Isolation of Bartonella species from rodents in Taiwan including a strain closely related to 'Bartonella rochalimae' from Rattus norvegicus

An increasing number of Bartonella species originally isolated from small mammals have been identified as emerging human pathogens. During an investigation of Bartonella infection in rodent populations carried out in Taiwan in 2006, a total of 58 rodents were tested. It was determined that 10.3% (6/58) of the animals were Bartonella bacteraemic. After PCR/RFLP analysis, four isolates were identified as Bartonella elizabethae and one isolate as Bartonella tribocorum. However, there was one specific isolate with an unrecognized PCR/RFLP pattern. After further sequence and phylogenetic analyses of the gltA, ftsZ and rpoB genes, and the 16S-23S rRNA intergenic spacer region, the results indicated that this specific isolate from Rattus norvegicus was closely related to human pathogenic 'Bartonella rochalimae'. Further studies need to be conducted to evaluate whether this rodent species could be a reservoir for 'B. rochalimae'

Evolutionary Dynamics of Pathoadaptation Revealed by Three Independent Acquisitions of the VirB/D4 Type IV Secretion System in Bartonella.

The α-proteobacterial genus Bartonella comprises a group of ubiquitous mammalian pathogens that are studied as a model for the evolution of bacterial pathogenesis. Vast abundance of two particular phylogenetic lineages of Bartonella had been linked to enhanced host adaptability enabled by lineage-specific acquisition of a VirB/D4 type IV secretion system (T4SS) and parallel evolution of complex effector repertoires. However, the limited availability of genome sequences from one of those lineages as well as other, remote branches of Bartonella has so far hampered comprehensive understanding of how the VirB/D4 T4SS and its effectors called Beps have shaped Bartonella evolution. Here, we report the discovery of a third repertoire of Beps associated with the VirB/D4 T4SS of B. ancashensis, a novel human pathogen that lacks any signs of host adaptability and is only distantly related to the two species-rich lineages encoding a VirB/D4 T4SS. Furthermore, sequencing of ten new Bartonella isolates from under-sampled lineages enabled combined in silico analyses and wet lab experiments that suggest several parallel layers of functional diversification during evolution of the three Bep repertoires from a single ancestral effector. Our analyses show that the Beps of B. ancashensis share many features with the two other repertoires, but may represent a more ancestral state that has not yet unleashed the adaptive potential of such an effector set. We anticipate that the effectors of B. ancashensis will enable future studies to dissect the evolutionary history of Bartonella effectors and help unraveling the evolutionary forces underlying bacterial host adaptation

Bartonella species and their ectoparasites: Selective host adaptation or strain selection between the vector and the mammalian host?

A wide range of blood-sucking arthropods have either been confirmed or are suspected as important vectors in Bartonella transmission to mammals, including humans. Overall, it appears that the diversity of Bartonella species DNA identified in ectoparasites is much broader than the species detected in their mammalian hosts, suggesting a mechanism of adaptation of Bartonella species to their host-vector ecosystem. However, these mechanisms leading to the fitness between the vectors and their hosts still need to be investigated. (C) 2011 Elsevier Ltd. All rights reserved

Identification of novel Bartonella spp. in bats and evidence of Asian gray shrew as a new potential reservoir of Bartonella

Many studies indicated that small mammals are important reservoirs for Bartonella species. Using molecular methods, several studies have documented that bats could harbor Bartonella. This study was conducted to investigate the relationship of Bartonella spp. identified in bats and small mammals living in the same ecological environment. During May 2009 and March 2010, a total of 102 blood specimens were collected. By whole blood culture and molecular identification, a total of 6 bats, 1 rodent and 9 shrews were shown to be infected by Bartonella species. After sequencing and phylogenetic analyses of the sequences of gltA, ftsZ, rpoB and ribC genes, these specific isolates from bats were not similar to the known Bartonella species (the similarity values were less than 91.2%, 90.5%, 88.8%, and 82.2%, respectively); these isolates formed an independent clade away from other known Bartonella type strains. The Bartonella spp. isolated from small mammals, which were closely related to Bartonella tribocorum, Bartonella elizabethae, Bartonella grahamii, Bartonella rattimassiliensis and Bartonella queenslandensis, were similar to the findings in previous studies worldwide. Therefore, the results implied that the species of Bartonella strains isolated from small mammals were different from those identified in bats. Our results strongly suggested that the bat isolate could be a new Bartonella species. This study is also the first one to isolate Bartonella organisms from Asian gray shrews, Crocidura attenuata tanakae. (C) 2011 Elsevier B.V. All rights reserved

Bartonella and Babesia infections in cattle and their ticks in Taiwan

Bartonella and Babesia infections and the association with cattle breed and age as well as tick species infesting selected cattle herds in Taiwan were investigated. Blood samples were collected from 518 dairy cows and 59 beef cattle on 14 farms and 415 ticks were collected from these animals or in a field. Bartonella and Babesia species were isolated and/or detected in the cattle blood samples and from a selected subset (n = 254) of the ticks either by culture or DNA extraction, PCR testing and DNA sequence analysis. Bartonella bovis was isolated from a dairy cow and was detected in 25(42.4%) beef cattle and 40(15.7%) tick DNA samples. This is the first isolation of B. bovis from cattle in Asia and detection of a wide variety of Bartonella species in Rhipicephalus microplus. Babesia spp. were detected only on one farm from dairy cows either infected by Babesia bovis (n = 10, 1.9%) or B. bigemina (n = 3, 0.6%). (C) 2010 Elsevier Ltd. All rights reserved

