Case Study Of Pathogenic Bacteria Isoiatioo, Pathaoiogic Diagnosis And Synthetic Prevention For Diarrhea In Guangxi Experimentai Cynomoigus Monkey

Introduction:Cynomolgus monkey (Macaca fascicularis) is known as an important experimental animal for medicine research over the world, and one provider region Guangxi, is the largest breeding base of farmed cynomolgus monkey of China. This study is to analyze the pathogenic and pathologic characterizations of farmed experimental cynomolgus monkeys with serious syndrome of diarrhea, and to lay the foundation for setting up further strategies about disease prevention/control and feeding management, based on epidemiological investigations of pathogenic bacteria, results of blood biochemical examination (BBE) and blood routine examination (BRE).Methods:(1) Organs and tissues were sampled from dead monkeys due to diarrhea in an experimental monkey farm during February to June,2013. Traditional bacteria isolation and culture approaches were subsequently performed to identify the responsible pathogens, as well as mouse virulence test and drug sensitive test.(2) Pathological examinations under microscope were conducted on all organ or tissue specimens by routine tissue section and Hematoxylin Eosin(H.E) dyeing assay.(3) 60 tested alive monkeys were divided into 3 groups based on the severity of their clinic disease, that 20 monkeys with no clinical symptoms were set as control group,20 with mild diarrhea were set as group 1, while the severe ones were as group 2. Pathogen isolation from nasopharyngeal and cloacal swabs was performed, followed by chemical treatment in order to test the effects of clinical control. Venous blood were also collected by day 1 and day 8 of the experiment for the uses of blood biochemical examination and blood routine examination.Results:(1) 8 stains of Streptococcus pneumoniae,7 strains of Salmonella,7 strains of pathogenic Escherichia coli, and 5 strains of Staphylococcus aureus were isolated from organs and tissues of the monkey corpses, and the mouse in vivo virulence test showed obvious pathogenicity at different level.(2) Antibacterial drug resistance of above 4 pathogen types to penicillin sodium, ampicillin, cefotaxime sodium and ofloxacin were found through the drug sensitive test. (2) Focal dark red areas of consolidation of the lung, gray-colour necrosis in different size on the spleen surface, a few pinpoint hemorrhages on the kidney surface, slight enlargement and multiple gray lesions of the liver (bleeding in some cases), intestinal mucosa hyperemia and hemorrhages especially the small intestine ducts, were respectively found by postmortem examination. And the histopathology inspection showed that alveolar wall thickness and interstitium increased, invasion by serous and various inflammatory cell subsets, degeneration and necrosis of lung alveoli epithelioid cells were also occurred on the lund specimens. Spotty necrosis in different size were scattering in hepatic lobule, different degeneration degree of hepatic cells, invasion of huge amounts of eosinophils and neutrophils intra hepatic sinusoidal and portal area were also seen. Granular degeneration and even necrosis were observed in local cardiac cells, associated with heart muscle fiber breakage or disintegration, and serous/inflammatory cells invasion. Vascular dilation and congestion in renal interstitium, and degeneration, atrophy and necrosis in tubules epithelial cells were major pathological changes after infection. The intestinal mucosa showed modified, necrosis and exfoliation, while spotty necrosis had been seen in the submucosa even the lamina layer.(3) Investigation and identification results of the clinical pathogenic bacteria on those experimental monkeys showed that, S.pneumoniae (infection rates were respectively 15% and 30%), Salmonella (10% and 30%), pathogenic E.coli(20% and 15%), and S.aureus (55% and 70%) were all found from both group 1 and group 2. BBE and BRE results indicated that compared to the relatively stable BRE indexes, rather changeable white blood cell counts were found with significantly higher monocyte and granulocyte ratios. The creatinephosphokinase (CK), blood urea nitrogen (BUN), alanine aminotransferase (ALT) and aspartate amino transferase (AST) increased whereas the levels of blood glucose (Glu).Clinical trial showed the recovery rate and effective rate in group 2 were up to 70% and 20% respectively, while the ineffictive rate was 10%. By contrast, recovery rate, effective rate and ineffective rate in group 1 were 50%,30% and 20%, respectively.Conclusions:the whole study indicated that S.pneumoniae, Salmonella, pathogenic E.coli and S.aureus are mainly responsible for the diarrhea and other associated diseases such as pneumonia, suggesting timely comprehensive control measures, as well as giving ORS and water, should be the key approaches to prevent the progression of acute diarrheal diseases from getting worse or developing into further pneumonia. The occurrence of diarrhea disease were reduced by disinfected strengthenly or/and monitored microbiological of the feeding bar shear daily, then administered regularly preventive medicine according the results of the monitoring microbiological. Furthermore, comprehensive measures were included about strengthen daily in trains employees, management of poultry farm, observation monkey condition and discover timely the abnormal animals, then giving timely treatment.