Growth kinetics of an Indian isolate of highly pathogenic porcine reproductive and respiratory syndrome virus in MARC-145 cells.

The aim of the present study was to understand the replication kinetics of an Indian isolate of highly pathogenic porcine reproductive and respiratory syndrome (PRRS) virus (Ind-297221) in MARC-145 cells infected at different multiplicity of infection (MOI) of 1.0, 0.1, 0.01 and 0.001. PRRSV titre in the infected cell fraction and the culture supernatant harvested at different intervals (12, 36, 48, 72, 96 and 120 h) post infection (hpi) was estimated by immunoperoxidase monolayer assay. Viral RNA copy numbers were quantified by TaqMan RT-PCR. PRRS virus could be detected first in intracellular fraction at 12 hpi in cells infected at 1.0 MOI, whereas in the extracellular fraction, earliest detection was at 36 hpi. Highest PRRSV titre of 1.3 × 105.0 TCID50/mL was achieved in 0.01 and 0.001 MOI groups at 96 hpi. Infection with 0.01 MOI resulted in the maintenance of maximum titre up to 120 hpi. The maximum viral copy numbers observed was 3.15 × 107.0 in 0.1 MOI group at 120 hpi in culture medium. The results of the study showed that MARC-145 cells infected with Indian PRRSV at 0.01 MOI and harvested in 96-120 hpi was found to be optimum for obtaining maximum virus yield and hence can be used for bulk propagation of the virus.

Perception of risk factors at work associated with musculoskeletal symptoms in dental students of Melaka, Malaysia: A cross-sectional study.

BACKGROUND: Dental professionals have been reported to be constantly exposed to work-related musculoskeletal disorders with symptoms often started as early as the student phase. Risk perception may play an important role in modifying risk at work. OBJECTIVE: To assess the influence of gender, academic level, and the presence of painful symptoms on the perception of risk factors at work contributing to musculoskeletal symptoms among dental students of Melaka, Malaysia. METHODS: A cross-sectional survey of 183 clinical year dental students based on a convenience sample. The data were collected using the Nordic Musculoskeletal Questionnaire and Job Factor Questionnaire for assessment of musculoskeletal symptoms and risk factors at work respectively. Study data were evaluated using percentage, median, Cochran's Q test, Bonferroni correction, multiple linear regression analysis and Mann-Whitney U Test. The analysis was interpreted considering a 95 % confidence interval and significant level at P < 0.05. RESULTS: Dental students reported a high prevalence (86.9 %) of musculoskeletal symptoms mostly affected the neck, shoulder, lower and upper back body regions. No significant difference in perception was found with the gender. A significant (P < 0.05) higher perception was observed in fourth-year students. The presence of painful symptoms was significantly (P < 0.05) associated with working in the same position, prolonged duration of work and use of tools. CONCLUSIONS: Priority in implementing ergonomic education throughout the training in the dental schools should be considered to improve perception and reduce musculoskeletal disorders associated with the dental profession.

Genetic characterization of African swine fever virus from domestic pigs in India.

African swine fever (ASF) is the most dreaded disease of pigs, which can cause mortality of up to 100%. Following disease outbreaks with high mortality in pigs in two states of north-east India, namely Arunachal Pradesh and Assam in early 2020, we confirmed the first occurrence of African swine fever (ASF) in domestic pigs in India by real-time PCR, virus isolation and nucleotide sequencing. Genetic analyses in three independent genomic regions (B646L gene encoding the p72 protein, E183L gene encoding the p54 protein and the central variable region (CVR) of B602L gene) showed that the Indian ASF viruses are similar to the post-2007-p72-genotype II viruses reported from Asia and Europe, suggesting the transboundary expansion of ongoing ASF outbreaks in the region.

Detection of coinfection of a divergent subgroup of genotype I Japanese encephalitis virus in multiple classical swine fever virus outbreaks in pigs of Assam, India.

