The acid tolerance response and pH adaptation of Enterococcus faecalis in extract of lime Citrus aurantiifolia from Aceh Indonesia

Study on intestinal parasitic infections and gut microbiota in cancer patients at a tertiary teaching hospital in Malaysia

Intestinal parasitic infections (IPIs) can lead to significant morbidity and mortality in cancer patients. While they are unlikely to cause severe disease and are self-limiting in healthy individuals, cancer patients are especially susceptible to opportunistic parasitic infections. The gut microbiota plays a crucial role in various aspects of health, including immune regulation and metabolic processes. Parasites occupy the same environment as bacteria in the gut. Recent research suggests intestinal parasites can disrupt the normal balance of the gut microbiota. However, there is limited understanding of this co-infection dynamic among cancer patients in Malaysia. A study was conducted to determine the prevalence and relationship between intestinal parasites and gut microbiota composition in cancer patients. Stool samples from 134 cancer patients undergoing active treatment or newly diagnosed were collected and examined for the presence of intestinal parasites and gut microbiota composition. The study also involved 17 healthy individuals for comparison and control. Sequencing with 16S RNA at the V3-V4 region was used to determine the gut microbial composition between infected and non-infected cancer patients and healthy control subjects. The overall prevalence of IPIs among cancer patients was found to be 32.8%. Microsporidia spp. Accounted for the highest percentage at 20.1%, followed by Entamoeba spp. (3.7%), Cryptosporidium spp. (3.0%), Cyclospora spp. (2.2%), and Ascaris lumbricoides (0.8%). None of the health control subjects tested positive for intestinal parasites. The sequencing data analysis revealed that the gut microbiota diversity and composition were significantly different in cancer patients than in healthy controls (p < 0.001). A significant dissimilarity was observed in the bacterial composition between parasite-infected and non-infected patients based on Bray-Curtis (p = 0.041) and Jaccard (p = 0.021) measurements. Bacteria from the genus Enterococcus were enriched in the parasite-infected groups, while Faecalibacterium prausnitzii reduced compared to non-infected and control groups. Further analysis between different IPIs and non-infected individuals demonstrated a noteworthy variation in Entamoeba-infected (unweighted UniFrac: p = 0.008), Cryptosporidium-infected (Bray-Curtis: p = 0.034) and microsporidia-infected (unweighted: p = 0.026; weighted: p = 0.019; Jaccard: p = 0.031) samples. No significant dissimilarity was observed between Cyclospora-infected groups and non-infected groups. Specifically, patients infected with Cryptosporidium and Entamoeba showed increased obligate anaerobic bacteria. Clostridiales were enriched with Entamoeba infections, whereas those from Coriobacteriales decreased. Bacteroidales and Clostridium were found in higher abundance in the gut microbiota with Cryptosporidium infection, while Bacillales decreased. Additionally, bacteria from the genus Enterococcus were enriched in microsporidia-infected patients. In contrast, bacteria from the Clostridiales order, Faecalibacterium, Parabacteroides, Collinsella, Ruminococcus, and Sporosarcina decreased compared to the non-infected groups. These findings underscore the importance of understanding and managing the interactions between intestinal parasites and gut microbiota for improved outcomes in cancer patients.

Bacterial biota composition in gut regions of black soldier fly larvae reared on industrial residual streams: revealing community dynamics along its intestinal tract

