Rickettsia japonica Infections in Humans, Zhejiang Province, China, 2015.

We investigated 16 Japanese spotted fever cases that occurred in southeastern China during September-October 2015. Patients had fever, rash, eschar, and lymphadenopathy. We confirmed 9 diagnoses and obtained 2 isolates with high identity to Rickettsia japonica strain YH. R. japonica infection should be considered for febrile patients in China.

Misdiagnosed murine typhus in a patient with multiple cerebral infarctions and hemorrhage: a case report.

BACKGROUND: Rickettsias cause a wide spectrum of tick-, flea-, or mite-borne infections. Rickettsial infections have no classical manifestations and can often lead to encephalitis, which can be fatal if improperly diagnosed. CASE PRESENTATION: A 74-year-old male farmer was admitted to the hospital with fevers and a headache that had lasted for 10 days, followed by 4 days of unconsciousness, and his condition continued to deteriorate. Images showed multiple acute lesions in the brain stem, and bilateral cerebral and cerebellar hemispheres. He was finally diagnosed with endemic typhus and treated with antibiotics that resulted in improvement. CONCLUSION: The present report describes a patient with a rickettsial infection and subsequent deterioration to coma because of an initial misdiagnosis. Because of the similarity to other infectious diseases, physicians should be more vigilant towards the history and radiologic results to ensure early detection and avoid complications which may prove to be fatal.

[Detection of enterohemorrhagic Escherichia coli O157:H7 by loop-mediated isothermal amplification].

OBJECTIVE: To develop a loop-mediated isothermal amplification (LAMP) method for rapidly diagnosing of Escherichia coli (EHEC) O157:H7 in pathogen detection department or small-scale laboratories. METHODS: Primers for LAMP test were designed by targeting the antigen coding rfbE of EHEC O157:H7, the Shiga-like toxin stx2 and the fliC encoding gene of H7 flagella antigen, respectively. The reaction condition and reaction system of LAMP were optimized. 2 EHEC O157:H7 type strains, 17 local strains and 33 other enterobacteria were analyzed to evaluate the LAMP's specificity and sensitivity. The results of the LAMP reaction were also compared with routine PCR method. RESULTS: The amplification products of O157 which had the corresponding target genes turned green by visual inspection and had ladder-like pattern on the gel, but products of other enterobacteria remained orange by visual examination and had no band on the gel. The detection results of LAMP were the same as of routine PCR method. The reaction time of the LAMP method was only 1.5 hours and the detection limit of LAMP assay was 26 CFU/reaction. In addition, the LAMP results could be determined only by visual inspection. CONCLUSION: LAMP assay is rapid, specific, and sensitive for the detection of EHEC O157:H7. This method might not only reduce the dependence of complicated equipments but also be a potential method for wider use in pathogen detection department, small-scale laboratory, emergency motor vehicle or field survey.

Deficiency in endothelin receptor B reduces proliferation of neuronal progenitors and increases apoptosis in postnatal rat cerebellum.

Endothelins regulate cellular functions in the mammalian brain through the endothelin receptors A and B (EDNRA and EDNRB). In this study, we investigated the role of EDNRB on cell proliferation in the cerebellum by using the spotting lethal (sl) rat, which carries a naturally occurring deletion in the EDNRB gene. Proliferating cells in the three genotypes, wild-type (+/+), heterozygous (+/sl) and homozygous mutant (sl/sl) rats were labelled by intraperitoneal injection of 5-bromo-2'-deoxyuridine (BrdU) at postnatal day 2. The density of BrdU-positive cells (per mm(2)) in the external germinal layer of sl/sl rats (Mean +/- SEM, 977 +/- 388) was significantly reduced compared to +/+ (4915 +/- 631) and +/sl (2304 +/- 557) rats. Subsequently, we examined the effects of EDNRB mutation on neural apoptosis by terminal deoxynucleotidyltransferase-mediated dUTP nick end-labelling assay. This showed that the density of apoptotic cells in the cerebella of sl/sl rats (9.3 +/- 0.5/mm(2)) was significantly more increased than +/+ rats (4 +/- 0.7). The expression of brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) were measured with standard ELISA, but were unchanged in all genotypes. These results suggest that ENDRB mediates neural proliferation and have anti-apoptotic effects in the cerebellum of the postnatal rat, and that these effects are independent of changes in the expression of BDNF and GDNF. Our findings will lead to better understanding of the morphological changes in the cerebellum of Hirschsprung's disease patients with congenital EDNRB mutation.

