clinical specimens was analyzed using standard bacteriological identification techniques. ESBL-producing Klebsiella sp. was identified using clinical laboratory standard institute standards. Beta-lactamase genes SHV, TEM, OXA, and CTXM were extracted and amplified. Of the 146 clinical specimens; 47 (32.2%) were from males and 99 (67.8%) females. The number of Klebsiella sp. isolated from the female samples 11 (73.3%) was more than 2-fold higher than those isolated from male samples 4 (26.7%). Eighty different bacterial isolates were obtained from which 15 (18.8%) were Klebsiella sp. while 12 (80%) of the identified Klebsiella sp. were β-lactamase producing Klebsiella sp. The prevalence of the Klebsiella sp. according to the different samples were 8 (53.3%), 1 (6.7%), 2 (13.3%), 2 (13.3%), 1 (6.7%), 1 (6.7%) were obtained from urine, endocervical, sputum, high vaginal, throat, hospital environment samples respectively. Isolates 2, 4-6, and 9-11 were positive for SHV gene (293 bp); all the Klebsiella isolates were positive for TEM gene (840 bp); isolates 4-8 showed positive bands for CTX-M gene (550 bp); and isolates 2, 3, 6, 8, and 12 showed positive bands for OXA gene (908 bp). The urine sample numbered 106, 42, and 55 exhibited complete resistance to all the antibiotics used and showed different types of ESBL genes: SHV; SHV, TEM, CTX-M and OXA; and OXA, and TEM respectively. This study shows that β-lactamase genes were differentially expressed in the various types of samples collected. Again, total resistance to beta-lactam drugs may not be completely dependent on the constitutive expression of several ESBL genes but TEM is present in all the sample that showed complete resistance.