Abstract

Systemic bacterial infections affect almost all part of the human body systems leading to infections such as urinary tract infections, septicemia, meningitis, pneumonia, peritonitis and gastritis. Carbapenems have been used as drug of choice in the treatment of systemic infections. Studies have indicated that Enterobacteriaceae are producing enzymes such as carbapenemases, which inactivate carbapenems.  There  is  limited  treatment  option  for  systemic  infections  caused  by  carbapenem- resistant Enterobacteriaceae. Systemic infections keep increasing; hence, the determination of the effective treatment options of carbapenem-resistant Enterobacteriaceae is important for quality healthcare delivery. In this laboratory studies, agar well diffusion and well microplate dilution of the ethanolic extract of the guava leaves was used to determine the effectiveness of Psidium guajava on carbapenem-resistant K. pneumoniae. The antimicrobial compounds responsible for the antibacterial activity were screened using standard methods. The active zones of inhibition were observed in  P. guajava leaves extract concentrations of 50, 100 and 200 mg/ml. The minimum inhibition concentration and minimum bactericidal concentration of ethanolic extract of guava leaves was 6.25 mg/ml indicating significant antibacterial activity against the carbapenem-resistant K. pneumoniae. The antibacterial activity of the leaves extract may be attributed to the presence of flavonoids and other antimicrobial phytochemicals in the guava leaves extract. The outcome of this baseline laboratory studies indicates the possibility of producing efficacious antibiotic to treat carbapenems-resistant systemic infections. The determination of the toxicological effect of the isolated active antimicrobial compounds of guava leaves extract is worth following in subsequent studies.

Key words: Psidium guajava, phytochemicals, Carbapenem, Carbapenem-resistant Klebsiella pneumonia.

Abbreviation

CPE, Carbapenamase producing Enterobacteriaceae; CRE, Carbapenamase resistant Enterobacteriaceae; CPMR, Centre for Plant Medicine Research; CLSI, Clinical and Laboratory Standards Institute; DMSO, Dimethyl Sulphoxide; DZI, diameter zone of inhibition;  E. coli; Escherichia coli; ESBL, extended-spectrum beta-lactamase; INT, p-Iodonitrotetrazolium violet; MIC; minimum inhibitory concentration; MBC, minimum bactericidal concentration; MHA, Mueller Hinton Agar; P. guajava; Psidium guajava; SDW, sterile distilled water.