Bacterial contaminants of Date palm fruits (Phoenix dactylifera) sold in Kaduna, Nigeria, and their susceptibility to antibiotics

Abstract

Background: Antibiotic resistance is a major challenge of antimicrobial therapy of infections today. Food-borne bacteria can serve as reservoir for transmission of antibiotic resistant strain. This study was aimed at determining the bacterial contaminants on dates palm fruits sold in Kaduna metropolis and to determine the antibiotic resistance pattern of the bacteria isolated.

Methodology: A total of 60 samples of Date palm fruits (Phoenix dactylifera L.) were collected randomly from five major markets in Kaduna metropolis. Total bacterial and total coliform counts were determined using pour plate method. Gram, staining, microscopy and biochemical tests were carried out to isolate the bacterial contaminants. Antibiotic susceptibility test for commonly prescribed antibiotics was also carried out through agar diffusion method and the percentage antibiotic resistance determined. Data were analysed using descriptive statistics on Microsoft Excel.

Results: The results showed that the mean total bacterial count range was 4×10⁵-2.7×10⁶. The mean coliform count range was 8×10³-1.2×10⁶. The following bacteria were isolated; Staphylococcus aureus (35.7%), Streptococcus spp (21.4%), Escherichia coli (12.5%), Bacillus subtilis (8.9%), Enterobacter spp (8.9%), Proteus mirabilis (7.1%) and Salmonella Typhi (5.4%). Gentamicin (43.2%) and cotrimoxazole (47.4%) were the most active against Gram-positive and Gram-negative isolates respectively. The bacterial isolates showed high level of antibiotic resistance with 57.1% being multidrug resistant, 10.7% extensively resistant and 5.4% were resistant to all the antibiotics tested.

Conclusion: The high level of contamination and antibiotic resistance observed in this study is alarming and of public health concern, as Date fruit is highly consumed in this part of the country. Thorough washing of Date fruits with clean water before eating is recommended.