Genera Of Bacteria Research Articles

Prevalence and Antibiotic Resistance Pattern of Streptococcus, Staphylococcus, Neisseria meningitidis and Enterobacteriaceae in Two Reference Hospitals of Yaoundé: An Overview before and during COVID-19 Pandemic Era.

The COVID-19 pandemic led to tremendously use of antimicrobial due to the lack of proper treatment strategies, raising concerns about emergence of antimicrobial resistance (AMR). This study aimed at determining the prevalence and antibiotic resistance pattern of selected bacteria isolates in 02 referral health facilities in Yaoundé before and during the COVID-19 pandemic era. We conducted a retrospective study over a period of 03 years (from 1 January 2019 to 31 December 2021) in the bacteriology units of the Central and General Hospitals of Yaoundé, Cameroon. Data on bacteria genera (Streptococcus, Staphylococcus, Neisseria meningitidis and Enterobacteriaceae) as well as their corresponding specifics antibiotics: Cefixime, azythromycin and erythromycin were obtained from laboratory records. The global resistance rate of bacteria as well as their correlation with antibiotics according to COVID-19 pandemic era was determined and compared. For p < 0.05, the difference was statistically significant. In all, 426 bacterial strains were included. It appeared that the highest number of bacteria isolates and lowest rate of bacterial resistance were recorded during the pre-COVID-19 period in 2019 (160 isolates vs. 58.8% resistance rate). Conversely, lower bacteria strains but greater resistance burden were recorded during the pandemic era (2020 and 2021) with the lowest bacteria amount and peak of bacteria resistance registered in 2020, the year of COVID-19 onset (120 isolates vs. 70% resistance in 2020 and 146 isolates vs. 58.9% resistance in 2021). In contrast to almost all others groups of bacteria where the resistance burden was quite constant or decreasing over years, the Enterobacteriaceae exhibited greater resistance rate during the pandemic period [60% (48/80) in 2019 to 86.9% (60/69) in 2020 and 64.5% (61/95) in 2021)]. Concerning antibiotics, unlike erythromycin, azythromycin related resitance increased during the pandemic period and the resistance to Cefixim tends to decrease the year of the pandemic onset (2020) and re-increase one year therafter. A significant association was found between resistant Enterobacteriaceae strains and cefixime (R = 0.7; p = 0.0001) and also, between resistant Staphylococcus strains and erythromycin (R = 0.8; p = 0.0001). These retrospective data showed a herogeneous MDR bacteria rate and antibiotic resistance pattern over time before and during the COVID-19 pandemic era suggesting that antimicrobial resistance needs to be more closely monitored.

Production of antibacterial compounds using Bacillus spp. isolated from thermal springs in Saudi Arabia

Seventeen water samples were collected from four different thermal springs in Saudi Arabia. Microbiological assays were used to assess the antibacterial activities of bacterial colonies against antibiotic-resistant and susceptible-bacterial strains, and 16S rRNA gene sequencing was used to identify the genus and species of these antibiotic-producing bacteria. Chromatography and spectroscopy were used to separate the active compounds and help figuring out what their structures were. Four compounds were isolated using bacteria: N-acetyltryptamine (1), isovaleric acid (2), ethyl-4-ethoxybenzoate (3) and phenylacetic acid (4). Compounds 1, 2 and 4 were produced from Bacillus pumilus and 3 was from Bacillus licheniformis (AH-E1). The outcomes of the minimum inhibitory concentrations (MICs) showed that all pure compounds produced in this work had antibacterial activities against Gram-positive pathogens (between 128 mg/L and 512 mg/L compared to the control) and compound 2 had activity against E. coli.

Identification and Biosynthetic Study of the Siderophore Lysochelin in the Biocontrol Agent Lysobacter enzymogenes.

