Propagation of Asian isolates of canine distemper virus (CDV) in hamster cell lines

<p>Abstract</p> <p>Backgrounds</p> <p>The aim of this study was to confirm the propagation of various canine distemper viruses (CDV) in hamster cell lines of HmLu and BHK, since only a little is known about the possibility of propagation of CDV in rodent cells irrespective of their epidemiological importance.</p> <p>Methods</p> <p>The growth of CDV in hamster cell lines was monitored by titration using Vero.dogSLAMtag (Vero-DST) cells that had been proven to be susceptible to almost all field isolates of CDV, with the preparations of cell-free and cell-associated virus from the cultures infected with recent Asian isolates of CDV (13 strains) and by observing the development of cytopathic effect (CPE) in infected cultures of hamster cell lines.</p> <p>Results</p> <p>Eleven of 13 strains grew in HmLu cells, and 12 of 13 strains grew in BHK cells with apparent CPE of cell fusion in the late stage of infection. Two strains and a strain of Asia 1 group could not grow in HmLu cells and BHK cells, respectively.</p> <p>Conclusion</p> <p>The present study demonstrates at the first time that hamster cell lines can propagate the majority of Asian field isolates of CDV. The usage of two hamster cell lines suggested to be useful to characterize the field isolates biologically.</p

Isolation and Molecular Detection of Pathogenic Vibrio Species among Economic Fish from Red Sea in Egypt

Peer reviewedPublisher PD

Prevalence of Toxigenic and Methicillin Resistant Staphylococci in Poultry Chain Production

oai:ojs.pkp.sfu.ca:article/1Staphylococci are a worldwide cause of human and animal infection and are considered to be of the most common causes of infections in birds. Enterotoxins produced by some staphylococcal species were recognized as a causative agent of staphylococcal food poisoning (SFP). Only enterotoxins produced by Staphylococcus aureus were as yet well characterized. Much less is known about&nbsp;enterotoxigenic&nbsp;potential&nbsp;of&nbsp;coagulase-negative&nbsp;species of genus Staphylococcus (CNS). It has been reported that&nbsp;enterotoxigenic&nbsp;CNS strains have been associated with human and animal infections and food poisoning. Samples collected from chicken production cycle (un hatched eggs, baby chicks, broilers, chicken meat and table eggs) in Luxor, Egypt were tested to investigate the presence of Staphylococcus species and detection of their enterotoxines genes with more special attention for detection of methicillin resistance gene (mec A). Samples were tested for S. aureus and CNS on the basis of cultural and biochemical properties and confirmed by PCR amplification of 16S rRNA and clfa gene. Results showed that the presence of Staphylococci were 50/150 (33.3%), 14% of the samples were S. aureus (21/150), while, 19.33% were CNS (29/150). mecA gene was detected in 66.7% and 51.7% among S. aureus and CNS respectively. Enterotoxins genes (seb, sec and see) were found in 5 (23.8%) of S. aureus with a percent of (9.5%) for seb and sec and (4.8%) for see, while sec and see were found in 6 (20.6%) of CNS.&nbsp; With a percent (10.3%) for each. &nbsp

The Asia 2 specific signal peptide region and other domains in fusion protein genes characterized Asia 1 and Asia 2 canine distemper viruses

<p>Abstract</p> <p>Background</p> <p>Although the presence of Asia 2 group of canine distemper virus (CDV) was known by the sequencing and phylogenetic analysis of hemagglutinin (H) gene, the fusion (F) protein gene sequence of Asia 2 group had not been identified. So, the sequence analysis of F gene was carried out to elucidate the genotypic varaitons among Asian isolates.</p> <p>Results</p> <p>The phylogenetic analysis of F and H gene sequences from fourteen CDV isolates obtained from diseased dogs in Japan and Thailand indicated that the F genes had a new initiation codon and extra 27 nucleotides upstream of the usual open reading frame (ORF) and the F proteins had extra 9 amino acids at the N-terminal position only in Asia 2 isolates. On the contrary, the Asia 1 isolates had three extra putative N-glycosylation sites (two sites in the signal peptide region and one site in the F1 region) except for two strains of Th12 and Ac96I (two sites in signal peptide region) adding to four putative N-glycosylation sites that were conserved among all Asian isolates and Onderstepoort strain. In addition to this difference in N-glycosylation sites, the signal peptide region had a great diversity between Asia 1 and Asia 2 isolates. Also, characteristic amino acids were detected for some strains.</p> <p>Conclusion</p> <p>Asia 2 isolates were distinguished from other CDV lineages by the extra 27 nucleotide sequence. The signal peptide region of F gene gives a remarkable differentiation between Asia 1 and Asia 2 isolates. Strains Th12 and Ac96I were differentiated from other Asia 1 strains by the F protein glycosylation sites.</p

