Bacteriological characterization of lower respiratory tract infection among patients attending some hospitals in Kebbi State Nigeria

Abstract

 The aetiology of lower respiratory tract infection (LRTI) is diverse and complicated, hence in most developing countries, treatment of LRTI is made usually empirically in which the etiologic agent is rarely identified. Therefore this study was designed to isolate and identify bacterial pathogens of lower respiratory tract among patients attending some hospitals in Kebbi State, Nigeria. Three hundred and fifty sputum samples were collected from six different hospitals in Kebbi State after obtaining an ethical approval from the ministry of health and informed consent from all the participants. Sputum samples were inoculated into blood agar, chocolate agar and MacConkey agar plates. The chocolate agar plates were incubated in an incubator (5% CO2) at 37 ºC for 24 hours while blood agar and MacConkey agars were incubated in an aerobic atmosphere at 37ºC for 24 hours. The bacterial isolates were identified using conventional biochemical tests and then confirmed using commercial biochemical test kit (MICROBACT) according to manufacturer’s instruction. Antimicrobial susceptibility test were determined using disc diffusion method according to CLSI guidelines. Staphylococcus aureus was the most predominant bacteria isolated in this location followed by Klebsiella pneumoniae with an estimated percentage occurrence of 31.1% and 22.2% respectively. Other bacteria isolated include Klebsiella oxytoca (13.9%), Escherichia coli (11.1%), Pseudomonas aeruginosa (5.6%), Aeromonas hydrophila (5.6%), Acinetobacter baumannii (4.6%), Burkholderia pseudomallei (2.8%) and Proteus spp (2.8%). It was found out that, the young adults and the elderly were most at risk of a severe respiratory condition. The result also shows that LRTI were more common in males than in females. Most of the isolates were susceptible to piperacilin ((51%), trimethoprim sulphamethoxazole (61%), Azithromycin (70%), Ciprofloxacin (71%) and Gentamycin (74%), in order of ranking. High resistance were recorded in almost all the βeta-lactam antibiotics,  erythromycin and vancomycin tested. In conclusion, Staphylococcus aureus was the most predominant bacteria isolated followed by Klebsiella pneumoniae while the least bacteria isolated were Burkholderia. pseudomallei and Proteus vulgaris. Lower respiratory tract infection was also more common in male and occurred mostly in young adults and elderly. Azithromycin, Ciprofloxacin, Gentamycin and piperacillin remain the useful antibiotics in the treatment of LRTIs in this location.