Rapid detection and differentiation of Theileria annulata, T. orientalis and T. sinensis using high-resolution melting analysis

Molecular Epidemiology of Ticks and Tick-Borne Pathogens in the Ta-Pa Mountain Area of Chongqing, China

To validate the prevalence and biodiversity of ticks and tick-borne pathogens in Chongqing, a total of 601 ticks were collected from dogs, cattle, and goats within the Ta-pa Mountain range in Chongqing, China. Five distinct tick species were identified, including Ixodes ovatus (1.66%, 10/601), I. acutitarsus (0.50%, 3/601), Haemaphysalis flava (10.32%, 62/601), Ha. hystricis (9.82%, 59/601), and Ha. longicornis (77.70%, 467/601). A suit of semi-nest PCR and nest PCR primers were custom-synthesized for the detection of tick-borne pathogens. The analysis yielded positive results for 7.15% Rickettsia (Candidatus R. principis, R. japonica, and R. raoultii), 3.49% Anaplasma (A. bovis and A. capra), 1.16% Ehrlichia, 1.83% Coxiella burnetii, and 3.49% protozoa (Theileria. capreoli, T. orientalis, T. luwenshuni, and Babesia sp.) in ticks. Notably, Ca. R. principis was identified for the first time in I. ovatus and Ha. longicornis. These findings underscore the significant prevalence and diversity of ticks and their associated pathogens within the Chongqing Ta-pa Mountain region. This study accordingly provides an extensive dataset that contributes to the epidemiological understanding and disease prevention strategies for tick-borne illnesses in the local area.

Fast Track Diagnostic Tools for Clinical Management of Sepsis: Paradigm Shift from Conventional to Advanced Methods

Sepsis is one of the deadliest disorders in the new century due to specific limitations in early and differential diagnosis. Moreover, antimicrobial resistance (AMR) is becoming the dominant threat to human health globally. The only way to encounter the spread and emergence of AMR is through the active detection and identification of the pathogen along with the quantification of resistance. For better management of such disease, there is an essential requirement to approach many suitable diagnostic techniques for the proper administration of antibiotics and elimination of these infectious diseases. The current method employed for the diagnosis of sepsis relies on the conventional culture of blood suspected infection. However, this method is more time consuming and generates results that are false negative in the case of antibiotic pretreated samples as well as slow-growing microbes. In comparison to the conventional method, modern methods are capable of analyzing blood samples, obtaining accurate results from the suspicious patient of sepsis, and giving all the necessary information to identify the pathogens as well as AMR in a short period. The present review is intended to highlight the culture shift from conventional to modern and advanced technologies including their limitations for the proper and prompt diagnosing of bloodstream infections and AMR detection.

Metabolomic profiling of bovine leucocytes transformed by Theileria annulata under BW720c treatment

Background

When Theileria annulata infects host cells, it undertakes unlimited proliferation as tumor cells. Although the transformed cells will recover their limited reproductive characteristics and enter the apoptosis process after treatment with buparvaquone (BW720c), the metabolites and metabolic pathways involved are not clear.

Methods

The transformed cells of T. annulata were used as experimental materials, and the buparvaquone treatment group and DMSO control group were used. Qualitative and quantitative analysis was undertaken of 36 cell samples based on the LC–QTOF platform in positive and negative ion modes. The metabolites of the cell samples after 72 h of drug treatment were analyzed, as were the different metabolites and metabolic pathways involved in the BW720c treatment. Finally, the differential metabolites and metabolic pathways in the transformed cells were found.

Results

A total of 1425 metabolites were detected in the negative ion mode and 1298 metabolites were detected in the positive ion mode. After drug treatment for 24 h, 48 h, and 72 h, there were 56, 162, and 243 differential metabolites in negative ion mode, and 35, 121, and 177 differential metabolites in positive ion mode, respectively. These differential metabolites are mainly concentrated on various essential amino acids.

Conclusion

BW720c treatment induces metabolic disturbances in T. annulata-infected cells by regulating the metabolism of leucine, arginine, and l-carnitine, and induces host cell apoptosis.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-022-05450-0.

