SURVIVAL ASSESSMENT OF PATHOGENIC BACTERIA WITH ANTIBIOTIC RESISTANCE TRAITS FROM FRESH SUMMER ROYAL GRAPE: IN VITRO MICROBIAL CHALLENGE TEST

Abstract

Table grape act as a popular and mouthwatering fruit supplement over the world. Unhygienic handling of these fruits can possess a diverse threat to public health safety. Moreover, the fruit juice can serve as a nutrient for bacterial growth as well if kept in an unsanitary condition. For this purpose, five imported grape samples (Red Globe, Perlette, Calmeria, Princess and Summer Royal) were tested to assess the presence of pathogenic bacteria and drug-resistant pattern of the isolates. The total bacterial count (TBC) and total fungal count (TFC) showed the presence large amount of bacterial (ranged from 4.4 x 104 to 8.1 x 107) and fungal population on the grapes samples, especially on the skin part of the fruits. Several pathogenic isolates, Escherichia coli, Staphylococcus spp., and Pseudomonas spp. were isolated from tested grape samples. However, the presence of Salmonella spp., Shigella spp., Vibrio spp. and Klebsiella spp. were not found from any of the samples. The concerning part of the present study was drug-resistant bacterial strains isolated from supplied Fresh Summer Royal Grape. The most of the isolated bacterial spp. were resistant to all most all of the commonly used antibiotics such as ampicillin (10 µg), trimethoprim/sulfamethoxazole (25 µg), tetracycline (30 µg), ceftriaxone (30 µg), imipenem (10 µg), chloramphenicol (30 µg), azithromycin (15 µg), novobiocin (30 µg), vancomycin (30 µg), penicillin G (10 µg), ciprofloxacin (5 µg), neomycin (30 µg), levofloxacin (5 µg), kanamycin (30 µg) and cefiximycin (5 µg). No grape samples showed any kind of antimicrobial activity against both pathogenic and non-pathogenic bacteria. The survival pattern of inoculated bacterial samples in the grape sample showed a slight decrease in growth in the course of time.