Investigation of Escherichia coli septicemia and antibiotic susceptibility in neonatal lamb deaths in the Aegean region

In this study, Escherichia coli (E. coli) septicemia was investigated in neonatal (0-28 days) lamb deaths in 7 provinces of the Aegean region (Aydın, Denizli, İzmir, Kütahya, Manisa, Muğla, Uşak) between 2019-2021, and antimicrobial susceptibility was determined. The material of the study consisted of 150 lamb visceral organs and tissues (lung, liver, spleen, lymph, bone marrow and intestine). The samples were incubated in nutrient broth under aerobic conditions and then inoculated on 7% blood agar and Macconkey agar, and incubated at 37°C for 24-48 hours. Gram-negative bacilli that form grayish S-type on blood agar and pink, non-mucoid colony on Macconkey agar were evaluated as E. coli and were also confirmed by the Vitek 2 system. E. coli agent was detected in 88.66% (133/150) of the samples. Agent isolation was most common in İzmir (31/133; 23.30%) and Aydın (25/133; 18.80%). Findings in other provinces showed a similar trend. In antibiotic susceptibility test, amoxicillin-clavulanic acid, cefoperazone, erythromycin, penicillin G, gentamicin, tetracycline, trimethoprim-sulfomethoxazole and enrofloxacin commercial discs were used. Of the isolates, 110 (73.33%) were sensitive to gentamicin, 80 (53.33%) to cefoperazone, and 70 (46.66%) to amoxicillin-clavulanic acid. In addition, all of the isolates were resistant to penicillin G (100%), erythromycin (97.33%), tetracycline (81.33%), and sulfamethoxazole-trimethoprim (79.33%). As a result, E. coli septicemia characterized by visceral involvement is seen in the Aegean region. It is thought that mortality will decrease with the right treatment approaches and rational antibiotic use and will contribute positively to the economy.