Molecular Detection of Tick-Borne Pathogens Associated With Ixodid Tick Species Infesting Migratory Songbirds and Ruminants

Ticks are hematophagous arthropods and capable of inoculating various infectious agents to their vertebrate hosts. Ticks attached to birds and ruminants are capable of carrying tick-transmitted microorganisms. In our study, the prevalence of tick-borne pathogens was examined in ticks infesting migratory songbirds and Pakistani ruminants. During spring migration seasons, ticks were removed from northward-migrating songbirds in Louisiana and identified as Amblyomma Jongirostre, Amblyomma nodosum, Amb/yomma ca/caratum, Amblyomma maculatum, and Haemaphysalis species, all are considered as Neotropical ticks. Ticks removed from ruminants were identified as Hya/omma anatolicum, Hyalomma dromedarii, Rhipicephalus microplus, and Rhipicephalus sanguineus. A total of 112 and 72 bacterial genera identified in ticks and migratory songbirds respectively by using 454-based pyrosequencing. Taxonomic classification of ticks from ruminants reveals that the most predominant phylum was proteobacter in both Hyalomma spp. and firmicutes in Rhipicephalus microplus. The overall microbial diversity found highest in Rhipicephalus microplus (one-host tick), Hyalomma dromedarii (two-host tick), and Hyalomma anatolicum (three-host ticks). The prevalence of SFGR were determined by amplifying ompA (outer membrane protein A) gene. The nucleotide sequence of amplicons were homologous with several SFGR including Rickettsia amblyommii, was confirmed by ompB probe based qPCR assay. Rickettsia amblyommii was found predominant in Amb/yomma longirostre and Haemaphysalis species among the Neotropical tick species as well as most prevalent in ticks with the lowest microbial diversity and least prevalent in highest microbial diversity in the ticks from ruminants. Our results indicate a rich tick and microbial diversity of epidemiological roles infesting the migratory songbirds and ruminants in Pakistan

SOURCE ATTRIBUTION, ANTIBIOTIC RESISTANCE AND VIRULENCE PROPERTIES OF SALMONELLA SEROTYPES ISOLATED FROM CLINICALLY DIAGNOSED HUMAN SALMONELLOSIS CASES FROM TENNESSEE

Non-typhoidal Salmonella (NTS) infection is one of the major causes of diarrheal disease throughout the world. Recently, an increase in trend of human S. Newport, S. Javiana, and S. Mississippi infection has been observed in Tennessee. The exact reason for the increase of the NTS infection by these three serotypes is not known. The sources of human S. Javiana infections are not well characterized. This study performed a systematic literature review to identify potential sources of human S. Javiana infection based on available scientific evidence. This study identified the food (such as tomatoes, watermelons, paprika-spice, and cheese), drinking well water, and non-foodborne (such as animal contact) exposures are responsible for the transmission of human S. Javiana infection.The current study explored the potential risk factors associated with any of the above mentioned three Salmonella serotypes among data from FoodNet and TDH consisting of 2,757 culture-confirmed salmonellosis cases from Tennessee during 2013 through 2015. A case-case analysis was performed to identify potential risk factors for human NTS infections caused by any of the three selected serotypes. This study identified the following risk factors that were independently associated with the cases: recreational water [OR adjusted= 1.7 (95% CI 0.9, 3.0)], dog [OR adjusted= 1.6 (95% CI 0.9, 2.7)], pet treats [OR adjusted= 3.0 (95% CI 1.6, 5.5)], visit to a farm [ORadjusted = 2.3 (95% CI 0.9, 6.0)], ice cream [OR adjusted= 1.5 (95% CI 0.9, 2.4], and frozen pizza [OR adjusted= 1.5 (95% CI 0.9, 2.5)]. This study also demonstrated that the Salmonella serotypes assessed in this study harbors antibiotic resistance characteristics as well as several virulence genes. Additionally, the current study identified the association between antibiotic resistance and virulence genes of Salmonella isolates. The virulent gene, ssaQ, was observed to be significantly associated with antibiotic-resistant Salmonella [2 (df=1) = 12.16, P idk adjusted = 0.019]. Further investigation with larger sample is needed to better understand this association. To conclude, this study points out the need for routine surveillance of human NTS infections, as well as increased public awareness and practice of hand hygiene to prevent the occurrence of the infection

