Jundishapur Journal of Microbiology
Volume:15 Issue: 8, Aug 2022

About 70% of individuals worldwide suffer from herpes simplex virus 1 (HSV-1). Several studies have reported that selenium and supernatant of probiotic bacteria are antiviral; nevertheless, their effect alone or synergistically on HSV-1 is unknown.

The present study aimed to evaluate the antiviral effects of Bacillus clausii supernatant, selenium (Se), and their combination on HSV-1.

After determining cytotoxicity by the MTT assay, selenium and B. clausii supernatants were added to HeLa cells 24 hours before (pre-infection treatment) and after (post-infection treatment) HSV-1 inoculation. After 47 hours of incubation at 37°C, the viral titer and expression levels of the unique long 47 (UL47) gene were determined by the 50% tissue culture infectious dose (TCID50) and real-time polymerase chain reaction methods, respectively.

The bacterial supernatant in dilutions of 1:4 and 1:8, selenium in concentrations of 0.5 and 1 μM, and a combination of them had a cytotoxicity level lower than 80% in HeLa cells. The HSV-1 titers in pre-infection and post-infection assays with a dilution of 1:4 supernatant decreased by about 2.16 and 1 log10 TCID50/mL, respectively. Moreover, 1 μM Se could reduce the virus titer by 2.33 log10 TCID50/mL. The virus titer showed a greater decrease when Se and the bacterial supernatants were combined than when only one of the two was used. The highest selectivity index (SI) was obtained when selenium and bacterial supernatant were combined (SI = 29.2). The combined use of 1 μM Se and a 1:4 dilution of B. clausii supernatant caused the greatest drop in virus titer (3.3 log10 TCID50/mL) in comparison to other treatment conditions. The UL47 gene expression was reduced by Se at concentrations of 0.5 and 1 μM by about 1.6- and 2-fold, respectively. The UL47 expression showed a higher decline when selenium and bacterial supernatant were combined than when only one of the two was employed, which is similar to viral titer data.

Selenium and the supernatant of B. clausii have potent antiviral activity against HSV-1. The combination of selenium and the bacterial supernatant has a synergistic effect in reducing HSV-1 replication. However, further research is required to fully understand how they inhibit viruses.

Despite several challenges, the SARS-CoV-2 pandemic is still not over. Rapid mass-scale immunization is critical to prevent further COVID-19-associated deaths.

Herein, we aimed to evaluate the rapid ramp-up effects of spike antibodies in response to Sputnik V, Sinopharm, and SinoVac first dose administration in the general public of Pakistan.

A cross-sectional study was conducted on 2000 participants to examine Sputnik V, Sinopharm, and SinoVac first dose effects 21 days post-administration. From 1200 real-time PCR negative subjects, the samples were subjected to SARS-CoV-2 spike antibody levels using electro-chemiluminescence immunoassay (ECLIA) (Elecsys, # 09289267190 Roche, USA).

SARS-CoV-2 spike protein positivity was detected highest at 87% among participants receiving SputnikV with SARS-CoV-2 spike protein antibodies > 1.5 AU/mL compared to 47.6% and 25% in individuals receiving Sinopharm and SinoVac, respectively. Also, 36.04% of the Sputnik-administered individuals depicted antibody levels > 250 AU/mL. Of the participants, 55% had a previous history of COVID-19. Also, 14.86%, 4.76%, and 0% of the SputnikV, Sinopharm, and SinoVac administered subjects showed antibodies > 100 AU/mL, respectively, while > 25 AU/mL antibodies were found in 10.70% of SputnikV, 19.04% of Sinopharm and 10.71% of SinoVac administered individuals. Moreover, > 1.5 - 2.5 AU/mL antibodies levels were found in 25.10%, 23.80%, and 14.28% of participants with SputnikV, Sinopharm, and SinoVac administered vaccines, respectively. The antibody titers of < 1.5 AU/mL were detected among 13.30%, 52.38%, and 46.42% of subjects administered with SputnikV, Sinopharm, and SinoVac vaccines, respectively.

