Divergent evolution of Corynebacterium diphtheriae in India: An update from National Diphtheria Surveillance network.

Diphtheria is caused by a toxigenic bacterium Corynebacterium diphtheria which is being an emerging pathogen in India. Since diphtheria morbidity and mortality continues to be high in the country, the present study aimed to study the molecular epidemiology of C. diphtheriae strains from India. A total of 441 diphtheria suspected specimens collected as part of the surveillance programme between 2015 and 2020 were studied. All the isolates were confirmed as C. diphtheriae with standard biochemical tests, ELEK's test, and real-time PCR. Antimicrobial susceptibility testing for the subset of isolates showed intermediate susceptibility to penicillin and complete susceptible to erythromycin and cefotaxime. Isolates were characterized using multi locus sequence typing method. MLST analysis for the 216 C. diphtheriae isolates revealed major diversity among the sequence types. A total of 34 STs were assigned with majority of the isolates belonged to ST466 (30%). The second most common ST identified was ST405 that was present in 14% of the isolates. The international clone ST50 was also seen. The identified STs were grouped into 8 different clonal complexes (CC). The majority belongs to CC5 followed by CC466, CC574 and CC209, however a single non-toxigenic strain belongs to CC42. This epidemiological analysis revealed the emergence of novel STs and the clones with better dissemination properties. This study has also provided information on the circulating strains of C. diphtheriae among the different regions of India. The molecular data generated through surveillance system can be utilized for further actions in concern.

Synchronous oral squamous cell carcinomas with unusual histopathological feature.

Patients with head and neck carcinomas have high incidence (2-3% per year) of second primary lesions. Although "field cancerization" was first described in oral squamous cell carcinomas (OSCCs), only few studies have been concentrated on multifocal primary squamous cell carcinomas in the oral cavity. Synchronous carcinomas are defined as second neoplasms at the same time or within 6 months period of primary lesions. After this period, they are considered as metachronous neoplasms. Tumors composed exclusively or in large part of clear cells are rare in salivary glands, jaws and oral mucosa. OSCCs composed of clear cells or clear cell variant are not documented in the English literature. We present an unusual case of synchronous OSCCs composed predominantly of clear cells.

Efficacy and safety of USG-guided ethanol sclerotherapy in cystic thyroid nodules.

OBJECTIVE: To study the effectiveness and safety of USG-guided ethanol sclerotherapy in cystic thyroid nodules. MATERIALS AND METHODS: USG of the thyroid gland was performed in 54 patients suspected to have a thyroid nodule on clinical examination. All patients with a predominantly cystic nodule (i.e., when> 2/3 rd of the nodule was cystic) were included in the study. Ethanol was injected into the cyst under USG guidance. The amount of ethanol injected was about 50% of the amount of aspirated fluid. Follow-up USG was done every month for 3 months; ethanol was re-injected when there was no significant reduction in the cyst volume. The initial cyst volume was compared with the final volume; statistical significance was assessed using the paired t-test. RESULTS: USG revealed predominant cystic nodules in 16 of the 54 patients. Fifteen patients were selected for the study. Following ethanol sclerotherapy, four out of the 15 patients (26.6%) showed complete disappearance of the cyst and nine (60%) showed significant reduction in the cyst volume (i.e., reduction of cyst volume by >/=50% of initial volume). Only two patients did not show significant reduction in cyst volume; both these patients had nodules with an initial volume of >/=20 cc. There were no complications attributable to ethanol injection during follow-up. CONCLUSION: Ethanol sclerotherapy is an effective and safe treatment for benign cystic thyroid nodules with volumes of < 20 cc. Cystic nodules with volume> 20 cc may need more number of alcohol injections and longer follow-up.