Since porcine reproductive and respiratory syndrome virus (PRRSV) was first described in China in 1996, several genetically distinct strains of PRRSV have emerged with varying pathogenicity and severity, thereby making the prevention and control of PRRS more difficult in China and worldwide. Between 2017 and 2021, the detection rate of NADC34-like strain in China increased. To date, NADC34-like strains have spread to 10 Chinese provinces and have thus developed different degrees of pathogenicity and mortality. In this review, we summarize the history of NADC34-like strains in China and clarify the prevalence, genomic characteristics, restriction fragment length polymorphisms, recombination, pathogenicity, and vaccine status of this strain in China. In so doing, this study aims to provide a basis for the further development of prevention and control measures targeting the NADC34-like strain.

Toxoplasma gondii is a worldwide distributed zoonotic pathogen that threatens public health. However, there have been limited data for T. gondii infection in wild rats (Rattus norvegicus) in China. In the present study, a total of 227 wild rats were captured from three mink farms to investigate T. gondii infection in Shandong Province, eastern China. The DNA was extracted from 25 mg rats\' brain tissues and subjected to a PCR amplification by targeting to the T. gondii B1. In 227 wild rat samples, 18 samples (7.93%) were positive for T. gondii. Then, the positive samples were further genotyped based on eight genetic markers, including eight nuclear loci (SAG1, 5\'-SAG2, and 3\'-SAG2, alternative SAG2, SAG3, GRA6, c29-2, and L358) and an apicoplast locus (Apico) by using the multilocus PCR-restriction fragment length polymorphism technology. Of these samples, eight were genotyped at nine nuclear loci, and two were genotyped at eight nuclear loci, forming three known genotypes (ToxoDB no. 43, ToxoDB no. 91, and ToxoDB no. 189) and two new genotypes. The closest ToxoDB genotypes were observed in wild rats, suggesting the differences in the population structure of the T. gondii between breed farm animals and wild rats. These data revealed the genetic variability of T. gondii in wild rats on mink farms in Shandong Province, with possible implication for public health.

The newly emerged sublineage 1.5 (NADC34-like) porcine reproductive and respiratory syndrome virus (PRRSV) has posed a direct threat to the Chinese pig industry since 2018. However, the prevalence and impact of NADC34-like PRRSV on Chinese pig farms is unclear. In the present study, we continuously monitored pathogens-including PRRSV, African swine fever virus (ASFV), classical swine fever virus (CSFV), pseudorabies virus (PRV), and porcine circovirus 2 (PCV2)-on a fattening pig farm with strict biosecurity practices located in Heilongjiang Province, China, from 2020 to 2021. The results showed that multiple types of PRRSV coexisted on a single pig farm. NADC30-like and NADC34-like PRRSVs were the predominant strains on this pig farm. Importantly, NADC34-like PRRSV-detected during the period of peak mortality-was one of the predominant strains on this pig farm. Sequence alignment suggested that these strains shared the same 100 aa deletion in the NSP2 protein as IA/2014/NADC34 isolated from the United States (U.S.) in 2014. Phylogenetic analysis based on open reading frame 5 (ORF5) showed that the genetic diversity of NADC34-like PRRSV on this farm was relatively singular, but it had a relatively high rate of evolution. Restriction fragment length polymorphism (RFLP) pattern analysis showed that almost all ORF5 RFLPs were 1-7-4, with one 1-4-4. In addition, two complete genomes of NADC34-like PRRSVs were sequenced. Recombination analysis and sequence alignment demonstrated that both viruses, with 98.9% nucleotide similarity, were non-recombinant viruses. This study reports the prevalence and characteristics of NADC34-like PRRSVs on a large-scale breeding farm in northern China for the first time. These results will help to reveal the impact of NADC34-like PRRSVs on Chinese pig farms, and provide a reference for the detection and further prevention and control of NADC34-like PRRSVs.

