Occurrence and antimicrobial resistance of Campylobacter jejuni isolated from poultry and hospitalized diarrheal patients in Pakistan

The leading human enteropathogen Campylobacter jejuni ( C. jejuni ) is recognized as a major public-health concern, due to emerging multidrug resistant (MDR) strains, and associated post-infectious complications. Therefore, the present study determined the occurrence of C. jejuni in diarrheal cases and poultry, in Khyber Pakhtunkhwa Province, Pakistan, and associated antimicrobial resistance patterns. In total, 840 samples were collected from clinical and different poultry sources between May 2019 to April 2020, to determine the occurrence, seasonal variations, bacterial loads in diverse poultry samples, age-related variations in human infections as well as associated antimicrobial resistance patterns of C. jejuni , highlighting its “One Health significance” at the human-food interface. Clinical samples (n = 240) from five age-groups of hospitalized diarrhoea patients, showed occurrence rate of 39 %, which peaked in the summer and was highest in children under 5. In poultry samples, 57 % (342/600) were positive for C. jejuni , varied from 45 % (109/240) in chicken meat to 65 % (233/360) in farm samples. Except frozen meat, C. jejuni -positive poultry samples showed seasonal contamination levels, with summer having the highest bacterial loads. In chicken meat, 2 % of positive samples (2/109) had bacterial loads <1 logCFU/g, while 20 % (22/109) exceeding 3log CFU/g. Grocery store samples showed lower bacterial contamination. All human and poultry isolates (n = 436) were resistant to nalidixic acid (100 %) and none to amikacin (0 %). Of these, 66 % showed multidrug resistance, with 9 % (38/436) resistant to panel of seven out of eight antibiotics tested. This study highlights the high occurrence of and concerns about MDR C. jejuni in Khyber Pakhtunkhwa, Pakistan, particularly in young children. • C. jejuni was detected in 39 % diarrheal patients, higher in children under 5 years. • Poultry samples showed 57 % occurrence: 65 % in farm samples and 45 % in chicken meat. • Seasonal variations were observed, with the highest occurrence rates in summer. • In chicken meat, 20 % of positive samples had bacterial loads exceeding 3 log CFU/g. • 66 % isolates were multidrug resistant, 9 % resistant to 7 of 8 testes antibiotics.