A high-resolution melting assay to differentiate a peste des petits ruminants virus vaccine strain from field isolates in Turkey

Peste des petits ruminants (PPR) mostly affects small ruminants. Vaccination with attenuated vaccines derived from PPR virus (PPRV) provides successful protection against the disease. However, current molecular methods are unable to distinguish vaccine strains from field strains. In this study, we used an EvaGreen-based high-resolution melting (HRM) assay to differentiate a PPRV vaccine strain (Nigeria 75/1) from Turkish field isolates of lineage IV based on melting peaks and melting profiles.

High-resolution melting analysis identifies reservoir hosts of zoonotic Leishmania parasites in Tunisia

BACKGROUND

Leishmaniasis is endemic in Tunisia and presents with different clinical forms, caused by the species Leishmania infantum, Leishmania major, and Leishmania tropica. The life cycle of Leishmania is complex and involves several phlebotomine sand fly vectors and mammalian reservoir hosts. The aim of this work is the development and evaluation of a high-resolution melting PCR (PCR-HRM) tool to detect and identify Leishmania parasites in wild and domestic hosts, constituting confirmed (dogs and Meriones rodents) or potential (hedgehogs) reservoirs in Tunisia.

METHODS

Using in vitro-cultured Leishmania isolates, PCR-HRM reactions were developed targeting the 7SL RNA and HSP70 genes. Animals were captured or sampled in El Kef Governorate, North West Tunisia. DNA was extracted from the liver, spleen, kidney, and heart from hedgehogs (Atelerix algirus) (n = 3) and rodents (Meriones shawi) (n = 7) and from whole blood of dogs (n = 12) that did not present any symptoms of canine leishmaniasis. In total, 52 DNA samples were processed by PCR-HRM using both pairs of primers.

RESULTS

The results showed melting curves enabling discrimination of the three Leishmania species present in Tunisia, and were further confirmed by Sanger sequencing. Application of PCR-HRM assays on reservoir host samples showed that overall among the examined samples, 45 were positive, while seven were negative, with no Leishmania infection. Meriones shawi were found infected with L. major, while dogs were infected with L. infantum. However, co-infections with L. major/L. infantum species were detected in four Meriones specimens and in all tested hedgehogs. In addition, multiple infections with the three Leishmania species were found in one hedgehog specimen. Sequence analyses of PCR-HRM products corroborated the Leishmania species found in analyzed samples.

CONCLUSIONS

The results of PCR-HRM assays applied to field specimens further support the possibility of hedgehogs as reservoir hosts of Leishmania. In addition, we showed their usefulness in the diagnosis of canine leishmaniasis, specifically in asymptomatic dogs, which will ensure a better evaluation of infection extent, thus improving elaboration of control programs. This PCR-HRM method is a robust and reliable tool for molecular detection and identification of Leishmania and can be easily implemented in epidemiological surveys in endemic regions.

Mammalian species identification using ISSR-HRM technique

Wildlife trading and the illegal hunting of wildlife are contributing factors to the biodiversity crisis that is presently unfolding across the world. The inability to control the trade of animal body parts or available biological materials is a major challenge for those who investigate wildlife crime. The effective management of this illegal trade is an important facet of wildlife forensic sciences and can be a key factor in the enforcement of effective legislation surrounding the illegal trade of protected and endangered species. However, the science of wildlife forensics is limited by the absence of a comprehensive database for wildlife investigations. Inter-simple sequence repeat markers (ISSR) coupled with high resolution melting analysis (HRM) have been effectively used for species identification of 38 mammalian species. Six primers of the ISSR markers were chosen for species identification analysis. From six ISSR primers resulting in a range of accuracy of 33.3%-100% and 100% in terms of precision in every primer. Furthermore, 161 mammalian samples were 100% distinguished to the correct species using these six ISSR primers. ISSR-HRM analysis was successfully employed in determining mammal identification among varying mammalian species, and thus could serve as an effective alternative tool or technique in the species identification process. This option would offer researchers a heightened level of convenience in terms of its performance and the ease with which researchers or field practice veterinarians would be able to interpret results in effectively identifying animal parts at wildlife investigation crime scenes.