Molecular Characterization of Biofilm Producing Genes in Salmonellae Isolated from Chicken

Salmonella enterica considered one of the most important food-borne pathogen. Biofilm formation considered one of the main problems related to S. enterica, in this study, biofilm formation, colony morphotype, cellulose and curli production genes of 19 Salmonella isolates were tested. The results showed that 85% of isolates produced strong biofilm and 15% of isolates produced moderate biofilm on polystyrene plate with 1/20 diluted TSB. Different colony morphotypes expressed saw, sbam, and rdar morphotype when cultivated on LB containing Congo red for monitoring cellulose and curli production. All S. enterica strains possess adrA, csgD and gcpA genes using PCR. Thus in this study all Salmonella isolates formed biofilm so they give increased tolerance for antimicrobial agents and disinfectant, which results in difficulty in the treatment of diseases and causing many problems in food industry as it becomes a persistent of source of contamination

Genetic characterization of H5N2 influenza viruses isolated from wild birds in Japan suggests multiple reassortment

Low-pathogenic avian influenza viruses (LPAIVs) of the H5 subtype can mutate to highly pathogenic forms, potentially destabilizing the poultry industry. Wild migratory birds are considered a natural reservoir of LPAIVs capable of dispersing both high- and low-pathogenic forms of the virus. Therefore, surveillance and characterization of AIV in wild birds are essential. Here, we report on the isolation and genetic characterization of 10 AIVs of the H5N2 subtype obtained through surveillance in Hokkaido, Japan, during 2009 and 2011. Full-genome sequencing revealed that the H5 and N2 genes of these isolates are all closely related to each other, belonging to the Eurasian avian-like lineage, but they are unrelated to H5 highly pathogenic strains of clade 2.3.4.4. The internal genes of the isolates were found to be diverse, consistent with our hypothesis that these H5N2 strains have undergone multiple reassortment events. Even though all of the H5N2 isolates were characterized as LPAIV based on the amino acid sequences at the HA cleavage site, this analysis demonstrates a diverse pool of precursors that may seed future outbreaks in poultry and possible human transmissions, suggesting the need for high-quality surveillance.Japan Society for the Promotion of Science. Grant-in-Aid for the Bilateral Joint ProjectsHeiwa Nakajima FoundationNational Institute of Allergy and Infectious Diseases (U.S.) (contracts HHSN266200700009C and HHSN266200700007C

Genetic characterization of a rare H12N3 avian influenza virus isolated from a green-winged teal in Japan

This study reports on the genetic characterization of an avian influenza virus, subtype H12N3, isolated from an Eurasian green-winged teal (Anas crecca) in Japan in 2009. The entire genome sequence of the isolate was analyzed, and phylogenetic analyses were conducted to characterize the evolutionary history of the isolate. Phylogenetic analysis of the hemagglutinin and neuraminidase genes indicated that the virus belonged to the Eurasian-like avian lineage. Molecular dating indicated that this H12 virus is likely a multiple reassortant influenza A virus. This is the first reported characterization of influenza A virus subtype H12N3 isolated in Japan and these data contribute to the accumulation of knowledge on the genetic diversity and generation of novel influenza A viruses.National Institute of Allergy and Infectious Diseases (U.S.) (Contracts HHSN266200700009C and HHSN266200700007)Japan Society for the Promotion of Science. Grant-in-Aid for the Bilateral Joint ProjectsHeiwa Nakajima Foundatio

Class II HMG-CoA Reductase Inhibitors targeting Methicillin-Resistant Staphylococcus pseudintermedius

