Catabolite control protein C contributes to virulence and hydrogen peroxide-induced oxidative stress responses in Listeria monocytogenes.

Listeria monocytogenes causes listeriosis, an infectious and potentially fatal disease of animals and humans. A diverse network of transcriptional regulators, including LysR-type catabolite control protein C (CcpC), is critical for the survival of L. monocytogenes and its ability to transition into the host environment. In this study, we explored the physiological and genetic consequences of deleting ccpC and the effects of such deletion on the ability of L. monocytogenes to cause disease. We found that ccpC deletion did not impact hemolytic activity, whereas it resulted in significant reductions in phospholipase activities. Western blotting revealed that the ΔccpC strain produced significantly reduced levels of the cholesterol-dependent cytolysin LLO relative to the wildtype F2365 strain. However, the ΔccpC mutant displayed no significant intracellular growth defect in macrophages. Furthermore, ΔccpC strain exhibited reduction in plaque numbers in fibroblasts compared to F2365, but plaque size was not significantly affected by ccpC deletion. In a murine model system, the ΔccpC strain exhibited a significantly reduced bacterial burden in the liver and spleen compared to the wildtype F2365 strain. Interestingly, the deletion of this gene also enhanced the survival of L. monocytogenes under conditions of H2O2-induced oxidative stress. Transcriptomic analyses performed under H2O2-induced oxidative stress conditions revealed that DNA repair, cellular responses to DNA damage and stress, metalloregulatory proteins, and genes involved in the biosynthesis of peptidoglycan and teichoic acids were significantly induced in the ccpC deletion strain relative to F2365. In contrast, genes encoding internalin, 1-phosphatidylinositol phosphodiesterase, and genes associated with sugar-specific phosphotransferase system components, porphyrin, branched-chain amino acids, and pentose phosphate pathway were significantly downregulated in the ccpC deletion strain relative to F2365. This finding highlights CcpC as a key factor that regulates L. monocytogenes physiology and responses to oxidative stress by controlling the expression of important metabolic pathways.

Molecular detection and phylogenetic analysis of Canine Parvovirus (CPV) in diarrhoeic pet dogs in Bangladesh.

Since its emergence, Canine Parvovirus type 2 (CPV-2) has been considered as a deadly pathogen in dogs with high mortality in puppies for its clinical gastroenteritis and severe haemorrhagic diarrhoea. Although several studies on CPV-2 were conducted in Bangladesh, molecular investigation is poorly understood. The aim of the study was molecular detection and phylogenetic analysis of CPV in diarrhoeic pet dogs. During Jan-July 2019, anal swabs were collected from 96 unvaccinated pet dogs with suspected CPV infection from Sylhet region of Bangladesh. The CPV infection was initially screened through rapid Immunochromatographic (IC) strip test, and then CPV-2 (VP2 gene) were detected by conventional PCR assay. Then the nucleotide sequence of amplified VP2 gene was compared with other CPV strains from GeneBank. Of the total samples, 17.7% (17/96) found positive in IC strip test, and 15.62% (15/96) were found positive in PCR assay by using primer pair P2 that detect original CPV-2 type. The IC test showed 100% sensitivity and 97.5% specificity with PCR. In sequence analysis, our isolates showed the highest 90.40% homology with the isolates of China and the USA. Our strains had also an evolutionary relationship with the other strains of CPV from China and India. This study demonstrates the presence of CPV-2 in Bangladesh and futher sequence analysis of more VP2 gene will help in details insight of the molecular and genetic evolution of CPV in Bangladesh.

Successful management of a kitten with chlorpyrifos and cypermethrin toxicosis with pralidoxime and atropine.

CASE SUMMARY: Organophosphates and pyrethroids have been widely used as agricultural and domestic insecticides. This case report describes a 3-month-old free-roaming female kitten, weighing 930 g, that developed hypersalivation, hypothermia, dyspnoea due to increased bronchial secretion, bradycardia, miosis and neurological signs, including restlessness, ataxia, disorientation, apparent hallucination, muscle twitching and seizures within 6 h of accidental ingestion of an insecticide containing chlorpyrifos (500 g/l) and cypermethrin (50 g/l). The kitten was treated empirically with intramuscular atropine and dexamethasone, and rectal diazepam. The history of insecticide exposure was obtained after 6 h of treatment and intramuscular 2-pyridine aldoxime methochloride (pralidoxime [2-PAM]) and atropine therapy was started 2 h later. Recovery was complicated by suspected aspiration, but there were no sequelae from the insecticide exposure and by 7 days post-ingestion the kitten was normal and playful. RELEVANCE AND NOVEL INFORMATION: To the best of our knowledge, this is the first report of successful management of chlorpyrifos and cypermethrin toxicosis in a cat in Bangladesh. This case report suggests that 2-PAM followed by atropine and other supportive therapy may be an effective strategy to manage a cat poisoned by chlorpyrifos and cypermethrin; however, expanded clinical trials are needed.

Prevalence and severity of gastro-intestinal parasites in buffalo calves at Sylhet division of Bangladesh.

Gastrointestinal (GI) parasites are one of the most widely recognized health problems of buffalo calves in Bangladesh. The study was undertaken to investigate the prevalence of GI parasitic infestation in buffalo calves at Sylhet division of Bangladesh. Fecal samples of 200 buffalo calves under 1 year of age (76 males and 124 females) were collected from Sylhet, Maulvibazar, Habiganj, and Sunamganj districts, and from each of the four regions, 50 samples were collected. Samples were examined through simple flotation, sedimentation, and McMaster techniques. The overall prevalence of GI parasites in Sylhet division was 65.5%. Among the samples, the highest prevalence of GI parasite was found in Sylhet (78%), followed by Sunamganj (68%), Maulvibazar (66%), and Habiganj (50%) districts. Among the identified GI parasites, the highest prevalence was observed in case of Neoascaris vitulorum (26.5%). The highest prevalence of GI parasite was observed in summer (69.84%), followed by rainy (69.62%) and winter (55.17%) seasons. Males and females were almost equally susceptible to GI parasitic infestation. Older calves (9-12 months, 77.14%) were most vulnerable to GI parasites. Egg per gram (EPG) of feces was additionally counted in the current study to know the severity of infestation. The range of EPG varied from 50 to 900 among the identified parasites. Among them, the highest count was found in the case of Neoascaris vitulorum (100-900). It may be concluded that aggregated policies and actions need to be taken to control the GI parasitic infestation in buffalo calves at Sylhet Division and elsewhere in developing countries like Bangladesh.

First molecular characterization and phylogenetic analysis of the VP2 gene of feline panleukopenia virus in Bangladesh.

Feline panleukopenia virus (FPV) is a highly contagious infectious pathogen of cats globally. However, there is no information on the molecular identification and characterization of FPV in Bangladesh. Here, 8.16% (8/98) and 18.37% (18/98) of diarrheic cats tested positive for FPV by an immunochromatography (IC) test and PCR, respectively. The IC test showed 44.44% sensitivity and 100% specificity in comparison with PCR. Our newly sequenced Bangladeshi FPV strain (MN826076) showed the highest (99.71%) sequence identity to strains from the United Arab Emirates (UAE). Strain MN826076 contained two characteristic amino acid variations in VP2 identifying it as an FPV strain: valine at position 103 and aspartic acid at position 323. Phylogenetically, the VP2 of strain MN826076 was found to be closely related to 19 FPV strains, sharing the same clade.