Diversity of the Anisoptera & Zygoptera (Odonata: Insecta) of Swat, Pakistan

Odonates are important biological control agents for the control of insect pests and insect disease vectors of medical and veterinary importance. The present study was conducted to evaluate the odonate fauna of Swat, Pakistan from March to October 2019. A total of 200 specimens of odonates were collected from diverse habitats. The collected specimens of the order Odonata belonged to 5 families, three families of suborder Anisoptera namely Libellulidae, Gomphidae and Aeshnidae while two families of suborder Zygoptera (Chlorocyphidae and Coenagrionidae). The specimens were categorized into 12 genera and 22 species. Libellulidae was the dominant family (n = 138) accounting for 69% of the odonate fauna. Orthetrum was the dominant genus (n = 73) of suborder Anisoptera accounting for 36.5% of the odonate fauna. The least dominant genera were Anax, Paragomphus and Rhyothemis (n = 5 each) accounting each for 2.5% of the odonate fauna. In Zygoptera, the dominant genus was Ceriagrion (12.5%) and the least dominant genus was Ischnura (6%). Pantala flavescens (Fabricius, 1798) was the most abundant odonate species in the study area recorded from all surveyed habitats. Shannon Diversity Index (H) was 2.988 and Simpson Diversity Index (D) was 0.95 for the collected odonate fauna. The highest abundance of Odonata was recorded in August, September and May while no odonate species were recorded in January, February, November and December. Lotic water bodies were the most suitable habitats with abundant odonate fauna. Anax immaculifrons (Rambur, 1842) was the largest sized odonate species having a wingspan of 53.2±1.63 mm and body length of 56.3 ± 0.4 mm. The present study shows the status of odonate fauna of Swat, Pakistan in diverse habitats and seasonsonal variation throughout the year. Further work is recommended to bridge the gaps in the existing literature.

Teaching of Veterinary Parasitology to University students in Trinidad, West Indies; are our local wildlife species neglected?

Parasites of veterinary importance have been heavily focused on domesticated livestock that was introduced into the neo-tropics. The text used in the teaching parasitology to veterinary students in Trinidad has only investigated the parasites of domesticated species. In the reviewed veterinary parasitology text no mention was made on the parasites that affect wild neo-tropical animals. Information on wild neo-tropical animals had to be sourced from texts on the management of wild life animals in the Neotropics. The texts that were reviewed in this document spanned from the mid-1950s to 2020. The information presented in this review reveals the exhaustive work done on the parasites of domesticated species but also revealed little information on neo-tropical animals with the potential for domestication. In conclusion, this review reveals the gap of information that is missing from parasitology texts used in the teaching of veterinary students. In the future these parasitology texts can be revised to include chapters on the parasites of neo-tropical animals with the potential for domestication. At present students that graduate from the veterinary parasitology course has little information on the parasites of animals which are present in their ‘backyards’.

The vacuolar iron transporter mediates iron detoxification in Toxoplasma gondii

Iron is essential to living cells, acting as a cofactor in a number of important enzymes in metabolism; however in the absence of correct storage iron forms dangerous oxygen radicals. In both yeast and plants, iron is stored in a membrane-bound vacuole through the action of a vacuolar iron transporter (VIT). This transporter is conserved in the apicomplexan family of obligate intracellular parasites, including in Toxoplasma gondii, a pathogen of medical and veterinary importance. Here, we assess the role of VIT, and iron storage, in T. gondii. We show that iron is restricted to a compartment in the parasite that does not overlap with zinc. By deleting VIT we find a slight growth defect in vitro, however the absence of VIT leads to hypersensitivity to iron, confirming its essential role in iron detoxification in the parasite. This hypersensitivity can be rescued by scavenging of oxygen radicals. In the absence of VIT, parasites store less iron and are at a growth disadvantage when moving into an iron-depleted environment. We show parasite VIT expression is regulated by iron levels at both the transcript and protein level, and by altering the distribution of VIT within the cell. In the absence of VIT, we find that T. gondii responds by altering expression of genes with a role in iron metabolism and by increasing the activity of the antioxidant protein catalase. We also show that iron detoxification has an important role both in parasite survival within macrophages and in virulence in a mouse model. Together, by demonstrating a critical role for VIT during iron detoxification in T. gondii, we reveal the importance of iron storage in the parasite and provide the first insight into the machinery involved.