Activation of alpha 2A adrenoceptors alters dendritic spine development and the expression of spinophilin in cultured cortical neurones.

alpha2 adrenoceptors have been shown to regulate the development of dendrites in mammalian cortical neurones. In this study we have investigated how agonists of alpha2 adrenoceptors affect length and density of dendritic spines in cultured cortical neurones from C57/B6 mice. A twenty-four hour incubation of 14 day old cultured neurones with UK 14304, an alpha2-adrenoceptor agonist, resulted in a significant increase in the average length and density of dendritic spines. Furthermore, incubation of neurones with the selective alpha 2A agonist guanfacine resulted in 1.2-fold increase in spine length and 1.8-fold increase in spine density. These effects were blocked by RX 821002 and BRL 44408, alpha2- and alpha 2A-adrenoceptor antagonists, respectively. The observed changes in the density and length of dendritic spines were correlated with increased expression of spinophilin, a key cytoskeletal protein in the formation and maintenance of dendritic spines, and a decrease in the phosphorylation of spinophilin on serine residues. The latter finding points to a possible mechanism by which adrenoceptors may regulate spinophilin function in dendritic spine development and structure in cortical neurones in vitro.

[An immunofluorescence assay for the detection of SARS associated coronavirus antibody based on recombinant nucleocapsid antigen and its application].

OBJECTIVE: To establish a new technique for SARS-CoV antibody test to detect infection of severer acute respiratory syndrome (SARS). METHODS: Nucleocapsid gene was obtained by reverse transcription and polymerase chain reaction from a SARS patient and inserted into the vector pFastBacHTa expressing baculovirus. Insect Sf9 cells were transfected with the recombinant baculovirus expressing SARS nucleocapsid antigen and then cultured, fixed by acetone so as to make SARS-specific antigen. Immunofluorescence assay (IFA) technique and plaque reduction neutralization test (PRNT) were used to detect 7 samples of sera of 4 newly diagnosed SARS patients collected in different days, 48 samples of convalescent sera of SARS patients, 24 serum samples of healthy person undergoing physical examination, and 40 serum samples from non-SARS patients with fever by double blind test. RESULTS: The recombinant SARS-specific antigen reacted only with SARS positive sera but not with normal sera. Double blind test showed that 45 of the 46 PRNT positive sera were IFA positive with an accordance rate of 97.8%. 7 samples of sera from 4 SARS patients in acute progressive stage in Guangdong province were all IFA positive. SARS antibody could be detected since the sixth day after onset, and the titer increased from 1:40 to 1:600 on the ninth day. CONCLUSION: Immunofluorescence assay is highly specific and sensitive in detection of SARS. This reagent is safe and easy to prepare.

Severe acute respiratory syndrome-associated coronavirus genotype and its characterization.

OBJECTIVE: To study the severe acute respiratory syndrome (SARS)-associated coronavirus genotype and its characteristics. METHODS: A SARS-associated coronavirus isolate named ZJ01 was obtained from throat swab samples taken from a patient in Hangzhou, Zhejing province. The complete genome sequence of ZJ01 consisted of 29,715 bp (GenBank accession: AY297028, version: gi: 30910859). Seventeen SARS-associated coronavirus genome sequences in GenBank were compared to analyze the common sequence variations and the probability of co-occurrence of multiple polymorphisms or mutations. Phylogenetic analysis of those sequences was done. RESULTS: By bioinformatics processing and analysis, the 5 loci nucleotides at ZJ01 genome were found being T, T, G, T and T, respectively. Compared with other SARS-associated coronavirus genomes in the GenBank database, an A/G mutation was detected besides the other 4 mutation loci (C:G:C:C/T:T:T:T) involved in this genetic signature. Therefore a new definition was put forward according to the 5 mutation loci. SARS-associated coronavirus strains would be grouped into two genotypes (C:G:A:C:C/T:T:G:T:T), and abbreviated as SARS coronavirus C genotype and T genotype. On the basis of this new definition, the ZJ01 isolate belongs to SARS-associated coronavirus T genotype, first discovered and reported in mainland China. Phylogenetic analysis of the spike protein gene fragments of these SARS-associated coronavirus strains showed that the GZ01 isolate was phylogenetically distinct from other isolates, and compared with groups F1 and F2 of the T genotype, the isolates of BJ01 and CUHK-W1 were more closely related to the GZ01 isolate. It was interesting to find that two (A/G and C/T) of the five mutation loci occurred in the spike protein gene, which caused changes of Asp to Gly and Thr to Ile in the protein, respectively. CONCLUSION: Attention should be paid to whether these genotype and mutation patterns are related to the virus's biological activities,epidemic characteristics and host clinical symptoms.

