ANTIBACTERIAL EFFICACY AND TOXICOLOGICAL EVALUATION OF Periplaneta americana EXTRACTS ON SOME BACTERIA CAUSING URINARY TRACT INFECTIONS

Abstract

The use of natural products in drug discovery have largely been dominated by plants, microbes and marine organisms. However, insects offer a huge resource of potentially useful and chemically diverse compounds. This study investigated the antibacterial activity of Periplaneta americana (American cockroach) extracts against some bacteria isolated from urine samples of urinary tract infected patients. A total of 128 urine samples were collected from in-patients at the Ondo State University of Medical Sciences Teaching Hospital Akure Annex and Mother and Child hospital Akure. The collection was based on patient’s age and sex and these samples were analyzed for the presence of uropathogens. Bacterial isolates from the urine samples were characterized and identified using biochemical and molecular characteristics. The isolates were subjected to sensitivity test against conventional antibiotics using disc diffusion method. A total of 80 American cockroaches were collected and dissected into head, thorax and abdomen using a sterile surgical blade. Extracts were prepared from the three different parts using 30% Dimethyl Sulfoxide (DMSO) for homogenization. They were then centrifuged and the supernatants were purified by passing them through millipore filter. Isolates were standardized using 0.5 McFarland standard with the aid of spectrophotometer and were used for in-vitro antibacterial test. Extracts were then tested against bacterial isolates using agar well diffusion method. In-vivo antibacterial activity of P. americana extract was done using animal model. Acute toxicity text, determination of infectivity dose, infection of rats with infectivity dose of test organisms and treatment of rats with P. americana extract were done on 54 Wistar albino rats. The bacteria isolated from urine samples include Escherichia coli (44.79%), Klebsiella pneumoniae (21.87%), Staphylococcus aureus (15.63%), Proteus miriabilis (9.38%), Pseudomonas aeruginosa (6.25%), and Streptococcus pyogens. (2.08%). Females between the ages of 20-39 years showed the highest

frequency of occurrence of the disease. Extracts from the head of P. americana showed activity against E. coli (16.00±0.88mm) and S. aureus (14.33±0.58mm) only while extracts from other parts of the American cockroach showed no activity against any of the pathogens. Infection of rats with E. coli and S. aureus caused a decrease in their PCV, HB and RBC and increase in their neutrophil counts, showing a sign of infection but after treatment with P. americana extract, there was no significant difference in the PCV and WBC of the group of rats treated with P. americana extract and the group that were neither infected nor treated. Infection of rats with E. coli resulted to a severe sinusoidal congestion of the liver. After treatment with P. americana extract, a moderate sinusoidal congestion was observed. The most abundant bioactive compound identified in P. americana extract using Gas Chromatography-Mass Spectrometry is nhexadecanoic. The use of insect like cockroach in this study could be exploited for the development of various pharmacological products against bacteria associated with urinary tract infections.