OBJECTIVE: The aim of this work was to investigate three different mutations; Fec-B, FecXG, Fec-GH at three candidate genes; Bone morphogenetic protein receptor IB, Bone morphogenetic protein 15 and Growth Differentiation Factor 9, respectively, in six sheep breeds reared in Egypt namely; Rahmani, Barki, Rahmani X Barki cross, Awassi, Awassi X Suffolk cross, and Ossimi and their association with litter size.
RESULTS: Genomic DNA of 132 sheep was investigated for the Fec-B, FecXG, and Fec-GH mutations by Restriction Fragment Length Polymorphism, Single-Stranded Conformation Polymorphism and DNA sequencing. The results revealed that all breeds did not carry Fec-B mutation. On the other side, the mutations of FecXG, and Fec-GH were detected in Rahmani, and Rahmani X Barki cross which is associated with the high twinning rate/litter size of Rahmani (1.28) and Rahmani X Barki cross (1.22). While, the average litter size for other breeds had almost a constant values rate over six parities, ranging between 1.00 and 1.04.

OBJECTIVE: A total of 205 animals from four Egyptian livestock species; cattle (n = 18), buffaloes (n = 12), sheep (n = 150) and goats (n = 25) were used in this study to detect polymorphism and perform comparative analysis for IGFBP-3 gene using DNA sequencing and (PCR-RFLP).
RESULTS: The amplified fragments were found to be of length 654 bp in sheep, 651 bp in cattle and 655 bp in buffalo. For Falahy goats, PCR was performed to amplify a 316 bp fragment from exon 2 of the IGFBP-3 gene. The digestion of 654 bp with HaeIII restriction enzyme yielded a single restriction pattern for goats, while for cattle, 3 genotypes were identified; (AA), (AB), and (BB). Moreover, for buffalo one genotype (AA) only was found with HaeIII and TaqI restriction enzymes, separately. Also, the digestion profile for goats with HaeIII revealed one pattern only. Nucleotide sequencing of the amplified fragments of IGFBP-3 gene in sheep, cattle, buffalo, and goat was submitted to the NCBI GenBank (Accession no. MG738671.1, MG738673.1, MG738674.1, and MG738672.1, respectively). The nucleotide sequencing analysis indicated similarity percentages in IGFBP-3 gene fragments of 88.54, 89.63 and 95.06% between \"sheep and cattle\", \"sheep and buffalo\", and \"cattle and buffalo\", respectively.

Molecular markers play more and more important role in population genetic and phylogenetic studies; choice of marker systems for a particular study has become a serious problem. These marker systems have different advantages and disadvantages, so it is imperative to keep in mind all the pros and cons of the technique while selecting one for the problem to be addressed.Here, we concisely introduced three molecular marker techniques, namely SSR, ISSR, and RFLP. We elaborated their properties such as reliability, simplicity, cost-effectiveness, and speed, in addition to data analysis of genetic diversity. We have outlined here the whole methodology of these techniques.

OBJECTIVE: To report presence of Leishmania major in Khyber Pakhtunkhwa of Pakistan, where cutaneous leishmaniasis (CL) is endemic and was thought to be caused by Leishmania tropica only.
METHODS: Biopsy samples from 432 CL suspected patients were collected from 3 southern districts of Khyber Pakhtunkhwa during years 2011-2016. Microscopy on Giemsa stained slides were done followed by amplification of the ribosomal internal transcribed spacer 1 gene.
RESULTS: Leishmania amastigotes were detected by microscopy in 308 of 432 samples (71.3%) while 374 out of 432 samples (86.6%) were positive by ribosomal internal transcribed spacer 1 PCR. Subsequent restriction fragment length polymorphism confirmed L. tropica in 351 and L. major in 6 biopsy samples.
CONCLUSIONS: This study is the first molecular characterization of Leishmania species in southern Khyber Pakhtunkhwa. It confirmed the previous assumptions that anthroponotic CL is the major CL form present in Khyber Pakhtunkhwa province. Furthermore, this is the first report of L. major from a classical anthroponotic CL endemic focus identified in rural areas of Kohat district in southern Khyber Pakhtunkhwa.