Even before administrating the second booster dose of SputnikV, a significantly higher number of patients depicted rapid ramp-up of SARS-CoV-2 specific spike antibodies, which can significantly contribute to rapid mass-immunization. Despite all challenges, persistent antibody plateau monitoring is critical to attaining humoral immunity against SARS-CoV-2 infections.

Salmonella is an important foodborne pathogen that causes diarrhea in humans worldwide.

This study aimed to determine the serotype distribution, antibiotic-resistant genes, and Salmonella pathogenicity island (SPI) genes of clinical isolates of Salmonella in Weifang.

A total of 111 Salmonella strains were collected from Weifang People’s Hospital between 2018 and 2020 and subjected to serotyping using the Kauffmann-White antigen table. Meanwhile, the polymerase chain reaction detected eleven SPI1-6 genes and six antibiotic resistance genes.

Among the 111 Salmonella strains, 17 serotypes were identified, with S. Typhimurium, S. Typhi, and S. Enteritidis being the most prevalent. The hilA, ssaB, sseC, marT, siiE, pipB, sopB, and pagN SPI1-6 genes were all found during analysis. The InvA, misL, and siiD genes were detected at 98.2, 97.30, and 97.30% rates, respectively. Also, sul2 and blaTEM were the most prevalent antibiotic resistance genes in this investigation, accounting for 68.47 and 21.62% of the total, respectively.

Salmonella isolated from the clinical samples was found to have a diversity of serotypes and possessed various SPI and antibiotic resistance genes.

The rise of antibiotic-resistant Mycobacterium tuberculosis strains has accelerated the hunt for novel drugs for tuberculosis (TB).

This study identified a novel compound with strong anti-TB efficacy against several resistant M. tuberculosis strains from a chemical library of naphthoquinone derivatives.

The identified chemical was designated as MDN-6 (methyl-1,4-bis(2-(diethylamino)ethoxy)-2-naphthoate).

It significantly inhibited all the tested Mycobacterium strains, including 24 clinically isolated resistant strains. The minimum inhibitory concentrations of MDN-6 were between 0.02 and 25 g/mL. It also had partially synergistic activity against extensively drug-resistant M. tuberculosis when coupled with rifampicin and streptomycin. Additionally, MDN-6 demonstrated a superior post-antibiotic effect over isoniazid and exhibited comparable inhibitory efficacy against Mycobacterium marinum and Mycobacterium kansasii. Besides the antimicrobial effect, MDN-6 had a 50% lethal dosage (LD50) of 279.1 mg/kg in female BALB/c mice.

MDN-6 is a promising anti-TB therapeutic candidate against drug-resistant M. tuberculosis. However, further investigation is necessary to elucidate the action mechanism and assess the drug’s in vivo therapeutic potential.

Limited medications are available for post-exposure prophylaxis of coronavirus disease 2019 (COVID-19) infection. Whether bromhexine can prevent or mitigate symptomatic infection after virus exposure is undetermined.

We aimed to evaluate bromhexine's effect on preventing COVID-19 after close contact exposure.

A multi-center randomized, double-blind, placebo-controlled clinical trial was conducted on 372 adults (≥ 18 years) who had close contact within four days with a household member with confirmed COVID-19. They were randomly assigned to receive bromhexine 8 mg (n = 187) or placebo (n = 185) three times a day for two weeks. The primary outcome was the incidence of symptomatic COVID-19. Secondary outcomes included hospitalization or death, confirmed COVID-19 by Polymerase Chain Reaction (PCR) in symptomatic patients, and adverse drug reactions.

The incidence of symptomatic COVID-19 was significantly lower in individuals who received bromhexine than in those who received the placebo (16 [8.6%] vs. 34 [18.4%], relative risk = 0.47, P = 0.005). PCR confirmation was reported in 13 (7.0%) and 26 (14.1%) individuals in the bromhexine and placebo groups, respectively (P = 0.025), with a relative risk reduction of 50%. The hospitalization rate, death, and medication side effects did not vary significantly between the bromhexine and placebo arms.

Bromhexine is an effective, non-invasive, affordable agent with a low side-effect profile to prevent symptomatic COVID-19. Early use of bromhexine potentially provides another layer of protection; hence, it can play a role in controlling the pandemic.