Bacterial zoonoses transmitted by Household pets: State of the Art and Future perspectives for targeted research and policy actions

The close contact between household pets and people offers favourable conditions for bacterial transmission. In this article, the aetiology, prevalence, transmission, impact on human health and preventative measures are summarized for selected bacterial zoonoses transmissible by household pets. Six zoonoses representing distinct transmission routes were selected arbitrarily based on the available information on incidence and severity of pet-associated disease caused by zoonotic bacteria: bite infections and cat scratch disease (physical injuries), psittacosis (inhalation), leptospirosis (contact with urine), and campylobacteriosis and salmonellosis (faecal–oral ingestion). Antimicrobial resistance was also included due to the recent emergence of multidrug-resistant bacteria of zoonotic potential in dogs and cats. There is a general lack of data on pathogen prevalence in the relevant pet population and on the incidence of human infections attributable to pets. In order to address these gaps in knowledge, and to minimize the risk of human infection, actions at several levels are recommended, including: (1) coordinated surveillance of zoonotic pathogens and antimicrobial resistance in household pets, (2) studies to estimate the burden of human disease attributable to pets and to identify risk behaviours facilitating transmission, and (3) education of those in charge of pets, animal caretakers, veterinarians and human medical healthcare practitioners on the potential zoonotic risks associated with exposure to pets. Disease-specific recommendations include incentives to undertake research aimed at the development of new diagnostic tests, veterinary-specific antimicrobial products and vaccines, as well as initiatives to promote best practices in veterinary diagnostic laboratories and prudent antimicrobial usage

Epidemiology of Bartonella Infection in Rodents and Shrews in Taiwan

P>During the period of August 2002 and November 2004, an epidemiological investigation for Bartonella infection was conducted in small mammals in Taiwan. Using whole blood culture on chocolate agar plates, Bartonella species were successfully isolated from 41.3% of the 310 animals tested. The isolation rate of Bartonella species varied among different animal species, including 52.7% of the 169 Rattus norvegicus, 28.6% of the 126 Sucus murinus, 10% of the 10 Rattus rattus and 66.7% of the three Rattus losea. Bacteremia prevalence also varied with the origin of the animals, as 56.2% of the animals captured on farms, 38.6% of the ones captured at harbour sites and 11.8% of the animals captured from urban areas were bacteremic. Through molecular analysis of the gltA gene and 16S/23S intergenic spacer region, genetic diversity of Bartonella organisms was identified, including strains closely related to Bartonella tribocorum, Bartonella grahamii, Bartonella elizabethae, Bartonella phoceensis and Bartonella rattimassiliensis. Moreover, this is the first report of zoonotic B. elizabethae and B. grahamii identified in R. losea, the lesser rice-field rat. Various Bartonella species were identified in R. norvegicus, compared to 97.2% of Suncus murinus with unique Bartonella species. By indirect immunofluorescence antibody test, using various rodent Bartonella species as antigens, consistently low percentage of seropositivity implied that small mammals may play a role as competent reservoirs of Bartonella species in Taiwan. Future studies need to be conducted to determine whether these Bartonella species would be responsible for human cases of unknown fever or febrile illness in Taiwan, especially zoonotic B. elizabethae and B. grahamii

Bartonella Infection in Shelter Cats and Dogs and Their Ectoparasites

Mainly through vector transmission, domestic cats and dogs are infected by several Bartonella spp. and represent a large reservoir for human infections. This study investigated the relationship of prevalences of Bartonella infection in shelter dogs and cats and various ectoparasite species infesting them (fleas, ticks, and lice). Moreover, relationships between Bartonella infection and animal gender and age and presence of ectoparasites were analyzed. Blood samples were collected from 120 dogs and 103 cats. There were 386 ticks and 36 fleas harvested on these dogs, and 141 fleas, 4 ticks, and 2 lice harvested on these cats. Isolation/detection of Bartonella sp. was performed by culture, polymerase chain reaction (PCR), and partial sequencing. Bartonella was isolated from 21 (20.4%) cats and detected by PCR from 20 (19.4%) cats, 2 (1.7%) dogs, 55 (39%) fleas collected from cats, 28 (10%) ticks DNA samples, and 1 (2.8%) flea collected from dogs. When combining culture and PCR data, 27 cats and 55 fleas collected on cats were positive for Bartonella henselae or Bartonella clarridgeiae, but none were coinfected. Approximately half of the B. henselae isolates from 21 cats were B. henselae type I. Moreover, B. henselae, Bartonella phoceensis, Bartonella queenslandensis, Bartonella rattimassiliensis, Bartonella elizabethae DNA was detected in ticks collected from dogs and one flea was B. clarridgeiae PCR positive. This is the first report of such a wide variety of Bartonella spp. detected in Rhipicephalus sanguineus. Further studies are required to understand the relative importance of these ectoparasites to transmit Bartonella spp. in dogs and cats