Rural residents in China are at increased risk of exposure to tick-borne pathogens Anaplasma phagocytophilum and Ehrlichia chaffeensis.

As emerging tick born rickettsial diseases caused by A. phagocytophilum and E. chaffeensis, anaplasmosis and ehrlichiosis have become a serious threat to human and animal health throughout the world. In particular, in China, an unusual transmission of nosocomial cases of human granulocytic anaplasmosis occurred in Anhui Province in 2006 and more recent coinfection case of A. phagocytophilum and E. chaffeensis was documented in Shandong Province. Although the seroprevalence of human granulocytic anaplasmosis (former human granulocytic ehrlichiosis, HGE) has been documented in several studies, these data existed on local investigations, and also little data was reported on the seroprevalence of human monocytic ehrlichiosis (HME) in China. In this cross-sectional epidemiological study, indirect immunofluorescence antibody assay (IFA) proposed by WHO was used to detect A. phagocytophilum and E. chaffeensis IgG antibodies for 7,322 serum samples from agrarian residents from 9 provinces/cities and 819 urban residents from 2 provinces. Our data showed that farmers were at substantially increased risk of exposure. However, even among urban residents, risk was considerable. Seroprevalence of HGA and HME occurred in diverse regions of the country and tended to be the highest in young adults. Many species of ticks were confirmed carrying A. phagocytophilum organisms in China while several kinds of domestic animals including dog, goats, sheep, cattle, horse, wild rabbit, and some small wild rodents were proposed to be the reservoir hosts of A. phagocytophilum. The broad distribution of vector and hosts of the A. phagocytophilum and E. chaffeensis, especially the relationship between the generalized susceptibility of vectors and reservoirs and the severity of the disease's clinical manifestations and the genetic variation of Chinese HGA isolates in China, is urgently needed to be further investigated.

Rapid, simple and sensitive detection of Q fever by loop-mediated isothermal amplification of the htpAB gene.

BACKGROUND: Q fever is the most widespread zoonosis, and domestic animals are the most common sources of transmission. It is not only difficult to distinguish from other febrile diseases because of the lack of specific clinical manifestations in humans, but it is also difficult to identify the disease in C. burnetii-carrying animals because of the lack of identifiable features. Conventional serodiagnosis requires sera from the acute and convalescent stages of infection, which are unavailable at early diagnosis. Nested PCR and real-time PCR require equipment. In this study, we developed a Loop-Mediated Isothermal Amplification (LAMP) assay to identify C. burnetii rapidly and sensitively. METHODS: A universal LAMP primer set was designed to detect the repeated sequence IS1111a of the htpAB gene of C. burnetii using PrimerExplorer V4 software. The sensitivity of the LAMP assay was evaluated using known quantities of recombined reference plasmids containing the targeted genes. The specificity of the developed LAMP assay was determined using 26 members of order Rickettsiae and 18 other common pathogens. The utility of the LAMP assay was further compared with real time PCR by the examination 24 blood samples including 6 confirmed and 18 probable Q fever cases, which diagnosed by IFA serological assessment and real time PCR. In addition, 126 animal samples from 4 provinces including 97 goats, 7 cattle, 18 horses, 3 marmots and 1 deer were compared by these two methods. RESULTS: The limits of detection of the LAMP assay for the htpAB gene were 1 copy per reaction. The specificity of the LAMP assay was 100%, and no cross-reaction was observed among the bacteria used in the study. The positive rate of unknown febrile patients was 33.3%(95%CI 30.2%-36.4%) for the LAMP assay and 8.3%(95%CI 7.4%-9.2%) for the real time PCR(P<0.05). Similarly, the total positive rate of animals was 7.9%(95%CI 7.1%-8.7%) for the LAMP assay and 0.8%(95%CI 0.7%-0.9%)for the real time PCR(P<0.01). Using the developed LAMP assay, Q fever in the Yi Li area, Xinjiang Province, was confirmed. CONCLUSIONS: The LAMP assay is a potential tool to support the diagnosis of Q fever in humans and domestic animals in the field, especially in the rural areas of China, because of its rapid and sensitive detection without the aid of sophisticated equipment or a complicated protocol.

Anaplasma phagocytophilum infection in domestic animals in ten provinces/cities of China.

