Detection and distribution of zoonotic pathogens in wild Norway rats (Rattus norvegicus) from Tehran, Iran

Intestinal Colonization by Campylobacter jejuni, Clostridium difficile, and Clostridium perfringens among Commensal Rattus norvegicus in the Urban Areas of Tehran, Iran

Background

Rattus norvegicus (R. norvegicus) population plays a significant role in the spread of numerous diseases in urban environments. The present study is aimed at investigating the presence of Campylobacter jejuni (C. jejuni), C. coli, Clostridium difficile (C. difficile), C. difficile toxigenic, and C. perfringens in R. norvegicus captured from urban areas of Tehran, Iran.

Methods

From October 2021 to October 2022, 100 urban rats were trapped in 5 different districts of Tehran, Iran. The genomic DNA was extracted from fecal samples, and the presence of C. jejuni, C. coli, C. perfringens, and C. difficile species was evaluated using PCR assay. Moreover, PCR was used to assess the toxicity of C. difficile isolates.

Results

Overall, 30% (n = 30/100) of fecal samples were positive for zoonotic pathogens. Based on the PCR on hippuricase (hipO), glycine (gly), CIDIF, and phospholipase C (plc) genes, C. perfringens and C. difficile were isolated from 18.2% (n = 14/77) and 5.2% (n = 4/77) of male rats. The highest frequency of C. perfringens and C. jejuni was 25% (n = 5/20) related to the south of Tehran. Toxigenic C. difficile was not detected in all regions.

Conclusion

According to the findings, rats are the main reservoirs for diseases. Therefore, rodent control coupled with the implementation of surveillance systems should be prioritized for urban health.

Detection of Yersinia enterocolitica, Shigella spp. and Salmonella spp. in Rattus norvegicus captured from Tehran, Iran

Background: The present study aims to determine the presence of Yersinia spp., Yersinia pestis, Yersinia enterocolitica pathogen, Listeria monocytogenes, Salmonella spp., Shigella spp., Francisella tularensis and Borrelia spp. in brown rats of Tehran, Iran. Methods: PCR was used to detect various bacteria in 100 brown rats, Also, ELISA was used to detect antibodies against the F. tularensis and Borrelia spp. Results: A total of 16% and 13% of fecal samples were positive for Yersinia spp. and Y. enterocolitica pathogen. ELISA results were negative for F. tularensis and Borrelia. No specific antibodies (IgG) were against these bacteria. Conclusion: According to the results of our analysis, rats are significant transmitters and carriers of a variety of illnesses that can spread to both people and other animals.

Infections and Influencing Factors of Pathogens in Rattus norvegicus along the Zengjiang River in Guangzhou, China

Background: Rattus norvegicus can carry and transmit various zoonotic pathogens. Some studies were conducted to investigate a few zoonotic pathogens in Guangzhou, China, but no coinfections were investigated or specifically mentioned. Studies on the infections and the influencing factors of various zoonotic pathogens in R. norvegicus along the Zengjiang River in Guangzhou have not been carried out. Materials and Methods: In this study, R. norvegicus was captured in November 2020 and September 2021 along the Zengjiang River, and was tested for Bartonella spp., Leptospira spp., Orientia tsutsugamushi, Borrelia burgdorferi, Hantavirus (HV), Ehrlichia spp., and severe fever with thrombocytopenia syndrome virus (SFTSV) by the RT-PCR. Logistic regression analysis was used to determine the impact of habitat and demographic factors on the infections and coinfections of the surveyed pathogens. Results: In 119 R. norvegicus, the detection rates of Bartonella spp., Leptospira spp., O. tsutsugamushi, B. burgdorferi, and HV were 46.2%, 31.9%, 5%, 0.8%, and 18.5%, respectively. Ehrlichia spp. and SFTSV were negative. The triple coinfection rate of Bartonella spp., Leptospira spp., and HV was 11.8%. In addition, the coinfection of Bartonella spp., Leptospira spp., and B. burgdorferi was 0.8%. Dual coinfection of Bartonella spp. and Leptospira spp., Leptospira spp. and HV, Bartonella spp. and O. tsutsugamushi, Leptospira spp. and O. tsutsugamushi, and HV and O. tsutsugamushi was 9.2%, 3.4%, 1.7%, 1.7%, and 0.8%, respectively. Infections of these pathogens in R. norvegicus were found in habitats of banana plantation, grassland, and bush. Weight affected the infection of Bartonella spp., Leptospira spp., or HV in R. norvegicus. Conclusions: R. norvegicus along the Zengjiang River not only carried various potentially zoonotic pathogens but also had a variety of coinfections. Surveillance of the density and pathogens in R. norvegicus should be strengthened to reduce the incidence of relevant zoonotic diseases.

Investigation of Rickettsia conorii in Patients Suspected of Having Crimean-Congo Hemorrhagic Fever

Rickettsia conorii is the causative agent of Mediterranean spotted fever (MSF). Misdiagnosis of MSF may occur with febrile syndromes associated with rash and thrombocytopenia, such as Crimean-Congo hemorrhagic fever (CCHF). This study aimed to determine the prevalence of R. conorii among serum samples obtained from 260 suspected CCHF patients with features of MSF in Iran (2018–2020). The quantitative polymerase chain reaction (qPCR) method detected three (1.15%) positive 16S rDNA Rickettsia spp. samples that were classified as R. conorii subsp. conorii, R. conorii subsp. Israelensis, and R. helvetica using the sequencing of gltA, ompA, and 17kDa genes. Furthermore, R. conorii IgM antibodies presented in 38 (14.62%) patients by the enzyme-linked immunosorbent assay (ELISA) method. Out of 97 MSF patients with available paired serum samples, IgM seroconversion and a four-fold increase were observed in 14 (14.43%) and 12 (12.37%) patients, respectively. We concluded that rickettsial agents are present in Iran and may be misdiagnosed with other febrile syndromes.