Antibacterial effect of kitchen herbs against pathogenic multidrug-resistant E. coli isolates from calf diarrhoea

Calf diarrhoea remains the biggest challenge both in the small and large farms. Infectious diarrhoea is associated with many pathogens, Escherichia coli being one, but majority are systematically treated with antibiotics. Since antimicrobial resistance (AMR) is a growing menace, the need to find alternative prophylactic solutions using popular kitchen herbs such as Trachyspermum ammi (carom seeds), Curcuma longa (turmeric) and cinnamon (Cinnamomum sp.) extracts is been investigated against virulent form of E. coli isolated from calf diarrhoea. The virulence factors identified in these isolates were ST (32.5%), LT (20%), eaeA (15%), stx1 (2.5%) and stx2 (5%) with the occurrence of the most common serogroups as O18 (15%) followed by O111 (12.5%). Highest resistance was seen with beta lactam + beta lactamase inhibitor (amoxicillin/clavulanic acid) followed by beta lactams (ampicillin, cefuroxime and cefepime). The zone of inhibition due to cinnamon (methanol) and carom seed (ethanol) extracts (500 to 250 μg/mL concentration) on E. coli bacteria was >19 mm, respectively. Turmeric, cinnamon and carom had the potency of inhibiting the pathogenic E. coli which maybe suggestive of its use in calf diets as prophylaxis against diarrhoea.

Diagnosis of mixed gastrointestinal nematode infection in goat by an indirect-ELISA

An indirect-ELISA for the diagnosis of mixed gastrointestinal (GI) nematode infection comprising Oesophagostomum, Haemonchus and Trichuris species was standardized using crude somatic antigen of Oesophagostomum columbianum (CSAg-Oc) and sera of slaughtered goats with known parasitological status including Oesophagostomum, Haemonchus, and Trichuris (strong positive), Haemonchus and Trichuris (weak positive) and parasite free goats (negative). Two cut-off points, i.e. higher and lower cut-off were determined using the strong positive, weak positive and the negative control sera of goats. Thus the test sera having optical density (OD) values greater than the higher cut-off were considered positive for mixed infection with all the three nematode species, intermediate between the higher and the lower cut-off values were considered positive for mixed infection of Haemonchus and Trichuris, and less than the lower cut-off value were considered negative for any of these three nematode species. The sensitivity, specificity and accuracy of the ELISA for diagnosis of mixed GI nematodoses were 81.25, 93.18% and 90.00%, respectively, while it was 92.86% sensitive, 75.00% specific and 91.67% accurate for the diagnosis of mixed infection with Haemonchus and Trichuris. The ELISA, so standardized, detected 27.78% sero-prevalence of Oesophagostomum plus Haemonchus and Trichuris infection and 38.89% percent of Haemonchus and Trichuris infection in the field goats. The standardized assay might be exploited as a diagnostic tool and also for sero-epidemiological study of two important GI nematodes of goats.