A nationwide epidemiologic investigation of domestic animal infections has been conducted in nine provinces and one city during 2007-2010. Serum samples from a total of 707 goats, 433 cattle, and 219 dogs were collected for detecting Anaplasma phagocytophilum IgG antibody by immunofluorescence assays and the average seroprevalences were 10.05% for dogs, 3.82% for goats, and 0.69% for cattle, respectively. A total of 472 goats, 201 cattle, 102 dog blood clots, and 1,580 ticks were collected for polymerase chain reaction (PCR) amplifying A. phagocytophilum 16S rRNA genes and the PCR-positive rates were 26.69% for goats, 23.38% for cattle, and 10.89% for dogs. Six species were identified and the average PCR-positive rates were 58.3% for Dermacentor silvarum, 43.9% for Haemaphysalis longicornis, 12.5% for Ixodes persulcatus, 7.5% (3 of 40) for Boophilus microplus, and 5.2% for Rhipicephalus sanguineus, respectively. The evidence in the study indicated the zoonotic Rickettsia is highly prevalent in China.

A PVP-extract fungal protein of Omphalia lapideacens and its antitumor activity on human gastric tumors and normal cells.

Omphalia lapidescens is an important medicinal fungus as well as traditional Chinese medicine used for disease treatment. It is mainly used as a vermifuge for anthelmintic therapy, but it has not been hitherto reported to possess antitumor activity. In this study, a purified bioactive protein in O. lapidescens (pPeOp) was obtained using polyvinylpyrrolidone (PVP) followed by gel filtration chromatography. To evaluate the in vitro antitumor activity of pPeOp in human gastric tumor cells (MC-4 and SGC-7901) and normal cells (MC-1), MTT assay and FCM assay were used and the morphological changes, cell viability, cell death rate and cell apoptosis rate of MC-4, SGC-7901 and MC-1 cells were estimated. The results showed that pPeOp could significantly reduce the cell viability of MC-4 and SGC-7901 cells in a concentration-dependent manner, with IC50 values of 236.05 and 156.28 µg/ml, respectively. The morphological observation also indicated a similar result. In FCM assays, a significant increase of cell death rate and cell apoptosis rate of the tumor cells were observed, indicating probable necrosis-inducing effects and/or apoptosis-inducing effects of pPeOp. Importantly, there was no significant effect of pPeOp on MC-1 cells in each assay, showing that pPeOp has no adverse effects on the normal cells. In conclusion, pPeOp is a newly discovered bioactive protein in O. lapidescens and this is the first report on antitumor activity of such a fungal protein. This may provide a meaningful basis for developing a new protein drug for treatment against cancer, especially gastric cancer.

[Sero-epidemiologic investigation on tick-borne diseases of humans and domestic animals in Zhejiang province].

OBJECTIVE: To investigate the seroprevalence of tick-borne diseases in humans and domestic animals from rural areas of Zhejiang province. METHODS: Anji county, Jindong district and Tiantai county were selected for samples collection according to their geographic locations and historical prevalence of tick-borne diseases. Blood samples of humans and domestic animals were collected in the three sites. An indirect immuno-fluorescent antibody test was used to determine the presence of IgG antibodies of Rickettsiae heilongjiangii, Orientia tsutsugamushi, R. typhi, Anaplasma phagocytosis, Ehrlichia chaffeensis, Bartonella, R. hainan and Coxiella burnetii in these samples. RESULTS: Six hundred and eighty-three blood samples including 579 from humans and 104 from domestic animals (53 from cattles and 51 from sheep) were collected from the three sites. Antibody positive rates of Orientia tsutsugamushi, R. typhi, Ehrlichia chaffeensis and Coxiella burnetii were significantly different between these sites. IgG from all the 8 pathogens were detected in samples from humans. It was found that the sero-prevalence rates of R. typhi, Bartonella and C. burnetii (20.7%, 10.9%, 5.5%) of adults were higher than those of other Rickettsiae under investigation. The seroprevalence of R. typhi increased along with age. IgG from the 7 pathogens were detected in samples from domestic animals except for Anaplasma phagocytosis. The sero-prevalence rates of R. typhi, Bartonella and R. hainan (69.2%, 51.0%, 22.1%) of adults were higher than those of other Rickettsiae investigated. CONCLUSION: Tick-borne diseases did spread widely in humans and domestic animals from different rural areas of Zhejiang province. The sero-prevalence rates of R. typhi, B. henselae, R. hainan and C. burnetii were higher than that from other pathogens.

[Detection of co-infection with Lyme spirochetes and Spotted fever group rickettsiae in a group of Haemaphysalis longicornis].