Transformation of Agricultural Land for Urbanisation, Infrastructural Development and Question of Future Food Security: Cases from Parts of Hugli District, West Bengal

Developing countries of the world encounter urbanisation and infrastructural development in or around the fertile tracts and the absence of any landuse plan for desired land use change has led to conversion of farmlands, which is detrimental to future food security and environmental quality. Hugli district is traditionally well known as one of the most prosperous agricultural regions of West Bengal but the district is experiencing rapid urban extension and infrastructural development towards productive agricultural land since 1991. This has caused decline in the amount of agricultural production which may be treated as an indicator of increasing threat to the long run sustainable livelihood security of the people of the whole of West Bengal. This article critically explores the transformation of agricultural (farm) land because of growing rate of urbanisation and infrastructural development, which in turn poses the question of threat to food (in) security. Although, this is a growing problem across the universe, this article probes the future food security questions of Hugli district, West Bengal by examining the impact of the highly intertwined indicators of urbanisation and infrastructural development on agricultural (farm) land use and its effect on food security. Regression analysis, Spearman’s Ranking Correlation Coefficient, Remote Sensing technologies, Markov Chain Model, Projection of future population growth and yield rate are employed to understand the depth of the problem. The result not only shows a direct negative correlation between urban extension and agricultural areal contraction but also the supervised classification of satellite imageries shows that there is rapid change of rural land use from 1996-2016. There is no match between future population growth and future yield rate of crops and the Markov Chain Model further predicts that the cropland will decrease from 62.77% to 42.90% and the built up area will increase from 31.86% to 54.63% of the total area from 2016 to 2056. &nbsp

The Microbiome of Neotropical Ticks Parasitizing On Passerine Migratory Birds

Seasonal migration of passerine birds between temperate North America and tropical Central and South America is an ecological phenomenon. Migration of birds has been associated with the introduction of ectoparasites like ticks or tick-borne pathogens across the avian migration routes. In this study, the microbial diversity was determined in the ticks and bird DNA samples using 454 pyrosequencing of bacterial 16S rRNA gene. Tick DNA samples showed the dominance of genera Lactococcus, Francisella, Raoultella, Wolbachiaand Rickettsia across all the ticks, but birds DNA did not share common microbial diversity with ticks. Furthermore, “Candidatus Rickettsia amblyommii” infection in the 91 ticks collected off the songbirds was also quantified by qPCR assay. Interestingly, “Candidatus R. amblyommii” was tested positive in 24 ticks (26% infection), and infection varied from as low as three copies to thousands of copies, but bird blood samples showed no amplification. Our results provide evidence that songbirds serve as transport carrier for immature ticks, and less likely to be a reservoir for “Candidatus R. amblyommii”

A Snapshot of the Microbiome of \u3ci\u3eAmbylomma tuberculatum\u3c/i\u3e Ticks Infesting the Gopher Tortoise, an Endangered Species

The gopher tortoise tick, Amblyomma tuberculatum, has a unique relationship with the gopher tortoise, Gopherus polyphemus, found in sandy habitats across the southeastern United States. We aimed to understand the overall bacterial community associated with A. tuberculatum while also focusing on spotted fever group Rickettsia. These tortoises in the Southern Mississippi region are a federally threatened species; therefore, we have carefully trapped the tortoises and removed the species-specific ticks attached to them. Genomic DNA was extracted from individual ticks and used to explore overall bacterial load using pyrosequencing of bacterial 16S rRNA on 454-sequencing platform. The spotted fever group of Rickettsia was explored by amplifying rickettsial outer membrane protein A (rompA) gene by nested PCR. Sequencing results revealed 330 bacterial operational taxonomic units (OTUs) after all the necessary curation of sequences. Four whole A. tuberculatum ticks showed Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes as the most dominant phyla with a total of 74 different bacterial genera detected. Together Rickettsiae and Francisella showed \u3e85% abundance, thus dominating the bacterial community structure. Partial sequences obtained from ompA amplicons revealed the presence of an uncharacterized Rickettsia similar to the Rickettsial endosymbiont of A. tuberculatum. This is the first preliminary profile of a complete bacterial community from gopher tortoise ticks and warrants further investigation regarding the functional role of Rickettsial and Francisella-like endosymbionts in tick physiology

