In Vitro Antimicrobial Activity and Aggregation Abilities of Probiotic Lactobacillus casei and Lactobacillus salivarius Against Oral Pathogens

ABSTRACT@#The antagonistic effect of probiotics against oral pathogens merits exploration because these bacteria are beneficial to the host’s health. The antimicrobial activity of two probiotic strains, Lactobacillus casei and Lactobacillus salivarius, as well as L. casei and L. salivarius combination (1:1), was investigated against Streptococcus mutans, Streptococcus sobrinus, Candida albicans, Candida glabrata and Candida tropicalis using agar-well diffusion, auto-aggregation and coaggregation assays. L. salivarius cell-free supernatant (CFS) alone exhibited greater inhibitory effect against Streptococci spp. compared to L. casei CFS alone and the combination. However, no inhibition was observed for Candida spp. L. salivarius alone exhibited significantly stronger auto-aggregation than L. casei alone (p ≤ 0.05) and L. casei and L. salivarius combination. L. salivarius exhibited strong coaggregation ability with Candida spp., followed by Streptococci spp. while L. casei exhibited coaggregation only with Streptococci spp. However, L. casei and L. salivarius combination did not display any coaggregation with all strains. L. salivarius alone exhibited a stronger antagonistic effect on the tested organisms than L. casei alone or in combination. Based on the results, both probiotic strains showed good antimicrobial activities against oral pathogens and should be further studied for their human health benefits.

Serological and Molecular Detection of Toxoplasmosis among Blood Donors in Tertiary Hospital of Malaysia

@#Introduction: This preliminary cross-sectional study aimed to investigate the prevalence of toxoplasmosis among blood donors in Kelantan, Malaysia. Methods: A total of 56 blood donors were screened by an enzyme-linked immunosorbent assay (ELISA) for anti-T. gondii Immunoglobulin G (IgG) and Immunoglobulin M (IgM) antibodies. Positive T. gondii IgG and IgM were further tested for IgG avidity ELISA. All extracted deoxyribonucleic acids (DNAs) from whole blood samples were analyzed for the presence of the Toxoplasma B1 gene and the ITS1 region by polymerase chain reaction (PCR). The socio-demographic data of donors was assessed using a data collection form. Results: Out of 56 blood donors, 24 (42.86%) donors were IgG+/IgM-, and 2 (3.57%) donors were IgG+/IgM+ with one of them having a high avidity index indicating as past infection for more than 20 weeks and the other with a low avidity index indicating as recent infection within 20 weeks. None of the samples tested positive for the presence of the Toxoplasma B1 gene and the ITS1 region. A univariate analysis showed that only employment status was significantly associated with Toxoplasma seropositivity. Conclusion: The seroprevalence of toxoplasmosis among blood donors in Kelantan, Malaysia, was 46.43%. Nevertheless, direct detection by PCR showed that this parasite was absent in the blood. These results highlight that the blood donors in this study had previously been exposed to T. gondii infection. The parasite may still remain in certain tissues but does not freely circulate in the blood.

Detection of human papillomavirus in oropharyngeal squamous cell carcinoma / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Worldwide there has been a significant increase in the incidence of oropharyngeal squamous cell carcinoma (OPSCC) etiologically attributed to oncogenic human papillomavirus (HPV). Reliable and accurate identification and detection tools are important as the incidence of HPV-related cancer is on the rise. Several HPV detection methods for OPSCC have been developed and each has its own advantages and disadvantages in regard to sensitivity, specificity, and technical difficulty. This review summarizes our current knowledge of molecular methods for detecting HPV in OPSCC, including HPV DNA/RNA polymerase chain reaction (PCR), loop-mediated isothermal amplification (LAMP), p16 immunohistochemistry (IHC), and DNA/RNA in situ hybridization (ISH) assays. This summary may facilitate the selection of a suitable method for detecting HPV infection, and therefore may help in the early diagnosis of HPV-related carcinoma to reduce its mortality, incidence, and morbidity.

High frequency of Haemophilus influenzae associated with respiratory tract infections among Malaysian Hajj pilgrims.

BACKGROUND: Overcrowding during the annual Hajj pilgrimage has been known to increase the risk of infectious diseases transmission. Despite the high prevalence of respiratory illness among Malaysian Hajj pilgrims, knowledge about the etiologic pathogens is yet very limited. Thus, this study aimed to determine the spectrum of bacterial respiratory pathogens among the Hajj pilgrims returning to Malaysia in year 2016. METHODS: Expectorated sputum specimens were collected from the Hajj pilgrims with symptomatic respiratory tract infections (RTIs). Subsequently, the bacterial pathogens were identified using the standard bacteriological culture method and Vitek II system. RESULTS: This study indicated that 255 (87.33%) out of 292 cultured sputa were positive with at least one potential pathogenic bacteria. Out of 345 total bacterial isolates, 60% (n=207) were Haemophilus influenzae, which was associated with both single bacterium infection (132/173, 76.3%) and multiple bacterial infections (75/82, 91.5%). The other bacterial isolates included; Klebsiella pneumoniae (n=37, 10.7%), Moraxella catarrhalis (n=27, 7.8%), Haemophilus parainfluenzae (n=25, 7.2%), Streptococcus group G (n=18, 5.2%), Klebsiella spesies (n=16, 4.6%), Streptococcus pneumoniae (n=11, 3.2%) and few other organisms. CONCLUSION: High frequency of H. influenzae was isolated from Malaysian Hajj pilgrims, especially those with respiratory symptoms. Further study should evaluate the actual pathogenicity of the organism and the interactions between the respiratory microbiota towards developing effective prevention strategies of RTIs among the local pilgrims.

In-vitro antimicrobial effectiveness of herbal-based mouthrinses against oral microorganisms

OBJECTIVE: To evaluate the in vitro antimicrobial effectiveness of commercial herbal-based mouthrinses against oral microorganisms. METHODS: A total of three mouthrinses (OX, Pesona and Watsons) were tested for their antimicrobial activity against six oral organisms, Streptococcus mutans (S. mutans), Streptococcus sobrinus (S. sobrinus), Lactobacillus salivarius (L. salivarius), Staphylococcus aureus (S. aureus), Pseudomonas aeruginosa (P. aeruginosa) and Candida albicans (C. albicans) by standard agar-disk diffusion assay. Oradex mouthrinse containing 0.12% chlorhexidine gluconate and sterile distilled water was served as positive and negative controls, respectively. RESULTS: All mouthrinse formulations were effective in inhibiting the growth of S. mutans, S. sobrinus, L. salivarius and C. albicans. Among the tested mouthrinses, Pesona was the only effective mouthrinse against S. aureus and P. aeruginosa, similar to Oradex mouthrinse. Pesona mouthrinse formulation appears to be as effective as Oradex mouthrinse formulation to kill S. aureus and P. aeruginosa. Statistical analysis showed no significant difference among the tested formulations regarding their antimicrobial activities (P > 0.05). CONCLUSIONS: Pesona was not the only herbal mouthrinse effective in inhibiting the growth of S. mutans, S. sobrinus, L. salivarius and C. albicans in vitro. All tested formulations were effective against those strains. Our findings may serve as a guide for selecting a kind of herbal mouthrinses as well as providing information to the dental professionals about the efficacy of these products.