OBJECTIVE: The present study was conducted to investigate the infection of Lyme disease, Spotted fever, Ehrlichiosis (anaplasmosisin) in wild animals and ticks in the mountain areas of Zhejiang province. METHODS: Nested polymerase chain reaction was used to amplify specific DNA sequences of Lyme spirochetes, Spotted fever group rickettsiae, Ehrlichia(anaplasma) from samples of mice and ticks. RESULTS: 14 positive samples were identified from 121 mice and 105 groups of ticks. Among mice samples, one positive 5S-23S rDNA intergenic spacer of Borrelia burgdorferi and two 5' fragments of Ehrlichia (anaplasma) 16S rDNA were obtained. 11 positive results were detected from tick samples including three 5S-23S rDNA intergenic spacer regions of Borrelia burgdorferi and eight 5' fragments of Spotted fever group rickettsiae outer member protein A gene. One group of adult ticks, Haemaphysalis longicornis, which had been collected from eastern mountain area were detected to have co-infected with Lyme spirochetes and Spotted fever group rickettsiae. The positive sequences of 5S-23S rDNA intergenic spacer and ompA gene were tested and analyzed as Lyme spirochetes while rickettsia which was closely related to Borrelia valaisiana and R. massiliae. CONCLUSION: This was the first report about co-infection of Lyme spirochetes and Spotted fever group rickettsiae found in the same group of adult Haemaphysalis longicornis. It is very important to strengthen the surveillance program on tick-borne infectious disease and their pathogenic in vectors, wild animals and targeted high risk groups and to differentiate the clinical manifestation and diagnosis to extend the knowledge of tick-borne infectious diseases in Zhejiang.

[Molecular characterization and sequence comparison of the M and S segments of Hantavirus ZJ5 strain].

OBJECTIVE: In order to understand the molecular characters of Hantavirus ZJ5 strain, its complete M and S genome were sequenced and compared with that of other hantavirus strains. METHODS: We prepared the total RNA from ZJ5. Infected cells and the raw or purified RT-PCR product was cloned and sequenced. RESULTS: With sequence compation, we found ZJ5 strain complete M and S segment had higher homology with SEO-type strains than other type of HV, but differential genes were 11.7%-19.2% and 6.7%-14.5% from SEOV. The phylogenetic trees constructed by complete M ind S segment showed that ZJ5 strain was located in SEOV group, and structured alone embranchment. CONCLUSION: The ZJ5 strain was believed to belong to SEO-type virus,and suggest that ZJ5 strain is a new subtype S SEOV group,and structured alone embranchment. CONCLUSION: The ZJ5 strain was believed to belong to SEO-type virus, and suggest that ZJ5 strain is a new subtype from other SEO viruses.

[Study on the recombinant expression of Hantaan virus protein N and the establishment and application of rNP-IgM direct capture ELISA].

OBJECTIVE: To clone the gene encoding nucleocapsid protein (NP) of hantavirus strain Z10 (HV-Z10), to construct its prokaryotic expression system as well as to establish a rNP-IgM direct capture ELISA based on HRP-labeled recombinant NP (rNP), in order to detect serum samples of patients suffering from hemorrhagic fever with renal syndrome (HFRS) and to evaluate the effects of detection. METHODS: Gene encoding NP of strain HV-Z10 was amplified by PCR and then its prokaryotic expression system pET28a-Z10N-E. coli BL21DE3 was constructed, using routine genetic engineering method. SDS-PAGE was applied to measure the expression of rNP and ion-exchange plus Ni-NTA-affinity chromatography was performed to purify the recombinant product. Western blot assay was used to determine the specific immuno-reactivity of rNP while HRP-labeled rNP-IgM direct capture ELISA was established to detect the serum samples from 95 cases of confirmed HFRS patients. The detection effect was compared with that by routine HV-IgM indirect capture ELISA method. RESULTS: pET28a-Z10N-E. coli BL21DE3 was able to express rNP with high efficiency. The purified rNP only showed a single protein fragment in the gel after SDS-PAGE. HV-IgG could efficiently recognize rNP and hybridize with the recombinant protein. 94.73% (90/95) of HFRS patients' serum samples were positively confirmed by rNP-IgM direct capture ELISA, while a positive rate of 92.63% (88/95) in the same samples was confirmed by HV-IgM indirect capture ELISA. The distributions of A450 values of the serum samples detected by the two IgM capture ELISAs as well as the changes of the A450 mean values from several serum samples with different dilutions were similar. CONCLUSION: We successfully constructed a high efficient prokaryotic expression system of NP encoding gene of hantavirus strain HV-Z10. The rNP-IgM direct capture ELISA that established in this study could be used as a new serological test for HFRS diagnosis because of its simplicity, safety, with high sensitivity and specificity.