First list of parasitoids in flies of medical, veterinary, and forensic importance in Rio Grande do Sul – Brazil

Necrophagous flies are of great importance for human and animal health. In places where their development occurs, parasitoids can be used as a tool to control these dipterans. In Brazil, the fauna of these parasitoids has been investigated in some regions. However, in Rio Grande do Sul, it is known the occurrence of only one species. Thus, this study aimed to create the first list of parasitoids in flies of medical and veterinary importance in Southern Brazil. Collections took place in the municipality of Pelotas (31º 42’ S; 52º 18’ W). Three replicates consisting of a 500 g bovine liver chunk placed in a tray were exposed to open air for 20 days. Then pupae were individualized and observed until their emergence. We identified 4,882 adult flies of Calliphoridae, Fanniidae, Muscidae, and Sarcophagidae. 4,040 parasitoids emerged, belonging to eight species, of which Nasonia vitripennis, Spalangia cameroni, Spalangia chontalensis, and Tachinephagus zealandicus are new records in Rio Grande do Sul state. Also, three undescribed species of the genus Aphaereta were collected. In spite of being the first attempt to inventory the fauna of hymenopteran parasitoids, this study may help in the development of management programs of these dipterans in the region.

Discovery of New Microneme Proteins in Cryptosporidium parvum and Implication of the Roles of a Rhomboid Membrane Protein (CpROM1) in Host–Parasite Interaction

Apicomplexan parasites possess several unique secretory organelles, including rhoptries, micronemes, and dense granules, which play critical roles in the invasion of host cells. The molecular content of these organelles and their biological roles have been well-studied in Toxoplasma and Plasmodium, but are underappreciated in Cryptosporidium, which contains many parasites of medical and veterinary importance. Only four proteins have previously been identified or proposed to be located in micronemes, one of which, GP900, was confirmed using immunogold electron microscopy (IEM) to be present in the micronemes of intracellular merozoites. Here, we report on the discovery of four new microneme proteins (MICs) in the sporozoites of the zoonotic species C. parvum, identified using immunofluorescence assay (IFA). These proteins are encoded by cgd3_980, cgd1_3550, cgd1_3680, and cgd2_1590. The presence of the protein encoded by cgd3_980 in sporozoite micronemes was further confirmed using IEM. Cgd3_980 encodes one of the three C. parvum rhomboid peptidases (ROMs) and is, thus, designated CpROM1. IEM also confirmed the presence of CpROM1 in the micronemes of intracellular merozoites, parasitophorous vacuole membranes (PVM), and feeder organelles (FO). CpROM1 was enriched in the pellicles and concentrated at the host cell–parasite interface during the invasion of sporozoites and its subsequent transformation into trophozoites. CpROM1 transcript levels were also higher in oocysts and excysted sporozoites than in the intracellular parasite stages. These observations indicate that CpROM1, an intramembrane peptidase with membrane proteolytic activity, is involved in host–parasite interactions, including invasion and proteostasis of PVM and FO.