A retrospective investigation of pig tissue samples from different classical swine fever virus (CSFV) outbreaks was undertaken employing RT-PCR for possible coinfection with other swine viruses. Four samples from three different outbreaks were found to be coinfected with Japanese encephalitis virus (JEV). Phylogenetic analysis was done based on complete E gene sequenced from all four coinfected samples. This revealed a new introduction of a divergent subgroup of JEV genotype I in India. This is the first report of detection of coinfection of JEV and CSFV in pigs and the first incidence of JEV genotype I in pigs in India.

Lumpy skin disease (LSD) outbreaks in cattle in Odisha state, India in August 2019: Epidemiological features and molecular studies.

Lumpy skin disease (LSD) caused by lumpy skin disease virus (LSDV) inflicts significant economic losses in cattle production with impact on livelihoods of smallholders. This study reports the first occurrence of LSD in cattle in India and analyses epidemiological and genetic characterization data from LSD outbreaks in five districts of Odisha state in August 2019. In all, 182 of 2,539 cattle were affected with an apparent morbidity rate of 7.1% and no mortality. Out of 102 samples from 60 LSD suspected and 17 asymptomatic in-contact cattle tested, 29.87% cattle were positive by capripoxvirus generic PCR and 37.66% were positive by LSDV real-time PCR. All the in-contact cattle tested were negative for LSDV. Among affected cattle, LSDV genome was detected more in scabs (79.16%) than blood (31.81%) and frozen bull semen (20.45%). Differential diagnosis by PCR was negative for pseudo-LSD, buffalopox, cowpox, pseudo-cowpox and bovine papular stomatitis. Five selected PCR and real-time PCR-positive LSDV DNA were sequenced in three genomic regions, P32 (LSDV074), F (LSDV117) and RPO30 (LSDV036). Phylogenetic analysis based on partial P32 and F gene sequences and complete RPO30 gene sequences showed that all the five Indian LSDV strains were identical and clustered with other field strains of LSDV circulating globally. However, the F and RPO30 gene sequence analyses revealed that Indian LSDV strains are genetically closer to the South African NI2490/KSGP-like strains than the strains detected in Europe, which was rather surprising. The present study established the existence of LSDV in India and involvement of LSDV field strains in the outbreaks. Additionally, we provided evidence of LSDV shedding in semen of naturally infected bulls. Further studies are required to determine the source of LSD introduction, extent of spread, modes of transmission and impact on dairy cattle production in India and effective control measures must be undertaken urgently.

Oral Health and Erectile Dysfunction.

Ample evidence strongly supports the fact that periodontal disease is a major risk factor for various systemic diseases namely cardio-vascular disease, diabetes mellitus, etc. Recently, investigators focussed on exploring the link between chronic periodontitis (CP) and erectile dysfunction (ED) by contributing to the endothelial dysfunction. Both the diseases share common risk factors. Various studies conducted in different parts of the world in recent years reported the evidence linking this relationship as well as improvement in ED with periodontal treatment. Systemic exposure to the periodontal pathogen and periodontal infection-induced systemic inflammation was thought to associate with these conditions. The objective of this review was to highlight the evidence of the link between CP and ED and the importance of oral health in preventing the systemic conditions.

Assessment and management of halitosis.

Halitosis is an unpleasant condition that may be the origin of concern not only for a possible health condition but also for frequent psychological alterations which may lead to social and personal isolation. The most frequent sources of halitosis that exist in the oral cavity include bacterial reservoirs such as the dorsum of the tongue, saliva and periodontal pockets. Volatile sulphur compounds (VSCs) are the prominent elements of oral malodour. Genuine halitosis and pseudo-halitosis should be in the treatment realm of dental practitioners. Clinical Relevance: Halitosis can be a symptom of underlying systemic disease, therefore the exact diagnosis and its source (oral or non-oral) is important in the proper approach to its management.

Development of a recombinant flagellin based ELISA for the detection of Clostridium chauvoei.

