Gut Microflora and its Role in Aggravation of Diarrhoea and Tissue Damage in Goats Infected with Coccidia

Abstract

Forty one faecal samples were randomly collected from apparently healthy goats from different breeds, localities, ages and sex in Khartoum State and subjected to bacteriological examination to identify normal aerobic gut flora. Ninety seven isolates were recovered. They consisted of 42 (43.3%) Gram negative and 55 (56.7%) Gram positive bacteria. Four groups of goat kids (3-5 months old) were used. Group A consisted of four kids infected with 1.5 x 106 sporulated oocysts of five Eimeria spp. viz. E. arloingi, E. crandallis, E. ninakohlykimovae, E. pallida and E. parva. Two groups (B and C) each consisted of six kids were infected with 1 x 106 sporulated oocysts of the same Eimeria spp. and each group was subdivided into two subgroups (Bl and B2 for group B and Cl and C2 for group C). The fourth group was the control uninfected. Groups Bl and Cl were treated with Oxytetracycline 5% and Amprolium, respectively, 6 days post infection (pi) Groups B2 and C2 were treated with Oxytetracycline 5% and Amprolium, respectively after the start of diarrhoea (11 days pi). In the experimental infection, about 127 isolates were recovered from the faecal samples. Seventy seven (60.62%) isolates were Gram positive and 50 (39.38%) were Gram negative bacteria. The organisms isolated were Staphylococcus spp., Streptococcus spp., Micrococcus spp., Bacillus spp., Escherichia coli, Yersinia enterocoliticia, Morganella morganii, Serratia liquefacient, Proteus spp., Edwardsiella tarda, Enterobacter spp., Alcaligenes faecalis and Chromobacterium lividum. General observations indicated that there were changes in dominant species of microflora during coccidiosis, mainly Gram's negative (E. coli) were found after onset of diarrhoea and species of Gram's positive bacteria detected decreased. In group A, 86 isolates were recovered of which 52.33% were Gram's positive (mainly Bacillus spp. 51.11%) and 47.67% were Gram's negative (mainly E. coli 25.05%). In the treated groups, 41 isolates were recovered before the start of treatment (46.34% as Gram positive and 55.66% as Gram negative). Twenty seven (48.15%) isolates as Gram positive and 51.85% as Gram negative were recovered after treatment. Animals in group A developed the disease which terminated fatally (100% mortality) 8 to 14 days after onset of symptoms. Kids in groups Bl and Cl showed no symptoms till slaughtered on day 10 (pi). Animals in group C2 died 14 to 15 days (pi) before completing the course of treatment, while kids in group B2 were alive till slaughtered after completing the treatment. Clinical signs observed were dullness, loss of appetite, general weakness and diarrhoea. Haematological parameters and body weights were affected. Macroscopic examination of the carcasses revealed emaciation and dehydration. Intestinal mucosas were haemorrhagic and intestinal contents were watery. Some mesenteric lymph nodes were enlarged and congested. Histopathological sections showed intestinal mucosal cells of the small intestine which were destroyed and colonized by different developmental stages of coccidia. Hypertrophy and hyperplasia of glandular epithelium were also observed, in addition to haemorrhage, congestion and infiltration of inflammatory cells. In large intestine, haemorrhage, congestion and cellular infiltration were seen and some sections showed different coccidial stages. The mesenteric lymph nodes were haemorrhagic and congested beside depletion of lymphocytes and presence of different sizes of schizonts. Haemorrhage and congestion were seen in sections of lung, kidney, liver and spleen. Antibiotic sensitivity tests on 3 selected isolates of E. coli showed that the organism was highly sensitive to Nitrofurantoin, Chloramphenicol, and moderately sensitive to Gentamicin, Kanamycin, Nalidixic acid and Tetracycline. The organism was found less sensitive to Streptomycin, Ampicillin and completely resistant to Penicillin G.

Preventive Medicine and Veterinary Public Health