Description of Candidatus Bartonella fadhilae n. sp. and Candidatus Bartonella sanaae n. sp. (Bartonellaceae) from Dipodillus dasyurus and Sekeetamys calurus (Gerbillinae) from the Sinai Massif (Egypt)

Geographical distribution of Bartonella spp in the countries of the WHO Eastern Mediterranean Region (WHO-EMRO)

Bartonellosis is a vector-borne and zoonotic diseases in humans, especially in immunocompromised individuals. However, there is no complete data about the geographical distribution of different species of Bartonella, as well as the status of its reservoirs, vectors, and human cases in most parts of the world. In this study, published reports related to Bartonella species from WHO-EMRO region countries were searched in different databases until October 2023. The eighteens different species of Bartonella were reported in WHO-EMRO countries including Bartonella henselae, Bartonella quintana, Bartonella elizabethae, Bartonella bovis, Bartonella clarridgeiae, Bartonella vinsonii, Bartonella doshiae, Bartonella taylorii, Bartonella rochalimae, Bartonella tribocorum, Bartonella rattimassiliensis, candidatus Bartonella merieuxii, candidatus Bartonella dromedarii, Bartonella acomydis, Bartonella jaculi, Bartonella coopersplainsensis and Bartonella koehlerae. Also, only human cases of B. henselae and B. quintana infections were reported from WHO-EMRO countries. The infections of Bartonella are important in the WHO-EMRO region, but they have been neglected by clinicians and healthcare systems.

Tick-borne diseases in Egypt: A one health perspective

Background

Ticks are important arthropod vectors that transmit pathogens to humans and animals. Owing to favourable climatic and environmental conditions, along with animal importation from neighbouring countries, ticks and tick-borne diseases (TBDs) are widespread in Egyptian localities. Here, we review the current knowledge on the epidemiology of TBDs in Egypt in light of the One Health paradigm.

Methods and results

Five scientific databases, including "Web of Science", "Scopus", "PubMed", "Science Direct", and "Google Scholar", were searched for articles describing TBDs in Egypt. A total of 18 TBDs have been reported in humans and animals, including three protozoal diseases (babesiosis, theileriosis, and hepatozoonosis), 12 bacterial diseases (anaplasmosis, ehrlichiosis, Lyme borreliosis, bovine borreliosis, tick-borne relapsing fever, Mediterranean spotted fever, African tick-borne fever, lymphangitis-associated rickettsiosis, bartonellosis, tularaemia, Q fever, and aegyptianellosis), and three viral diseases (Crimean-Congo haemorrhagic fever, Alkhurma haemorrhagic fever, and Lumpy skin disease).

Conclusions

Despite the circulation of zoonotic tick-borne pathogens among livestock and tick vectors, human infections have been overlooked and are potentially limited to infer the actual communicable disease burden. Therefore, facility-based surveillance of TBDs, combined with capacity building for laboratory diagnostics in healthcare facilities, is urgently required to improve diagnosis and inform policy-making in disease prevention. Additionally, collaboration between expert researchers from various disciplines (physicians, biologists, acarologists, and veterinarians) is required to develop advanced research projects to control ticks and TBDs. Considering that domestic livestock is integral to many Egyptian households, comprehensive epidemiological studies on TBDs should assess all disease contributors, including vertebrate hosts (animals, humans, and rodents) and ticks in the same ecological region, for better assessment of disease burden. Additionally, upscaling of border inspections of imported animals is required to stop crossover movements of ticks and TBDs.

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.

In-Depth Investigation of the Safety of Wooden Shelves Used for Traditional Cheese Ripening

