Isolation and sequence analysis of Bartonella in small mammals in Hainan province

Objective To determine the current situation of Bartonella infection in and types of Bartonella carrying small mammals in Hainan province,providing evidence for prevention and control of Bartonella infection. Methods The rat-cage method was employed to capture small mammals,of which heart blood was collected and treated with anticoagulants. A 1∶4 dilution of 100 μl anti-coagulation blood and trypsin soy broth was inoculated onto the trypsin soybean agar culture media containing 5% de-fiber sheep blood and cultured in a 5% CO2 incubator at 37 ℃ for 45 d. Suspected colonies were smeared,Gram-and Gimanez-stained and screened under microscopy. The polymerase chain reaction (PCR) was performed for the Gram-negative bacilli with Bartonella genus-specific primers,followed by sequencing of the PCR products. The nucleic acid sequences were submitted to GenBank for similarity comparison and sequence analysis. Results A total of 6 suspected colonies were isolated from 65 samples,all being Gram-negative small bacilli,and red for Gimanez staining. The PCR results confirmed that the six strains were all Bartonella,two isolated from Rattus losea and Rattus brunneusculue each,and one from Niniventer fulvescens and Suncus murinus each. The sequence analysis suggests that the isolated Bartonella had the highest similarity with Bartonella rattimassiliensis,B. tribocorum and B. queenslandensis. Conclusion Bartonella infection was found among small mammals in Hainan province,indicating risks of infection among human beings.