Molecular Detection of Bartonella spp. in Rodents in Chernobyl Exclusion Zone, Ukraine

Rodriguez-Morales A, Furqan Ilyas M, Santos Ferreira MDN, Singh Malik Y, Kalantari R, Shahrokhabadi A, Jafari N, Shahabinejad F, Maleki Y, Montajeb S, Mehrpouya R, Ahmadi H, Vazir B, Kabir F, Rehman A, Elmi Z, Hajipour P, El-Seedi HR, Eisenreich W, Shehata AA. Migratory Wave due to Conflicts: Risk of Increased Infection From Zoonotic Diseases

Wars have devastating effects on all the components of the One Health approach: humans, animals, and ecosystems. Wars and the resulting migratory waves massively disrupt normal animal health services and surveillance. Among other consequences, they adversely impact the early detection, prevention, and control of animal diseases. Uncontrolled movement of animals or their undisposed carcasses, the destruction of wildlife habitats, and the increased interface between humans, wildlife, and domestic animals contribute to uncontrolled transmission and spread of zoonotic pathogens from animals to humans. In the last millennium, zoonotic diseases such as the "Black Death" were triggered by devastating wars and led to the deaths of a large fraction of the human population. However, also recent and ongoing wars carry the risk of an uncontrollable increase in zoonotic diseases. The most significant zoonotic diseases reported during the recent wars are African swine fever, highly pathogenic avian influenza, rabies, leptospirosis, and brucellosis, as well as foodborne and waterborne zoonotic diseases. Indeed, alarming rates of infections by antimicrobial-resistant pathogens such as Mycobacterium tuberculosis go along with wars, as seen in the current Ukraine-Russia conflict. Considering human migration, foodborne and waterborne zoonotic diseases are key health threats for refugees due to the consumption of unsafe food, lack of safe water, and disruption of the water supply and sanitation system. This review summarizes the potential factors and some data associated with the increased risk of zoonotic disease emergence and transmission during recent and ongoing conflicts.

Small mammals as hosts of vector-borne pathogens in the High Tatra Mountains region in Slovakia, Central Europe

Rodents and insectivores are significant reservoirs of many zoonotic pathogens, contributing to the transmission of diseases affecting human and animal health. This study investigated the prevalence and diversity of vector-borne pathogens in small mammals within the High Tatras region of Slovakia, an area with substantial recreational activity and protected zones. A total of 156 small mammals, comprising ten species, were screened for pathogens such as Bartonella spp., Borrelia spp., Anaplasma phagocytophilum, and Babesia spp. The prevalence of vector-borne pathogens in the studied animals reached 74.35%, with Bartonella spp. being the most common, identified in 57.7% of the animals, particularly in Apodemus flavicollis and Clethrionomys glareolus. Borrelia burgdorferi (sensu lato) was detected in 11.5% of the rodents, with Borrelia afzelii identified as the predominant species. Babesia microti was found in A. flavicollis and Mus musculus, with a total prevalence of 3.2%. The lowest was the prevalence of A. phagocytophilum reaching 1.9%. This study provides evidence of the significant role of rodents as reservoirs of vector-borne pathogens in protected areas of the High Tatras region and Tatra National Park.

Molecular epidemiology of Bartonella species from sympatric mammals collected in urban and rural areas of Punjab, Pakistan

Bartonella can infect a variety of mammals including humans and has been detected in the Americas, Europe, Africa, and Asia. Roughly two-thirds of identified Bartonella species are found and maintained in rodent reservoirs, with some of these species linked to human infections. Rodents (N=236) were caught from the Sahiwal division of Punjab, Pakistan and tested for Bartonella using PCR targeting gltA and rpoB genes, followed by sequencing of rpoB-positive samples. Genetic relatedness to other published Bartonella spp. rpoB gene sequences were examined using BLAST and phylogenetic analysis. Overall, 7.62% (18/236) of rodents were positive for both gltA and rpoB fragments. Rattus rattus and R. norvegicus had 7.94% (12/151) and 7.05% (6/85) positivity rates for Bartonella DNA, respectively. Phylogenetic analysis revealed a close relatedness between Bartonella spp. from Pakistan to Bartonella spp. from China, Nepal, and Malaysia. This study is the first reported detection of Bartonella spp. in R. rattus and R. norvegicus from the Sahiwal area of Punjab, Pakistan.