Some insect species have gained attention as efficient bioconverters of low-value organic substrates (i.e., residual streams) into high-value biomass. Black soldier fly (BSF) (Hermetia illucens) larvae are particularly interesting for bioconversion due to their ability to grow on a wide range of substrates, including low-value industrial residual streams. This is in part due to the plasticity of the gut microbiota of polyphagous insects, like BSF. Gut microbiota composition varies depending on rearing substrates, via a mechanism that might support the recruitment of microorganisms that facilitate digestion of a specific substrate. At the same time, specific microbial genera do persist on different substrates via unknown mechanisms. This study aimed to offer insights on this microbial plasticity by investigating how the composition of the bacterial community present in the gut of BSF larvae responds to two industrial residual streams: swill (a mixture of catering and supermarket leftovers) and distiller's dried grains with solubles. The bacterial biota composition of substrates, whole larvae at the beginning of the rearing period and at harvest, rearing residues, and larval gut regions were investigated through 16S rRNA gene sequencing. It was observed that both substrate and insect development influenced the bacterial composition of the whole larvae. Zooming in on the gut regions, there was a clear shift in community composition from a higher to a lower diversity between the anterior/middle midgut and the posterior midgut/hindgut, indicating a selective pressure occurring in the middle midgut region. Additionally, the abundance of the bacterial biota was always high in the hindgut, while its diversity was relatively low. Even more, the bacterial community in the hindgut was found to be relatively more conserved over the different substrates, harboring members of the BSF core microbiota. We postulate a potential role of the hindgut as a reservoir for insect-associated microbes. This warrants further research on that underexplored region of the intestinal tract. Overall, these findings contribute to our understanding of the bacterial biota structure and dynamics along the intestinal tract, which can aid microbiome engineering efforts to enhance larval performance on (industrial) residual streams.

Compositional Quality and Possible Gastrointestinal Performance of Marketed Probiotic Supplements

The local pharmacies and shops are brimming with various probiotic products that herald a range of health benefits. The poor quality of probiotic products in both dosage and species is symptomatic of this multi-billion-dollar market making it difficult for consumers to single out reliable ones. This study aims to fill the potential gap in the labeling accuracy of probiotic products intended for human consumption. We describe a combinatorial approach using classical culture-dependent technique to quantify and molecular techniques (16 s rRNA gene sequencing, multilocus sequence, and ribotyping) for strain recognition of the microbial contents. The full gamut of probiotic characteristics including acid, bile and lysozyme tolerances, adhesiveness, anti-pathogenicity, and degree of safeness were performed. Their capacity to endure gastro-intestinal (GIT) stresses and select drugs was assessed in vitro. Our results forced us to declare that the local probiotic market is essentially unregulated. Almost none of the probiotic products tested met the label claim. Some (11%) have no viable cells, and a quarter (27%) showing significant inter-batch variation. A lower microbial count was typical with undesirables constituting a quarter of the total (~ 27%). Half of the products contained antibiotic-resistant strains; the unregulated use of these probiotics carries the risk of spreading antibiotic resistance to gut pathobionts. Poor tolerance to gut conditions and mediocre functionalism make the case worse. The current regulatory systems do not take this discrepancy into account. We recommend an evidence-based regular market surveillance of marketed probiotics to ensure the authenticity of the claims and product effectiveness.

Phosphorus Recovery from Sewage Sludge Using Acidithiobacilli

Sewage sludge contains a significant amount of phosphorus (P), which could be recycled to address the global demand for this non-renewable, important plant nutrient. The P in sludge can be solubilized and recovered so that it can be recycled when needed. This study investigated the P solubilization from sewage sludge using Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans. The experiment was conducted by mixing 10 mL of sewage sludge with 90 mL of different water/liquid medium/inoculum and incubated at 30 °C. The experiment was conducted in three semi-continuous phases by replacing 10% of the mixed incubated medium with fresh sewage sludge. In addition, 10 g/L elemental sulfur (S) was supplemented into the medium in the third phase. The pH of the A. thiooxidans and A. ferrooxidans treated sludge solutions was between 2.2 and 6.3 until day 42. In phase 3, after supplementing with S, the pH of A. thiooxidans treated sludge was reduced to 0.9, which solubilized and extracted 92% of P. We found that acidithiobacilli supplemented with S can be used to treat sludge, i.e., achieve hygienization, removal of heavy metals, and solubilization and recovery of P.