Blackleg, an economically important and highly fatal disease of ruminants, is caused by anaerobic bacillus, Clostridium chauvoei. Identification and differentiation of the causative agent is crucial for implementation of therapeutic and control measures in real time. Most of the diagnostic tests available for blackleg are PCR based, and only a couple of serological tests have been reported. In this study, we targeted flagellin, an important immunogenic protein of C. chauvoei, to develop a sandwich ELISA for detection of C. chauvoei. Sequence analysis of flagellin gene of related Clostridium species showed that central region of flagellin gene is unique to C. chauvoei. Hence, we cloned and expressed central region of flagellin in a prokaryotic expression system. Antiserum against recombinant flagellin was generated in rabbits and chickens. A sandwich ELISA was developed, in which rabbit anti-flagellin antibodies were used as capture antibodies and chicken anti-flagellin antibodies as detecting antibodies. The test was specific and sensitive in detection of up to 10(4) CFU/ml of C. chauvoei. This study shows that assay developed can be used for detection of C. chauvoei in suspected samples.

Virulence gene profiling and antibiotic resistance pattern of Indian isolates of Pasteurella multocida of small ruminant origin.

Pasteurellosis in small ruminants affects the livelihood of small and marginal farmers of India. The present study was undertaken to understand the trends in gene carriage and antibiotic resistance pattern of Pasteurella multocida isolates recovered from small ruminants over a period of 10 years in India. A total of 88 P. multocida isolates of small ruminant origin were subjected to virulence gene profiling for 19 genes by PCR and antibiogram study employing 17 different antibiotics. Virulence genes like exbB, exbD, tonB, oma87, sodA, sodC, nanB and plpB (100% prevalence) and ptfA and hsf-2 (>90% prevalence) were found to be uniformly distributed among isolates. Unexpectedly, a very high prevalence (95.45%) of pfhA gene was observed in the present study. Dermonecrotoxin gene (toxA) was observed in 48.9% of isolates with highest occurrence among serotype A isolates and interestingly, one of each isolate of serotype B and F were found to carry this gene. Antimicrobial susceptibility testing revealed 17.04% isolates to be multidrug resistant. Amongst all the antibiotics tested, most of the P. multocida isolates were found to be susceptible to enrofloxacin and chloramphenicol. This study highlights novel epidemiological information on frequency and occurrence of virulence genes among Indian isolates from small ruminants.

Black triangle dilemma and its management in esthetic dentistry.

In recent years, clinician and dentist's esthetic demand in dentistry have increased rapidly, driven by an enhanced awareness of beauty and esthetics. The ultimate goal in modern restorative dentistry is to achieve "white" and "pink" esthetics in esthetically important zones. "White esthetics" is the natural dentition or the restoration of dental hard tissues with suitable materials. "Pink esthetics" refers to the surrounding soft-tissues, which includes the interdental papilla and gingiva that can enhance or diminish the esthetic result. Reconstruction of the lost interdental papilla is one of the most challenging and least predictable problems. Restoration and maintenance of these tissues with adequate surgical and prosthetic techniques are a real challenge in modern esthetic dentistry. Treatment of marginal tissue recession, excessive gingival display, deficient ridges, ridge collapse, and esthetic defects around teeth and implants are some of the esthetic problems associated with the interdental papilla that have to be corrected in todays scenario which has been discussed in this review.

Evaluation and comparison of native and recombinant LipL21 protein-based ELISAs for diagnosis of bovine leptospirosis.

A 21-kDa leptospiral lipoprotein (LipL21) was evaluated for its diagnostic potential to detect bovine leptospirosis by ELISA. Both native LipL21 (nLipL21) and recombinant LipL21 (rLipL21) proteins were tested and compared regarding diagnostic efficiency, and no statistically significant difference was observed. The sensitivity of rLipL21 ELISA for 62 microscopic agglutination test (MAT) positive sera was 100% and the specificity with 378 MAT negative sera was 97.09%. Thus, rLipL21 protein-based ELISA could be used as an alternative to MAT for the diagnosis of bovine leptospirosis.

Clinical and radiographic evaluation of Nano-crystalline hydroxyapatite bone graft (Sybograf) in combination with bioresorbable collagen membrane (Periocol) in periodontal intrabony defects.