Airborne Bacterial Exposure at Workers\u27 Breathing Height in an Organic Farm of Rural Georgia

Organic farming has potentials to contribute substantially to future sustainable agricultural production by improving soil quality, pest control, and reduction of adverse environmental impacts in rural agricultural communities. On the other hand, application of natural farmyard manure may increase the microbial biomass in this environment and consequently microbial exposure levels among workers could be increased. To explore this possibility of excess exposure, particularly to airborne bacteria, we conducted air sampling at the vicinity of poultry and dairy sections of a large organic farm in a rural Georgia location. For air sampling, a Biostage viable cascade impactor was utilized, which comprises an inlet cone, precision-drilled 400-hole impactor stage, and a base that holds a standard-size agar plate (Tryptic soy agar). A high flow QuickTake 30 pump connected to this impactor pulls microorganisms in air at 28.3 L/min flow rate through the holes (jets) where they are collected on the agar surface for approx. ten minutes. After sampling, agar plates containing the samples were placed in an ice chest with blue ice and plates were incubated at 30å±2å¡C for 24 to 72 h. Colonies were counted and converted to airborne concentrations (CFU/m3) followed by positive hole corrections. For understanding overall microbial activity in the nearby soil surfaces, ATP levels were determined (using a kit and a luminometer) in swabbed dust samples collected from 10 cm2 soil surfaces. Average airborne concentrations of culturable bacteria near the poultry and dairy sections (n = 9) ranged from 125 to 297 CFU/m3 and 91 to 165 CFU/m3, respectively for airborne bacteria and means (average values) of 112 - 1359 RLU/sample (872.7 Std. Dev.) and 701 Ò 816 RLU/sample (515.1 Std. Dev.), respectively for ATP levels. Preliminary data showed that bacterial exposure levels in selected locations are generally lower than previous measurements in other farming environments conducted by other researchers

Importation of Exotic Ticks and Tick-Borne Spotted Fever Group Rickettsiae into the United States by Migrating Songbirds

Birds are capable of carrying ticks and, consequently, tick-transmitted microorganisms over long distances and across geographical barriers such as oceans and deserts. Ticks are hosts for several species of spotted fever group rickettsiae (SFGR), which can be transmitted to vertebrates during blood meals. In this study, the prevalence of this group of rickettsiae was examined in ticks infesting migratory songbirds by using polymerase chain reaction (PCR). During the 2009 and 2010 spring migration season, 2064 northward-migrating passerine songbirds were examined for ticks at Johnson Bayou, Louisiana. A total of 91 ticks was removed from 35 individual songbirds for tick species identification and spotted fever group rickettsia detection. Ticks were identified as Haemaphysalis juxtakochi (n = 38, 42%), Amblyomma longirostre (n = 22, 24%), Amblyomma nodosum (n = 17, 19%), Amblyomma calcaratum (n = 11, 12%), Amblyomma maculatum (n = 2, 2%), and Haemaphysalis leporispalustris (n = 1, 1%) by comparing their 12S rDNAgene sequence to homologous sequences in GenBank. Most of the identified ticks were exotic species originating outside of the United States. The phylogenetic analysis of the 71 ompA gene sequences of the rickettsial strains detected in the ticks revealed the occurrence of 6 distinct rickettsial genotypes. Two genotypes (corresponding to a total of 28 samples) were included in the Candidatus Rickettsia amblyommii clade (less than 1% divergence), 2 of them (corresponding to a total of 14 samples) clustered with Rickettsia sp. “Argentina” with less than 0.2% sequence divergence, and 2 of them (corresponding to a total of 27 samples), although closely related to the R. parkeri–R. africae lineage (2.50–3.41% divergence), exhibited sufficient genetic divergence from its members to possibly constitute a new rickettsial genotype. Overall, there does not seem to be a specific relationship between exotic tick species, the rickettsiae they harbor, or the reservoir competence of the corresponding bird species