Lysobacter is a genus of bacteria emerging as new biocontrol agents in agriculture. Although iron acquisition is essential for the bacteria, no siderophore has been identified from any Lysobacter. Here, we report the identification of the first siderophore, N1,N8-bis(2,3-dihydroxybenzoyl)spermidine (lysochelin), and its biosynthetic gene cluster from Lysobacter enzymogenes. Intriguingly, the deletion of the spermidine biosynthetic gene encoding arginine decarboxylase or SAM decarboxylase eliminated lysochelin and the antifungals, HSAF and its analogues, which are key to the disease control activity and to the survival of Lysobacter under oxidative stresses caused by excess iron. The production of lysochelin and the antifungals is greatly affected by iron concentration. Together, the results revealed a previously unrecognized system, in which L. enzymogenes produces a group of small molecules, lysochelin, spermidine, and HSAF and its analogues, that are affected by iron concentration and critical to the growth and survival of the biocontrol agent.

Evidence of phylosymbiosis in Formica ants.

Insects share intimate relationships with microbes that play important roles in their biology. Yet our understanding of how host-bound microbial communities assemble and perpetuate over evolutionary time is limited. Ants host a wide range of microbes with diverse functions and are an emerging model for studying the evolution of insect microbiomes. Here, we ask whether phylogenetically related ant species have formed distinct and stable microbiomes. To answer this question, we investigated the microbial communities associated with queens of 14 Formica species from five clades, using deep coverage 16S rRNA amplicon sequencing. We reveal that Formica species and clades harbor highly defined microbial communities that are dominated by four bacteria genera: Wolbachia, Lactobacillus, Liliensternia, and Spiroplasma. Our analysis reveals that the composition of Formica microbiomes mirrors the phylogeny of the host, i.e., phylosymbiosis, in that related hosts harbor more similar microbial communities. In addition, we find there are significant correlations between microbe co-occurrences. Our results demonstrate Formica ants carry microbial communities that recapitulate the phylogeny of their hosts. Our data suggests that the co-occurrence of different bacteria genera may at least in part be due to synergistic and antagonistic interactions between microbes. Additional factors potentially contributing to the phylosymbiotic signal are discussed, including host phylogenetic relatedness, host-microbe genetic compatibility, modes of transmission, and similarities in host ecologies (e.g., diets). Overall, our results support the growing body of evidence that microbial community composition closely depends on the phylogeny of their hosts, despite bacteria having diverse modes of transmission and localization within the host.

Pseudomonas aeruginosa Y12 play positive roles regulating larval gut communities when housefly encountered copper stress

Heavy metal contamination has become a global concern that threatens the lives of animals and insects throughout the food chain. Pseudomonas is a commonly found genus of bacteria that colonizes the intestines of insects and constitutes a necessary part of the insect gut microbiota. This research analyzed the influence of different concentrations of Cu2+ on housefly larval development, gut microbial structure and antioxidant defense system, and investigated the regulatory mechanism of P. aeruginosa Y12 on the gut microbiota when houseflies were exposed to Cu2+. We found that adding Cu2+ to the larval diet inhibited larval growth, while the mixed addition of P. aeruginosa Y12 and Cu2+ to the diet reduced the inhibitory effects of Cu2+ on larval growth. Oral administration of Cu2+ significantly changed the gut community structure and increased larval gut bacterial diversity. In vitro analysis revealed that P. aeruginosa Y12 showed Cu2+ adsorption effects and increased Cu2+ aggregation. The mixed addition of low concentrations of P. aeruginosa Y12 and Cu2+ to the larval diet caused a dynamic shift in the gut microbiota and resulted in a novel gut community structure with an increase in beneficial bacteria and a decrease in pathogenic bacteria. Furthermore, P. aeruginosa Y12 treatment influenced the activity of antioxidant enzymes in housefly larvae, indicating that the addition of P. aeruginosa Y12 to the larval diet could further influence the antioxidant system through P. aeruginosa Y12-Cu2+ interactions. In conclusion, our research revealed that intestinal flora dysbiosis was the essential reason why copper inhibits housefly larval growth. However, proper supplementation with P. aeruginosa Y12 played positive roles in regulating larval gut communities and protecting insects from toxic heavy metals.

Enterococcal Phages: Food and Health Applications.