Staphylococcus pseudintermedius is a component of the normal flora of companion animals that contributes to opportunistic infections in dogs. Clinical isolates of S. pseudintermedius (chiefly methicillin-resistant S. pseudintermedius (MRSP)) have been identified that exhibit resistance to nearly all antibiotic classes. There is a need for new antibiotics that target novel pathways within resistant pathogens such as MRSP. A possible novel antibacterial target in Gram-positive cocci is class II HMG-CoA reductase (HMGR), a key enzyme present in the mevalonate pathway that is essential for bacterial survival. In this study we examined novel synthetic compounds that are potent inhibitors of bacterial HMGRs. The compounds inhibited growth, in low micromolar concentration, of clinical isolates of methicillin-sensitive S. pseudintermedius (MSSP) and MRSP via the broth microdilution assay. The MTS assay confirmed the most potent compound (6) wasnot toxic to different mammalian cell lines (up to 128 µM). A time-kill assay revealed this compound rapidly eradicates a high inoculum of MRSP within two hours. This study provides evidence that compound 6 is a promising agent that warrants further investigation as a novel treatment option for MRSP infections

Molecular characterization of avian influenza viruses (H5N2, H5N8, H5Nx and H9N2) isolated from chickens and ducks in the South of Egypt 2020 – 2021

This study was conducted to investigate the epidemiological situation of avian influenza viruses (AIV) and the molecular identification of the different AIV subtypes circulating among chickens and duck farms in South Egypt. A total of 143 samples were collected from chicken and duck farms in Qena (n = 105) and Luxor (n=38) governorates during 2020. The organs and swabs were collected from diseased chickens and healthy ducks. The viruses were isolated in embryonated chicken eggs (ECEs) and their propagation was confirmed by hemagglutination test (AHT) and molecular detection of matrix gene by reverse transcription polymerase chain reaction (RT-PCR). AIV subtypes were identified by RT-PCR and specific primers. Phylogenetic analysis of sequenced partial H5, N2, and N8 genes was performed. The results revealed that 15 AIVs were subtyped to 2 H5N2, 2 H5N8, 8 H5Nx, and 2 H9N2. While an isolate could not be subtyped by used primers. The H5-based evolutionary tree of 4 isolates revealed their categorization with the 2.3.4.4b clade with close relation to H5N8 isolates from Egypt in 2021 and Kazakhstan in 2020. In conclusion, the occurrence of H5 and H9 viruses pays attention to a public health concern. Also, non-identified HxNx reveals a new AIV HA and NA subtype may be present among chickens

Detection of Biofilm and some Enterotoxins of Staphylococcus aureus Isolates in Ice Cream

Staphylococcus aureus is the most bacteria that have ability to form a biofilm and secret different types of enterotoxins that cause food poisoning in humans. Biofilms is a community of microorganisms encased in a matrix of extracellular polysaccharide (slime), called polysaccharide intercellular adhesion (PIA). They have related to a diversity of chronic and persistent infections. This study aims to detect the ability of S. aureus isolated from ice cream to form biofilm by Congo red agar (CRA), microliter plate, and PCR and the ability of S. aureus to produce enterotoxins by PCR. 15 S. aureus isolates were grown on CRA and microtiter plate method then subjected for detection of icaA and icaD genes by PCR and for the presence of enterotoxins genes (sea, seb, sec, sed, and see) which are responsible for S. aureus biofilm formation and Staphylococcus food poisoning. 73.3% of the isolates were biofilm producers on Congo red agar, 60% of the isolates were positive for biofilm production using microtiter plate method and by PCR technique, all the isolates 100% had icaD gene and 86.6% had icaA gene. The enterotoxin seb gene was detected in 5 (33.3%) S. aureus isolates, the enterotoxin see gene was detected in 4 (26.6%) S. aureus isolates while sea, seb and sed gens were not detected in any S. aureus isolates. In conclusion all aureus isolates were positive for icaD gene and some of S. aureus isolates were positive for icaA gene which are responsible for biofilm formation and some S. aureus isolates were positive for enterotoxin B and enterotoxin E, which responsible for food intoxication so the ice-cream considered a potential source for food intoxication and persistent infection caused by S. aureus