The main goal of this research was to characterize the bacterial diversity of the wooden boards used for aging traditional Sicilian cheeses and to evaluate whether pathogenic bacteria are associated with these surfaces. Eighteen cheese dairy factories producing three traditional cheese typologies (PDO Pecorino Siciliano, PDO Piacentinu Ennese, and Caciocavallo Palermitano) were selected within the region of Sicily. The wooden shelf surfaces were sampled by a destructive method to detach wood splinters as well as by a nondestructive brushing to collect microbial cells. Scanning electron microscopy showed the presence of almost continuous bacterial formations on the majority of the shelves analyzed. Yeasts and fungal hyphae were also visualized, indicating the complexity of the plank communities. The amplicon library of the 16S rRNA gene V3-V4 region was paired-end sequenced using the Illumina MiSeq system, allowing the identification of 14 phyla, 32 classes, 52 orders, 93 families, and 137 genera. Staphylococcus equorum was identified from all wooden surfaces, with a maximum abundance of 64.75%. Among cheese-surface-ripening bacteria, Brevibacterium and Corynebacterium were detected in almost all samples. Several halophilic (Halomonas, Tetragenococcus halophilus, Chromohalobacter, Salimicrobium, Marinococcus, Salegentibacter, Haererehalobacter, Marinobacter, and Idiomarinaceae) and moderately halophilic (Salinicoccus, Psychrobacter, and Salinisphaera) bacteria were frequently identified. Lactic acid bacteria (LAB) were present at low percentages in the genera Leuconostoc, Lactococcus, Lactobacillus, Pediococcus, and Streptococcus. The levels of viable microorganisms on the wooden shelves ranged between 2.4 and 7.8 log CFU/cm2. In some cases, LAB were counted at very high levels (8.2 log CFU/cm2). Members of the Enterobacteriaceae family were detected in a viable state for only six samples. Coagulase-positive staphylococci, Salmonella spp., and Listeria monocytogenes were not detected. Seventy-five strains belonged to the genera Leuconostoc, Lactococcus, Pediococcus, Enterococcus, Lactobacillus, and Weissella. IMPORTANCE This study provides evidence for the lack of pathogenic bacteria on the wooden shelves used to ripen internal bacterially ripened semihard and hard cheeses produced in Sicily. These three cheeses are not inoculated on their surfaces, and surface ripening is not considered to occur or, at least, does not occur at the same extent as surface-inoculated smear cheeses. Several bacterial groups identified from the wooden shelves are typically associated with smear cheeses, strongly suggesting that PDO Pecorino Siciliano, PDO Piacentinu Ennese, and Caciocavallo Palermitano cheese rind contributes to their final organoleptic profiles.

Molecular epidemiology of certain vector-borne bacterial microorganisms in domestic animals and their ectoparasites in Egypt

Vector-borne bacterial diseases (VBBD) are a diverse group of tropical and subtropical zoonotic diseases. This study investigated the possibility of domestic animals to carry certain vector-borne bacterial microorganisms (VBBMs), as well as the presence of these targeted DNAs in their ectoparasites in different localities of Egypt using molecular analyses. For this study, 234 animal hosts (112 cattle, 38 sheep, 28 goats, 26 buffaloes, 22 donkeys, and 8 horses) in addition to 115 ectoparasites (95 ticks and 20 lice) were investigated for the molecular detection of Bartonella spp., Borrelia spp., and Rickettsia spp., targeting 16S-23S rRNAITS, 16S rRNA, and gltA genes, respectively. The results indicated that the overall prevalence of VBBD was observed in 17 animals (7.26%), of which 16 (6.84%) were positive for Bartonella spp. and one (0.43%) was positive for Borrelia theileri. All blood samples were negative for the DNA of Rickettsia spp. In addition, the results demonstrated that all ectoparasites were free from VBBDNA. Furthermore, of the animals examined for ectoparasite infestation, 28 (11.97%) and 5 (2.14%) represented Rhipicephalus annulatus ticks and Haematopinus tuberculatus lice, respectively, which infested animals. Analysis of epidemiological factors revealed that gender, age, and ectoparasitic infestation of animals had a significant effect on Bartonella infection, whereas no significant difference between animal species was observed. Hence, we report a potential novel Bartonella sp. from cattle and buffaloes, including a new genotype of Bo. theileri from cattle, in Egypt.

Lists of names of prokaryotic Candidatus taxa

We here present annotated lists of names of Candidatus taxa of prokaryotes with ranks between subspecies and class, proposed between the mid-1990s, when the provisional status of Candidatus taxa was first established, and the end of 2018. Where necessary, corrected names are proposed that comply with the current provisions of the International Code of Nomenclature of Prokaryotes and its Orthography appendix. These lists, as well as updated lists of newly published names of Candidatus taxa with additions and corrections to the current lists to be published periodically in the International Journal of Systematic and Evolutionary Microbiology, may serve as the basis for the valid publication of the Candidatus names if and when the current proposals to expand the type material for naming of prokaryotes to also include gene sequences of yet-uncultivated taxa is accepted by the International Committee on Systematics of Prokaryotes.