BACKGROUND: Nanosized ceramics may represent a promising class of bone graft substitutes due to their improved osseointegrative properties. Nanocrystalline Hydroxyapatite (NcHA) bind to bone and stimulate bone healing by stimulation of osteoblast activity. The present study aims to explore the clinical and radiographical outcome of NcHA bonegraft (Sybograf(®)) with collagen membrane (Periocol(®)), in comparison with open flap debridement (OFD), in the treatment of intrabony periodontal defects. MATERIALS AND METHODS: A parallel-group, randomized, controlled clinical trial was designed to conduct the study. Eighteen intrabony defects in 14 systemically healthy patients aged between 25 to 65 years were randomly assigned to test and control group. The plaque index, gingival index, probing pocket depth (PPD), clinical attachment level (CAL), and gingival recession (REC) were recorded at baseline, and were reevaluated at 6 months. In addition to this, radiographic bone fill was assessed using digital software. At the test site, NcHA bone graft and collagen membrane was placed, whereas at the control site, only OFD was done. Recall appointments were made at 7 days, 30 days, and then at 3 months and 6 months. RESULTS: The data were subjected to statistical analysis using the Mann-Whitney 'U' Test and Wilcoxon signed rank sum test. In the control group, the mean reduction of PPD was 3.22±1.09 mm (P=0.007) and CAL gain was 2.77±1.09 mm (P=0.007). In the test group, the mean PPD reduction of 4.33±0.5 mm (P=0.006) and mean gain in CAL was 3.77±0.66 mm (P=0.006) at 6 months. The mean increase in REC was 0.55±0.72 mm (P=0.025) in test, and 0.44±0.52 mm (P=0.046) in control group. The mean gain in radiographic defect fill was 2.07±0.67 mm (P=0.008) in test and 0.91±0.21 mm (P=0.007) in control group. CONCLUSION: The nanocrystalline hydroxyapatite bone graft in combination with collagen membrane demonstrated clinical advantages beyond that achieved by OFD alone.

Nano-crystalline hydroxyapatite bone graft combined with bioresorbable collagen membrane in the treatment of periodontal intrabony defects: A randomized controlled clinical trial.

AIM: To evaluate the clinical outcome of nanocrystalline hydroxyapatite (NcHA) bonegraft (Sybograf(®)) in combination with collagen membrane (PerioCol(®)) compared with open flap debridement (OFD) only in the treatment of intrabony periodontal defects. MATERIALS AND METHODS: Eighteen intrabony defects in 16 systemically healthy patients aged between 25-65 years, were randomly assigned to test and control groups. The Plaque index, gingival index, probing pocket depth (PPD), clinical attachment level (CAL), and gingival recession were recorded at baseline, and were reevaluated at 6 months. In addition to this, radiographic bone fill was assessed using digital software. At the test site NcHA bone graft and collagen membrane was placed, whereas at the control site only, OFD was done. Recall appointments were made at 7(th) day, 1(st) month, 3(rd) month, and 6(th) month. RESULTS: The data were subjected to statistical analysis using the Mann-Whitney 'U' Test and Wilcoxon signed rank sum test. In the control group, the mean reduction of PPD was 3.22±1.09 mm and CAL gain was 2.78±1.09 mm. In the test group, the mean PPD reduction of 4.33±0.5 mm and mean gain in CAL was 3.78±0.66 mm at 6 months. The mean increase in gingival recession was 0.55±0.72 mm in test and 0.44±0.52 mm in control group. CONCLUSION: The NcHA bone graft in combination with collagen membrane demonstrated better clinical outcomes compared with OFD alone.

Identification of avian strains of Pasteurella multocida in India by conventional and PCR assays.