Experimental infection of Enterococcus faecalis in red tilapia (Oreochromis hybrid) revealed low pathogenicity to cause streptococcosis

Background:

Streptococcosis, as a bacterial disease with broad tropism in fish and one of the causes of septicemia. Enterococcus faecalis is one of the causative agents of streptococcosis that can be isolated in tilapia.

Aim:

This study was undertaken to complete the reporting gap on the pathogenicity profile and clinical symptoms of E. faecalis bacterial infection in red tilapia (Oreochromis hybrid). The study is expected to provide enriching information regarding recognizable clinical signs in the field that can lead to the diagnosis of streptococcosis caused by E. faecalis, especially in the Indonesian aquaculture environment.

Methods:

The method used in this artificial infection study using red tilapia, which were divided into two types of route groups infection, namely intraperitoneal (IP) and peroral (PO) with bacterial concentrations given for each route of infection to be 2.1 × 10⁸ CFU ml⁻¹; 2.1 × 10⁷ CFU ml⁻¹; and 2.1 × 10⁶ CFU ml⁻¹. One group was given brain heart infusion broth media sterile as a non-infectious control. Clinical symptoms, changes in swimming habits and consuming feed, external and internal organ lesion, and leukocytes profile changes were observed during the observation period along 14 days to evaluate the infectious effect of each treated fish group. The lethal dose 50 (LD⁵⁰) was estimated with the Spearman–Kärber method. The evaluation of the leukocyte profile was performed to find leukocytosis as the clinical sign of infection.

Results:

The results showed variations in clinical symptoms inflicted on fish through death or the moribund stage. The highest mortality occurred in the treatment group of 2.1 × 10⁸ CFU ml⁻¹ with the PO route. The bacterial concentration of 2.1 × 10⁷ CFU ml⁻¹ given either as PO or IP can cause mild infection symptoms but did not cause mortality. The LD₅₀ of the PO and IP route was obtained at 1.99 × 10⁸ CFU ml⁻¹ and 0.79 × 10⁸ CFU ml⁻¹, respectively. The total leukocytes in the infected fish group increased significantly (p < 0.05) by twofold when compared with the non-infectious group. The bacteria’s discovery on the blood smear examination was taken from fresh dead fish or moribund fish in the treatment group of 2.1 × 10⁸ CFU ml⁻¹, for both PO and IP.

Conclusion:

Enterococcus faecalis with low pathogenicity can lead to septicemia, characterized by a total increase in leukocytes, bacteria’s discovery on the blood smear examination, and various clinical symptoms systemically found in the treated fish.

Antimicrobial Efficacy of Fruit Peels Eco-Enzyme against Enterococcus Faecalis: An In Vitro Study

Sodium hypochlorite (NaOCl), an effective endodontic irrigant against Enterococcus faecalis (EF), is harmful to periapical tissues. Natural pineapple-orange eco-enzymes (M-EE) and papaya eco-enzyme (P-EE) could be potential alternatives. This study aimed to assess the antimicrobial efficacy of M-EE and P-EE at different concentrations and fermentation periods against EF, compared to 2.5% NaOCl. Fermented M-EE and P-EE (3 and 6 months) at various concentrations were mixed with EF in a 96-well plate incubated for 24 h anaerobically. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of M-EE and P-EE were determined via EF growth observation. EF inhibition was quantitatively measured and compared between different irrigants using the one-way analysis of variance (ANOVA), and different fermentation periods using the independent-samples T-test. M-EE and P-EE showed MIC at 50% and MBC at 100% concentrations. There was no significant difference in antimicrobial effect when comparing M-EE and P-EE at 50% and 100% to 2.5% NaOCl. P-EE at 6 months fermentation exhibited higher EF inhibition compared to 3 months at concentrations of 25% (p = 0.017) and 0.78% (p = 0.009). The antimicrobial properties of M-EE and P-EE, at both 100% and 50% concentrations, are comparable to 2.5% NaOCl. They could therefore be potential alternative endodontic irrigants, but further studies are required.