Molecular detection and characterization of Bartonella spp. in pet cats and dogs in Shenzhen, China

Bartonella spp. are emerging vector-borne pathogens distributed worldwide that can infect humans and a wide range of mammals including small companion animals (cats and dogs). An increasing number of studies from the worldwide have reported cat and dog Bartonella infections in recently years. Cats and dogs are the primary reservoir or accidental hosts for Bartonella henselae, the main causal agent of human cat scratch disease. Since pet cat and dog sharing human living environment and have the direct and intimate contact with humans, pet cats and dogs may represent excellent epidemiological sentinels for Bartonella infection in humans. In this study, 475 blood samples were collected from pet cats and dogs in local animal hospitals located at five districts of Shenzhen City, and detected the presence of Bartonella. Bartonella DNA was detected in eight samples collected from pet cats, no positive sample was detected from pet dog samples. Sequence comparison and phylogenetic analysis revealed that the eight sequences of Bartonella identified here shared the highest identity with B. henselae. Given the intimate contact between pet animals and humans, many attentions should be paid to prevent the Bartonella infections originate from pet cats or dogs, although the Bartonella infection rate in pet cats and dogs might be rather low.

Fleas of black rats (Rattus rattus) as reservoir host of Bartonella spp. in Chile

Background

Rattus rattus is a widely distributed, invasive species that presents an important role in disease transmission, either directly or through vector arthropods such as fleas. These black rats can transmit a wide variety of pathogens, including bacteria of the genus Bartonella, which can cause diseases in humans and animals. In Chile, no data are available identifying fleas from synanthropic rodents as Bartonella vectors. The aim of this study was to investigate the prevalence of Bartonella spp. in the fleas of R. rattus in areas with different climate conditions and featuring different human population densities.

Methods

In all, 174 fleas collected from 261 R. rattus captured from 30 localities with different human densities (cities, villages, and wild areas) across five hydrographic zones of Chile (hyper-arid, arid, semi-arid, sub-humid, and hyper-humid) were examined. Bartonella spp. presence was determined through polymerase chain reaction, using gltA and rpoB genes, which were concatenated to perform a similarity analysis with BLAST and phylogenetic analysis.

Results

Overall, 15 fleas species were identified; Bartonella gltA and rpoB fragments were detected in 21.2% (37/174) and 19.5% (34/174) of fleas, respectively. A total of 10 of the 15 fleas species found were positive for Bartonella DNA. Leptopsylla segnis was the most commonly collected flea species (n = 55), and it also presented a high prevalence of Bartonella DNA (P% = 34.5%). The highest numbers of fleas of this species were collected in villages of the arid zone. There were no seasonal differences in the prevalence of Bartonella DNA. The presence of Bartonella DNA in fleas was recorded in all hydrographic areas, and the arid zone presented the highest prevalence of this species. Regarding areas with different human densities, the highest prevalence was noted in the villages (34.8% gltA and 31.8% rpoB), followed by cities (14.8% gltA and 11.1% rpoB) and wild areas (7.4% gltA and 14.8% rpoB). The BLAST analysis showed a high similitude (>96%) with four uncharacterized Bartonella genotypes and with two species with zoonotic potential: B. mastomydis and B. tribocorum. The phylogenetic analysis showed a close relationship with B. elizabethae and B. tribocorum. This is the first study to provide evidence of the presence of Bartonella in fleas of R. rattus in Chile, indicating that the villages and arid zone correspond to areas with higher infection risk.

Bartonella infections in cats and dogs including zoonotic aspects

Bartonellosis is a vector-borne zoonotic disease with worldwide distribution that can infect humans and a large number of mammals including small companion animals (cats and dogs). In recent years, an increasing number of studies from around the world have reported Bartonella infections, although publications have predominantly focused on the North American perspective. Currently, clinico-pathological data from Europe are more limited, suggesting that bartonellosis may be an infrequent or underdiagnosed infectious disease in cats and dogs. Research is needed to confirm or exclude Bartonella infection as a cause of a spectrum of feline and canine diseases. Bartonella spp. can cause acute or chronic infections in cats, dogs and humans. On a comparative medical basis, different clinical manifestations, such as periods of intermittent fever, granulomatous inflammation involving the heart, liver, lymph nodes and other tissues, endocarditis, bacillary angiomatosis, peliosis hepatis, uveitis and vasoproliferative tumors have been reported in cats, dogs and humans. The purpose of this review is to provide an update and European perspective on Bartonella infections in cats and dogs, including clinical, diagnostic, epidemiological, pathological, treatment and zoonotic aspects.