Epidemiology and Genetic Diversity of Bartonella in Rodents in Urban Areas of Guangzhou, Southern China

Bartonella spp. are gram-negative bacteria that can infect a wide spectrum of mammals. Rodents are considered to be the natural reservoir of many Bartonella species that are transmitted by various blood-sucking arthropods. The close contact between rodents and humans in urban areas increased the chance of transmitting rodent-borne Bartonella to humans. Investigation of the epidemiological characteristics of Bartonella infection in rodents is of great significance for the prevention and control of human Bartonellosis. In this study, rodents were captured to monitor the prevalence of Bartonella in urban areas of Guangzhou city. Six official or candidate species of Bartonella, including two confirmed zoonotic species, were detected with an overall prevalence of 6.4% in rodents captured herein. In addition, Rattus norvegicus was the predominant host species for Bartonella infection, and B. queenslandensis was the dominant species circulating in rodents in these areas. These results provide insights into the prevalence and genetic diversity of Bartonella species circulating in rodents in the urban areas of Guangzhou, and also urged the surveillance of rodent-associated Bartonella species in these areas.

Emerging rodent-associated Bartonella: a threat for human health?

Background

Species of the genus Bartonella are facultative intracellular alphaproteobacteria with zoonotic potential. Bartonella infections in humans range from mild with unspecific symptoms to life threatening, and can be transmitted via arthropod vectors or through direct contact with infected hosts, although the latter mode of transmission is rare. Among the small mammals that harbour Bartonella spp., rodents are the most speciose group and harbour the highest diversity of these parasites. Human–rodent interactions are not unlikely as many rodent species live in proximity to humans. However, a surprisingly low number of clinical cases of bartonellosis related to rodent-associated Bartonella spp. have thus far been recorded in humans.

Methods

The main purpose of this review is to determine explanatory factors for this unexpected finding, by taking a closer look at published clinical cases of bartonellosis connected with rodent-associated Bartonella species, some of which have been newly described in recent years. Thus, another focus of this review are these recently proposed species.

Conclusions

Worldwide, only 24 cases of bartonellosis caused by rodent-associated bartonellae have been reported in humans. Possible reasons for this low number of cases in comparison to the high prevalences of Bartonella in small mammal species are (i) a lack of awareness amongst physicians of Bartonella infections in humans in general, and especially those caused by rodent-associated bartonellae; and (ii) a frequent lack of the sophisticated equipment required for the confirmation of Bartonella infections in laboratories that undertake routine diagnostic testing. As regards recently described Bartonella spp., there are presently 14 rodent-associated Candidatus taxa. In contrast to species which have been taxonomically classified, there is no official process for the review of proposed Candidatus species and their names before they are published. This had led to the use of malformed names that are not based on the International Code of Nomenclature of Prokaryotes. Researchers are thus encouraged to propose Candidatus names to the International Committee on Systematics of Prokaryotes for approval before publishing them, and only to propose new species of Bartonella when the relevant datasets allow them to be clearly differentiated from known species and subspecies.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-022-05162-5.

Biomolecular Investigation of Bartonella spp. in Wild Rodents of Two Swiss Regions

Rodents represent a natural reservoir of several Bartonella species, including zoonotic ones. In this study, small wild rodents, collected from two sites in rural areas of Switzerland, were screened for Bartonella spp. using molecular detection methods. In brief, 346 rodents were trapped in two rural sites in the Gantrisch Nature Park of Switzerland (Plasselb, canton of Fribourg, and Riggisberg, canton of Bern). Pools of DNA originating from three animals were tested through a qPCR screening and an end-point PCR, amplifying the 16S-23S rRNA gene intergenic transcribed spacer region and citrate synthase (gltA) loci, respectively. Subsequently, DNA was extracted from spleen samples belonging to single animals of gltA positive pools, and gltA and RNA polymerase subunit beta (rpoB) were detected by end-point PCR. Based on PCR results and sequencing, the prevalence of infection with Bartonella spp. in captured rodents, was 21.10% (73/346): 31.78% in Apodemus sp. (41/129), 10.47% in Arvicola scherman (9/86), 17.05% in Myodes glareolus (22/129), and 50% in Microtus agrestis (1/2). A significant association was observed between Bartonella spp. infection and rodent species (p < 0.01) and between trapping regions and positivity to Bartonella spp. infection (p < 0.001). Similarly, prevalence of Bartonella DNA was higher (p < 0.001) in rodents trapped in woodland areas (66/257, 25.68%) compared to those captured in open fields (9/89, 10.11%). Sequencing and phylogenetic analysis demonstrated that the extracted Bartonella DNA belonged mainly to B. taylorii and also to Candidatus “Bartonella rudakovii”, B. grahamii, B. doshiae, and B. birtlesii. In conclusion, the present study could rise public health issues regarding Bartonella infection in rodents in Switzerland.