Human microbiome and prostate cancer development: current insights into the prevention and treatment / 医学前沿

The huge communities of microorganisms that symbiotically colonize humans are recognized as significant players in health and disease. The human microbiome may influence prostate cancer development. To date, several studies have focused on the effect of prostate infections as well as the composition of the human microbiome in relation to prostate cancer risk. Current studies suggest that the microbiota of men with prostate cancer significantly differs from that of healthy men, demonstrating that certain bacteria could be associated with cancer development as well as altered responses to treatment. In healthy individuals, the microbiome plays a crucial role in the maintenance of homeostasis of body metabolism. Dysbiosis may contribute to the emergence of health problems, including malignancy through affecting systemic immune responses and creating systemic inflammation, and changing serum hormone levels. In this review, we discuss recent data about how the microbes colonizing different parts of the human body including urinary tract, gastrointestinal tract, oral cavity, and skin might affect the risk of developing prostate cancer. Furthermore, we discuss strategies to target the microbiome for risk assessment, prevention, and treatment of prostate cancer.

A possible protective role for Bacillus Calmette-Guérin therapy in urinary bladder cancer in the era of COVID-19: a brief report

Given the systemic immunogenic effects of Bacillus Calmette-Guérin (BCG) therapy in patients with bladder cancer and its non-specific immunogenic effects in viral respiratory diseases, we aimed to study severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in bladder cancer patients with a history of BCG therapy. In the present study, all bladder cancer survivors with a history of BCG therapy were identified and included in the study according to the data recovered from the UORC (Uro-Oncology Research Center) registry database. These patients were followed up in terms of acquiring coronavirus disease 2019 (COVID-19). Among the studied patients, 102 eligible bladder cancer patients with a history of BCG therapy entered the study. The males constituted the majority of the patients (86.3%), and more than half of the study population (55.9%) were above 65 years old. Among the understudy patients, 12.7% were confirmed for COVID-19. The study results did not show a statistically significant association between the time and number of BCG therapy courses and SARS-CoV-2 infection. Although no statistically significant association was observed between receiving BCG therapy and developing COVID-19, the infection rate in patients who had recently received BCG therapy was lower than those who had received therapy more than a year ago.

Autolysin (lytA) recombinant protein: a potential target for developing vaccines against pneumococcal infections

Purpose@#N-acetylmuramoyl-l-alanine amidase known as lytA, is an immunogenic protein that plays an important role in the pathogenesis of Streptococcus pneumoniae. It is highly conserved among S. pneumoniae strains and is absent among other Streptococcus species. In the present study, the level of antibodies against the lytA recombinant protein was evaluated in healthy individuals’ sera. @*Materials and Methods@#DNA was extracted from S. pneumoniae ATCC 49619 to amplify lytA gene by polymerase chain reaction assay. The lytA amplicon and pET28a vector were separately double digested using Nde-1 and Xho1 restriction enzymes and then ligated together with ligase enzyme. The recombinant plasmid was expressed in Escherichia coli BL21 strain and the lytA recombinant protein purified using nickel-nitrilotriacetic acid affinity chromatography. Western blot was carried to detect lytA recombinant protein. Sixty healthy individual’s sera (at three age groups: group 1, <2; group 2, 2–40; and group 3, 60–90 years old) were collected and the titers of anti-lytA antibodies were determined. @*Results@#The lytA gene was highly expressed in E. coli BL21 host. The recombinant lytA protein was purified and confirmed by western blotting. Tukey test analysis showed that there were no significant differences among the age groups considering the anti-lytA titer of 10. However, at the anti-lytA titer of 60, significant differences were observed between group 1 vs. group 2 (p<0.001); group 1 vs. group 3 (p=0.003), and group 2 vs. group 3 (p=0.024). @*Conclusion@#The lytA protein seems to be a highly immunogenic antigen and a potential target for developing vaccines against pneumococcal infections.

Autolysin (lytA) recombinant protein: a potential target for developing vaccines against pneumococcal infections

Purpose@#N-acetylmuramoyl-l-alanine amidase known as lytA, is an immunogenic protein that plays an important role in the pathogenesis of Streptococcus pneumoniae. It is highly conserved among S. pneumoniae strains and is absent among other Streptococcus species. In the present study, the level of antibodies against the lytA recombinant protein was evaluated in healthy individuals’ sera. @*Materials and Methods@#DNA was extracted from S. pneumoniae ATCC 49619 to amplify lytA gene by polymerase chain reaction assay. The lytA amplicon and pET28a vector were separately double digested using Nde-1 and Xho1 restriction enzymes and then ligated together with ligase enzyme. The recombinant plasmid was expressed in Escherichia coli BL21 strain and the lytA recombinant protein purified using nickel-nitrilotriacetic acid affinity chromatography. Western blot was carried to detect lytA recombinant protein. Sixty healthy individual’s sera (at three age groups: group 1, <2; group 2, 2–40; and group 3, 60–90 years old) were collected and the titers of anti-lytA antibodies were determined. @*Results@#The lytA gene was highly expressed in E. coli BL21 host. The recombinant lytA protein was purified and confirmed by western blotting. Tukey test analysis showed that there were no significant differences among the age groups considering the anti-lytA titer of 10. However, at the anti-lytA titer of 60, significant differences were observed between group 1 vs. group 2 (p<0.001); group 1 vs. group 3 (p=0.003), and group 2 vs. group 3 (p=0.024). @*Conclusion@#The lytA protein seems to be a highly immunogenic antigen and a potential target for developing vaccines against pneumococcal infections.

Prevalence of methicillin-resistant staphylococcus aureus carrying panton- valentine leukocidin gene in cutaneous infections in the city of Isfahan

Methicillin-Resistant Staphylococcus aureus [MRSA] is a major cause of Nosocomial and community infections that are becoming increasingly difficult to combat, because of emerging resistance to all classes of antibiotics. Moreover Panton-Valentine leukocidin [PVL] is an important virulence factor in S. aureus and causes white blood cell destruction, necrosis and accelerated apoptosis. The aim of this study was to determine the frequency of PVL-positive MRSA in cutaneous infections, for epidemiological purposes and also to determine antibiotic resistance of the isolates. Collectively, 56 isolates of S. aureus were obtained from Isfahan University of Medical sciences affiliated hospitals and confirmed with biochemical tests [coagulase, mannitol fermentation, and DNase]. Then polymerase chain reaction [PCR] was used to detect pvl gene. Coagulase gene was used as internal control. The antibiotic susceptibility of all isolates to methicillin was determined using disk diffusion method. Out of 56 isolates 14.3% were PVL positive that 37.5% were from abscess and 62.5% were from wound. Among all of these isolates 67.8% were MRSA and also 75% of PVL-positive isolates were MRSA. The prevalence of PVL positive MRSA in cutaneous isolates is high. Future works are necessary for a more complete understanding of distribution of these virulent isolates in nasal carriers to decrease the risk of infections.