Bartonella infections in three species of Microtus: prevalence and genetic diversity, vertical transmission and the effect of concurrent Babesia microti infection on its success

BACKGROUND

Bartonella spp. cause persistent bacterial infections in mammals. Although these bacteria are transmitted by blood-feeding arthropods, there is also evidence for vertical transmission in their mammalian hosts. We aimed to determine: (i) the prevalence and diversity of Bartonella spp. in a Microtus spp. community; (ii) whether vertical transmission occurs from infected female voles to their offspring; (iii) the effect of concurrent Babesia microti infection on the success of vertical transmission of Bartonella; and (iv) the impact of congenital infection on pup survival.

RESULTS

We sampled 124 Microtus arvalis, 76 Microtus oeconomus and 17 Microtus agrestis. In total, 115 embryos were isolated from 21 pregnant females. In the following year 11 pregnant females were kept until they had given birth and weaned their pups (n = 62). Blood smears and PCR targeting the Bartonella-specific rpoB gene fragment (333bp) were used for the detection of Bartonella. Bartonella DNA was detected in 66.8% (145/217) of the wild-caught voles. Bartonella infection was detected in 81.8% (36/44) of pregnant female voles. Bartonella-positive individuals were identified among the embryos (47.1%; 40/85) and in 54.8% (34/62) of pups. Congenitally acquired Bartonella infections and co-infection with B. microti had no impact on the survival of pups over a 3-week period post partum. Among 113 Bartonella sequences, four species were detected: Bartonella taylorii, Bartonella grahamii, Bartonella doshiae and a Bartonella rochalimae-like genotype. Bartonella taylorii clade B was the dominant species in wild-caught voles (49%), pregnant females (47%), their embryos (85%), dams (75%) and pups (95%).

CONCLUSIONS

High prevalence of Bartonella spp. infection maintained in Microtus spp. community is followed by a high rate of vertical transmission of several rodent species of Bartonella in three species of naturally infected voles, M. arvalis, M. oeconomus and M. agrestis. Congenitally acquired Bartonella infection does not affect the survival of pups. Co-infection with B. microti does not affect the effectiveness of the vertical transmission of Bartonella in voles. Bartonella taylorii clade B was found to be the dominant species in wild-caught voles, including pregnant females and dams, and in their offspring, and was also found to be the most successful in vertical transmission.

Molecular assessment of Bartonella in Gerbillus nanus from Saudi Arabia reveals high levels of prevalence, diversity and co-infection

Bartonellae bacteria are associated with several re-emerging human diseases. These vector-borne pathogens have a global distribution, yet data on Bartonella prevalence and diversity in the Arabian Peninsula are limited. In this study we assessed the Bartonella infection status of the Baluchistan gerbil (Gerbillus nanus), a species associated with pastoral communities throughout the Middle East region, using a multi-gene PCR screening approach. The results demonstrated that 94 (68.1%) of the 138 gerbils trapped on a monthly basis, over a period of one year, were PCR-positive. Sequencing of the gltA gene region confirmed the presence of four discrete Bartonella lineages (I-IV) and high levels of co-infection (33.0%). Each of the four lineages, varied in overall abundance (7.5%-47.9%) and had discernible seasonal peaks. Bartonella status was significantly correlated with ectoparasite presence, but not with sex, nor with season. Statistical analyses further revealed that co-infected individuals had a significantly higher relative body condition. Multi-locus sequence analysis (MLSA) performed with a concatenated dataset of three genetic loci (gltA, nuoG, and rpoB), 1452 nucleotides (nt) in length confirmed that lineage IV, which occurred in 24 PCR-positive animals (25.5%), is most closely related to zoonotic B. elizabethae. The remaining three lineages (I-III) formed a monophyletic clade which, on the basis of gltA was shown to contain bartonellae from diverse Gerbillinae species from the Middle East, suggestive of a gerbil-associated species complex in this region. Lineage I was identical to a Candidatus B. sanaae strain identified previously in Bushy-tailed jirds (Sekeetamys calurus) from Egypt, wherease MLSA indicate that lineages II and III are novel. The high levels of infection and co-infection, together with the presence of multiple Bartonella lineages indicate that Gerbillus nanus is likely a natural reservoir of Bartonella in the Arabian Peninsula.