OBJECTIVETo find out the vector ability and function of Nosopsyllus wualis leizhouensis in the transmitting plague.

METHODSIn T: 19 degrees C +/- 1 degrees C, RH: 85% +/- 5%, data regarding the vector ability as cluster spreading, single flea spreading, single flea transmitting plague to single animal, formative bacterial embolus and infection fleas life-span through experiments was gathered.

RESULTSThe rate of infection on fleas was 94.64%, with 100% transmission rate of colony to spread, and 30% from single flea spreading to single animal. In the experiment of single flea transmission, all of the 388 rattus loseas were bitten by the fleas with bacterial, but only 9 animals were characteristically infected with the transmission potential, vector efficiency, survival potential of embolus, vector index as 0.360, 0.257, 0.868 and 0.223 respectively. The mean survive days of infected flea feed with blood were 17.58 (1 - 58), and the mean survive days of hunger infected flea were 7.25 (1 - 16). Formative bacterial embolus days were 8.80 (2 - 16) and the rate of embolus flea was 78.12%.

CONCLUSIONNosopsyllus wualis leizhouensis could serve as vector and important in the mode of plague transmittion.

Animals ; Female ; Insect Vectors ; microbiology ; Male ; Plague ; transmission ; Rats ; Siphonaptera ; microbiology

OBJECTIVETo analyze the results of etiology and serology of plague among human and infected animals in Qinghai province from 2001 to 2010.

METHODSThirty-seven cases of human infected with plague, 53 541 different animal samples, 5 685 sets of vector insects flea and 49 039 different animal serum samples were obtained between 2001 and 2010. A total of 7 811 samples of serum from healthy farmers and herdsmen in 14 counties in Qinghai from 2005 to 2007 were collected. Yersinia pestis (Y. pestis) were detected in visceral and secretions from human, infected animals and vector insects, respectively. Plague antigen was detected by reverse indirect hemagglutination assay (RIHA) in those samples. Indirect hemagglutination assay (IHA) was used to test plague FI antibody in serum of human and infected animals.

RESULTS37 human plague cases were confirmed, 21 strains of plague Y. pestis were isolated from human cases and 14 positive were detected out. 133 of 7 811 samples of human serum were IHA positive, with the positive rate at 1.7%. A total of 146 strains of plague were isolated from infected animals and vector insects, 99 out of which were from infected animals, with a ratio of Marmota himalayan at 72.7% (72/99) and the other 47 were from vector insects, with a ratio of callopsylla solaris at 68.1% (32/47). The number of IHA and PIHA positive were 300 and 10, respectively. A total of 3 animals and 3 insects species were identified as new epidemic hosts for plague. The natural plague focus of Microtus fuscus was discovered and confirmed and coexisted with natural focus of Marmota himalayan in Chengduo county, Yushu prefecture. The epidemic situation of plague is distributed mainly in Haixi, Yushu and Hainan prefectures.

CONCLUSIONFrom 2001 to 2010, animal infected with plague was detected in successive years and human plague was very common in Qinghai. New infected animals and vector insects species and new epidemic areas were confirmed, hence the trend of plague prevalence for humans and animals is very active in Qinghai province.

Animals ; Antibodies, Bacterial ; blood ; China ; epidemiology ; Disease Vectors ; Humans ; Insect Vectors ; microbiology ; Plague ; epidemiology ; transmission ; Yersinia pestis ; classification ; isolation & purification

OBJECTIVEAssessment of the bacterium L. sphaericus as a dual-action candidate for biological control of mosquito-borne diseases and bioremediation of toxic metals.

METHODSLarvae of the mosquito, C. quinquefasciatus, were first evaluated for metal tolerance and then exposed to 5 ppm cadmium, chromium, arsenic, and lead in assays together with seven strains of L. sphaericus. A probit regression analysis was used to estimate the LC(50) of Cd, Cr, As, and Pb to C. quinquefasciatus. An analysis of covariance and multifactorial ANOVA examined the metal biosorption and larvicidal properties of the seven strains of L. sphaericus.

RESULTSWe found that L. sphaericus adsorbed the toxic metal ions and was toxic against mosquito larvae. The L. sphaericus strain III(3)7 resulted in a larvae mortality of over 80% for all the tested metals. This strain also exhibited the capacity to adsorb 76% of arsenic, 32% of lead, 25% of chromium, and 7% of cadmium.

CONCLUSIONThis study found combined metal adsorption and larval toxicity associated with three strains of L. sphaericus [III(3)7, OT4b.31, and CBAM5]. This suggests that a combination of these strains shows strong dual potential for biological control of mosquitos in heavy metal-contaminated areas and remediate the heavy metal contamination as well.

Animals ; Bacillaceae ; physiology ; Culicidae ; microbiology ; Host-Pathogen Interactions ; Insect Vectors ; Larva ; microbiology ; Metals, Heavy ; metabolism ; toxicity ; Water Pollutants, Chemical ; metabolism ; toxicity

Pathogens like bacteria and protozoa, which affect human and animal health worldwide, can be transmitted by vectors like ticks. To investigate the epidemiology and genetic diversity of bacteria and protozoans carried by ticks in Chengmai county of Hainan province, China, 285 adult hard ticks belonging to two species [
Anaplasmataceae/isolation & purification* ; Animals ; Chaperonin 60/genetics* ; China ; Citrate (si)-Synthase/genetics* ; Coccidia/isolation & purification* ; Coxiellaceae/isolation & purification* ; Insect Vectors/microbiology* ; Islands ; Ixodidae/microbiology* ; Phylogeny ; Piroplasmia/isolation & purification* ; RNA, Ribosomal, 16S/genetics* ; RNA, Ribosomal, 18S/genetics*