The Gambierdiscus genus is a group of benthic dinoflagellates commonly associated with ciguatera fish poisoning (CFP), which is generally found in tropical or sub-tropical regions around the world. Morphologically similar species within the genus can vary in toxicity; however, species identifications are difficult or sometimes impossible using light microscopy. DNA sequencing of ribosomal RNA genes (rDNA) is thus often used to identify and describe Gambierdiscus species and ribotypes, but the expense and time can be prohibitive for routine culture screening and/or large-scale monitoring programs. This study describes a restriction fragment length polymorphism (RFLP) typing method based on analysis of the large subunit rDNA that can successfully identify at least nine of the described Gambierdiscus species and two Fukuyoa species. The software programs DNAMAN 6.0 and Restriction Enzyme Picker were used to identify a set of restriction enzymes (SpeI, HpyCH4IV, and TaqαI) capable of distinguishing most of the known Gambierdiscus species for which DNA sequences were available. This assay was tested using in silico analysis and cultured isolates, and species identifications of isolates assigned by RFLP typing were confirmed by DNA sequencing. To verify the assay and assess intra-specific heterogeneity in RFLP patterns, identifications of 63 Gambierdiscus isolates comprising ten Gambierdiscus species, one ribotype, and two Fukuyoa species were confirmed using RFLP typing, and this method was subsequently employed in the routine identification of isolates collected from the Caribbean Sea. The RFLP assay presented here reduces the time and cost associated with morphological identification via scanning electron microscopy and/or DNA sequencing, and provides a phylogenetically sensitive method for routine Gambierdiscus species assignment.

A great deal of evidence demonstrates that a strongly clonal population structure of Toxoplasma gondii strains exists in humans and animals in North America and Europe, while the strains from South America are genetically separate and more diverse. Potential differences in virulence between different strains mean that an understanding of strain diversity is important to human and animal health. However, to date, only one predominant genotype, ToxoDB#9 (Chinese I), and a few other genotypes, including ToxoDB#205, have been identified in China. By using DNA sequence-based phylogenetic analyses, we have re-evaluated the population structure of T. gondii strains collected from China and compared them with other global strains. Based on phylogenetic analysis of restriction fragment length polymorphisms, multilocus sequence typing and intron sequences from T. gondii, we propose that the Chinese isolates described as Chinese I are divided into two groups called Chinese I and Chinese III. Our results demonstrate that significant differences were found in mouse mortality caused by some Chinese strains, and also the archetypal I, II, III strains in mice. Furthermore, a comparison of cyst loading in the brains of infected rats showed some Chinese strains to be capable of a high degree of cyst formation. Furthermore we show that genotyping using neutral genetic markers may not be a useful predictor of pathogenic phenotypes.

BACKGROUND: Phytoplasmas are always associated with symptoms in host plants such as stunting of stems, witches\'-broom, yellowing of leaves, formation of sterile-deformed flowers, virescence and phyllody. Recently also symptom of fasciation was reported associated with phytoplasma presence. In the present work, China ixeris fasciation was observed associated with phytoplasmas in Guanzhong Area, Shaanxi, China.
RESULTS: Phytoplasma-like bodies were observed under transmission electron microscope in stem tissues of symptomatic samples. The 16S rRNA operon and tuf genes from phytoplasmas were amplified by PCR assays. Phylogenetic trees were calculated respectively based on sequences data of these two genes. The pattern of restriction fragment length polymorphism (RFLP) was generated via digesting the PCR products of 16S rRNA gene with eight restriction enzymes.
CONCLUSIONS: The presence of phytoplasma in China ixeris exhibiting fasciation symptom was confirmed by the results of TEM observation and PCR testing. Based on sequence data, phylogeny analysis and actual restriction fragment length polymorphism (RFLP) analysis, the associated phytoplasma was classified as related to 16SrI-C subgroup. This was the first record of phytoplasmas in China ixeris.