Rationally designed mariner vectors for functional genomic analysis of Actinobacillus pleuropneumoniae and other Pasteurellaceae species by transposon-directed insertion-site sequencing (TraDIS)

Comprehensive identification of conditionally essential genes requires efficient tools for generating high-density transposon libraries that, ideally, can be analysed using next-generation sequencing methods such as Transposon Directed Insertion-site Sequencing (TraDIS). The Himar1 (mariner) transposon is ideal for generating near-saturating mutant libraries, especially in AT-rich chromosomes, as the requirement for integration is a TA dinucleotide, and this transposon has been used for mutagenesis of a wide variety of bacteria. However, plasmids for mariner delivery do not necessarily work well in all bacteria. In particular, there are limited tools for functional genomic analysis of Pasteurellaceae species of major veterinary importance, such as swine and cattle pathogens, Actinobacillus pleuropneumoniae and Pasteurella multocida, respectively. Here, we developed plasmids, pTsodCPC9 and pTlacPC9 (differing only in the promoter driving expression of the transposase gene), that allow delivery of mariner into both these pathogens, but which should also be applicable to a wider range of bacteria. Using the pTlacPC9 vector, we have generated, for the first time, saturating mariner mutant libraries in both A. pleuropneumoniae and P. multocida that showed a near random distribution of insertions around the respective chromosomes as detected by TraDIS. A preliminary screen of 5000 mutants each identified 8 and 14 genes, respectively, that are required for growth under anaerobic conditions. Future high-throughput screening of the generated libraries will facilitate identification of mutants required for growth under different conditions, including in vivo, highlighting key virulence factors and pathways that can be exploited for development of novel therapeutics and vaccines.

Molecular characterization of Fasciola isolates collected from sheep, goats and cattle in Kisumu, Baringo and Narok Counties, Kenya

Fasciolosis is a neglected trematode infection of public health and veterinary importance caused by Fasciola gigantica and Fasciola hepatica. Molecular analysis using the internal transcribed spacers’ ITS-1 and ITS-2 of nuclear ribosomal DNA is useful in distinguishing Fasciola species. This study aimed to characterize liver flukes from sheep, goats and cattle using these genetic markers. Fifty nine adult Fasciola specimens were collected from livers of naturally infected sheep, goats and cattle at selected abattoirs in Kisumu, Baringo and Narok Counties. Sequence comparison of ITS-1 and ITS-2 sequences of Fasciola isolates from this study and sequences in Genbank was carried out. A maximum likelihood tree was constructed for phylogenetic analysis. Analysis of ITS-1 and ITS-2 rDNA sequences revealed that F. hepatica and F. gigantica caused infection in both cattle and sheep and in goats only F. gigantica caused infection. The sequenced PCR amplicons showed a close relationship between Fasciola species in this study with Fasciola isolates from other regions in the world. Phylogenetic analysis showed that sequences of F. hepatica are similar to the sequence from Spain, China and Tunisia obtained from GenBank. The sequences of F. gigantica in this study have similarity to the sequence from Iran and Burkina Faso. Data from this study provides information that serves as basis for further studies on the distribution of F. gigantica and F. hepatica in other localities in Kenya, and is also important in designing epidemiological and control programmes for zoonotic fascioliasis.

Molecular Detection of Tick-Borne Pathogens in American Bison (Bison bison) at El Uno Ecological Reserve, Janos, Chihuahua, Mexico

American bison (Bison bison) is listed as near-threatened and in danger of extinction in Mexico. Recent studies have demonstrated the presence of several emerging pathogens at the Janos Biosphere Reserve (JBR), inhabited by one wild herd of American bison. Blood samples were collected from 26 American bison in the JBR. We tested for the presence of Anaplasma marginale, Babesia bigemina, B. bovis, Borrelia burgdorferi sensu lato, and Rickettsia rickettsii DNA using nested and semi-nested PCR protocols performing duplicates in two different laboratories. Results showed three animals (11.5%) positive for B. burgdorferi s. l., three more (11.5%) for Rickettsia rickettsii, and four (19.2%) for B. bovis. Two individuals were co-infected with B. burgdorferi s. l. and B. bovis. We found no animals positive for A. marginale and B. bigemina. This is the first report in America of R. rickettsii in American bison. American bison has been described as an important reservoir for pathogens of zoonotic and veterinary importance; thus, the presence of tick-borne pathogen DNA in the JBR American bison indicates the importance of continuous wildlife health surveys.