Enterococcus is a diverse genus of Gram-positive bacteria belonging to the lactic acid bacteria (LAB) group. It is found in many environments, including the human gut and fermented foods. This microbial genus is at a crossroad between its beneficial effects and the concerns regarding its safety. It plays an important role in the production of fermented foods, and some strains have even been proposed as probiotics. However, they have been identified as responsible for the accumulation of toxic compounds-biogenic amines-in foods, and over the last 20 years, they have emerged as important hospital-acquired pathogens through the acquisition of antimicrobial resistance (AMR). In food, there is a need for targeted measures to prevent their growth without disturbing other LAB members that participate in the fermentation process. Furthermore, the increase in AMR has resulted in the need for the development of new therapeutic options to treat AMR enterococcal infections. Bacteriophages have re-emerged in recent years as a precision tool for the control of bacterial populations, including the treatment of AMR microorganism infections, being a promising weapon as new antimicrobials. In this review, we focus on the problems caused by Enterococcus faecium and Enterococcus faecalis in food and health and on the recent advances in the discovery and applications of enterococcus-infecting bacteriophages against these bacteria, with special attention paid to applications against AMR enterococci.

Population of Rhizosphere Bacteria on Several Species of Crops In The Tailings of Ex-Gold Mine

Tailings of ex-gold mines leave several environmental damage problems. Environmental damage causes disruption of microorganisms including bacteria. The revegetation of ex-gold mine tailings in Menjalin sub-district, Landak district, West Kalimantan has begun by local communities using agricultural crops. Women as farmers have an important role in the tailing revegetation process using agricultural crops. Therefore, women can help improve the tailings ecosystem as well as the family economy. The objective of the study was to detect the presence and density of bacterial populations in the rhizosphere of the revegetation crops. The research was conducted by survey method. Soil samples were taken compositely from the rhizosphere of four species of agricultural crops cultivated in tailings, i.e: Capsicum frutescens L., Solanum melongena, Ipomoea batatas L., and Manihot utilissima. The results showed that soil bacteria found growing well in the rhizospheres of four species crops. Two genera of bacteria were found in the tailing rhizosphere of ex-gold mine in Menjalin sub-district, namely Azotobacter and Pseudomonas. The bacterial population density in the rhizosphere of M. utilissima was significantly the highest. Meanwhile, the bacterial population density in the rhizosphere of C. frutescens, I. batatas, and S. melongena did not differ in the medium category. Further investigation found that the bacterial population in the rhizosphere of M. utilissima was 126.8 – 217 times denser than the other three crop species.

Association between the dynamics of the gut microbiota and responsiveness to mental health therapy

Abstract Growing evidence suggests that the intestinal microbiota may influence brain activity through metabolites and/or inflammation, but it is unclear whether the impact of psychological interventions such as meditation is connected to the dynamics of gut microbiota. In the presented study, we collected gut microbiota and plasma cytokine, chemokine, and growth factor data from a longitudinal cohort of 52 people (142 multi-omics samples) before, during, and after a nine-day meditation. We identified a strong relationship between the mental health status and the composition of gut microbiota. High level of bacteria genus Prevotellais correlated with improved meditation effects in stressed persons. In addition, a number of inflammatory cytokines, such as GROA, are significantly reduced in the Prevotella-dominating individuals. Following nine days of meditation, there is a decrease in pro-inflammatory cytokines, an increase in relative abundance of Prevotella, and an improvement in individual’s mental health measurements. Our study provides a novel link towards the possibility that the gut microbiota affects the level of stress through regulating cytokines.

Effects of forage type on the rumen microbiota, growth performance, carcass traits, and meat quality in fattening goats.

Forages fed to goats influence ruminal microbiota, and further contribute to affect growth performance, meat quality and its nutritional composition. Our objective for current study was to investigate the effects of different forages on growth performance, carcass traits, meat nutritional composition, rumen microflora, and the relationships between key bacteria and amino acids and fatty acids in the longissimus dorsi and semimembranosus muscles of goats. Boer crossbred goats were separately fed commercial concentrate diet supplemented with Hemarthria altissima (HA), Pennisetum sinese (PS), or forage maize (FG), and then slaughtered 90 days after the beginning of the experiment. Growth performances did not vary but carcass traits of dressing percentage, semi-eviscerated slaughter percentage, and eviscerated slaughter percentage displayed significant difference with the treatment studied. Meats from goats fed forage maize, especially semimembranosus muscles are rich in essential amino acids, as well as an increase in the amount of beneficial fatty acids. Our 16S rRNA gene sequencing results showed that the Firmicutes, Bacteroidetes, and Proteobacteria were the most dominant phyla in all groups but different in relative abundance. Further, the taxonomic analysis and linear discriminant analysis effect size (LEfSe) identified the specific taxa that were differentially represented among three forage treatments. The spearman's correlation analysis showed that rumen microbiota was significantly associated with the goat meat nutritional composition, and more significant positive correlations were identified in semimembranosus muscles when compared with longissimus dorsi muscles. More specifically, the lipid metabolism-related bacteria Rikenellaceae_RC9_gut_group showed positively correlated with meat amino acid profile, while genera Oscillospiraceae_UCG-005 were positively correlated with fatty acid composition. These bacteria genera might have the potential to improve nutritional value and meat quality. Collectively, our results showed that different forages alter the carcass traits, meat nutritional composition, and rumen microflora in fattening goats, and forage maize induced an improvement in its nutritional value.