The prevalence of capsular and somatic serotypes were studied among 123 Pasteurella multocida strains isolated from chickens (n=94), ducks (22), quails (4), turkeys (2) and geese (1) from different geographical regions of India. All strains exhibited similar cultural and morphological characteristics. Ninety-two of the isolates belonged to serotype A:1, the most prevalent serotype, with serotypes A:3, A:1,3, D:3 and F:3 having two isolates each. Only one isolate was positive for serotypes A:4 and D:1. Twenty isolates were untyped. A multiplex capsular PCR assay generated amplicons of sizes approximately 460, approximately 1044, approximately 657 and approximately 854 bp in 106 isolates identified as capsular serotype-A, 15 in serotype D and two in serotype F. Capsular types B and E were not detected in any of the avian isolates studied. The present findings suggest that a multiplex capsular PCR assay may be suitable for the rapid initial identification serotypes P. multocida during epidemiological studies of fowl cholera.

Prevalent serotypes of Pasteurella multocida isolated from different animal and avian species in India.

Identification and estimation of the prevalence of Pasteurella multocida organisms in different animal and avian species in India during November 2000 to July 2003 was carried out. Out of 418 samples collected from different outbreaks suspected to be caused by P. multocida, a total of 206 bacterial cultures were identified as P. multocida on the basis of cultural, morphological and biochemical characteristics. All the 206 cultures were isolated from different domestic animal species (cattle, buffalo, sheep, goat, pig and rabbit), avian species (chicken, duck, quail, turkey, goose) and wild animals such as leopard and deer. Serotyping of P. multocida cultures revealed the presence of various serotypes (A:1, A:3, A:1,3, A:4, B:2, D:1 and -:1) among the livestock population. P. multocida polymerase chain reaction (PCR) assay applied on different forms of bacterial cultures (bacterial culture lysate, direct bacterial colony and mixed bacterial culture lysate) yielded an amplified product of approximately 460 bp specific for P. multocida. The results of PCR assay correlated well with conventional methods of identification. The present investigation revealed the presence of varied serotypes among livestock and PCR assay was found to be useful for rapid, sensitive and specific diagnosis of pasteurellosis in animals and avian species.

Isolation and characterisation of an Indian strain of Mycoplasma mycoides subsp. mycoides type LC from a case of caprine arthritis.

Isolation and characterisation of an Indian strain of Mycoplasma mycoides subsp. mycoides LC from a case of caprine arthritis is reported in the study. The isolate was identified based on biochemical, digitonin sensitivity and growth inhibition tests. The virulence of the organism was studied by pathogenicity test in mice and goat. The antigenic and genomic profile of the isolate was compared with that of the standard strain (Y-Goat). Using different sets of primers, polymerase chain reaction was employed for rapid detection of the strain.

Specific identification of Pasteurella multocida serogroup-A isolates by PCR assay.

A polymerase chain reaction (PCR) assay targeting the hyaC-hyaD gene was developed and used to identify strains of Pasteurella multocida belonging to serogroup-A. A set of serogroup-specific-PCR primers amplified a 564 bp product from genomic DNA prepared from bacterial cells or directly from bacterial colonies. This method detected as low as 10 ng of bacterial DNA and had a specificity of 100% for P. multocida serogroup-A. A nested PCR method yielded a single 374 bp product. All fifty isolates were also shown to be identical by restriction fragment length polymorphism (RFLP) analysis of the PCR products after digestion with BglII.

Antibiotic sensitivity patterns among Indian strains of avian Pasteurella multocida.

An investigation was carried out to study the antibiotic sensitivity of avian strains of Pasteurella multocida and to select an effective antimicrobial agent for control of avian pasteurellosis in India. A total of 123 strains of P. multocida recently isolated from different avian species (chicken, duck, turkey, quail, and goose), from different regions of India were subjected to antibiotic sensitivity tests using 20 different antibiotics. Absolute resistance was observed against sulfadiazine. The studies indicated that the strains were most sensitive to chloramphenicol (73.98%), followed by enrofloxacin (71.54%), lincomycin (64.23%), norfloxacin (61.79%) and doxycycline-HCl (56.91%). The majority of the strains were found to exhibit intermediate sensitivity. Chloramphenicol was selected and suggested for treatment. Antibiogram studies also revealed the emergence of multidrug-resistant strains of P. multocida among Indian poultry.