Microbiological remediation of oil-contaminated soils

Microbiological remediation is a promising technology for the elimination of environmental contamination by oil and petroleum products, based on the use of the metabolic potential of microorganisms. The issue of environmental contamination by crude oil and its refined products is relevant in the Russian Federation since the oil industry is one of the leading sectors of the country. Mechanical and physico-chemical methods of treatment are widely used to clean oil-contaminated soils. However, the methods belonging to these groups have a number of significant drawbacks, which actualizes the development of new methods (mainly biological), since they are more environmentally friendly, cost-effective, less labor-intensive, and do not require the use of technical capacities. Various bio-based products based on strains and consortia of microorganisms have been developed that have proven effectiveness. They include certain genera of bacteria, microscopic fungi, and microalgae, substances or materials acting as sorbents of biological agents and designed to retain them in the soil and increase the efficiency of bioremediation, as well as some nutrients. Statistical data, the most effective methods, and technologies, as well as cases of using microorganisms to restore oil-contaminated soils in various climatic conditions are presented.

Bakteri Bacillus Sebagai Agen Kontrol Hayati dan Biostimulan Tanaman

One of the long-term constraints in agricultural productivity is the dependence of farmers on synthetic pesticides. The application of pesticides has a negative impact on ecosystems and human health. Utilization of microorganisms such as bacteria Bacillus as a biological control agent is an alternative to reduce the use of synthetic pesticides. A simpler discussion of the interaction between Bacillus and plants is important to carry out. This article aims to review the mechanism of the role of Bacillus as a biological control agent and growth stimulant in plants. Bacillus is a genus of bacteria that can be used as biological control agents because it is adaptive, capable of forming endospores and tolerant of various environmental conditions. These properties are advantageous in competition with phytopathogens through an antibiosis mechanism in the form of toxin production. Bacillus infection of plants is able to stimulate the emergence of systemic resistance as an initial defense mechanism in plants. Bacillus associated with plants can provide a growth stimulation effect because the metabolites produced are able to trigger the sensitivity of the root system for nutrient absorption and stimulate the regulation of growth regulators such as the synthesis of auxin, gibberellins, and cytokinins. Based on these reviews, the use of based biological agents and biostimulants Bacillus is expected to be able to support global efforts to achieve sustainable development targets, especially in the agricultural sector

Normal bacterial flora of the oral cavity in healthy pet rabbits (Oryctolagus cuniculus).

Rabbits often suffer from dental disease, including dental abscesses and periodontal/apical infections. With odontogenic infection and abscessation, a bacterial aetiology can be proven by bacterial culture and identification. Although studies exist on the bacterial flora of dental abscesses, the information available to date on the bacterial flora of the oral cavity in healthy rabbits is limited. This study aims to evaluate the cultivable bacterial flora in the oral cavity of healthy, young, pet rabbits and to compare this flora with the pathologic flora of odontogenic abscesses described in the literature. Samples were collected from the oral cavity of 33 healthy, young pet rabbits undergoing routine procedures. Oral cavity culture specimens were collected by rolling a sterile flocked paediatric swab in the mouth. Identification was first attempted by morphological assessment, Gram staining and mass spectrometry (MALDI-TOF). Colonies that could not be identified by mass spectrometry were identified by amplification and molecular sequencing of a part of the 16s rRNA gene. Bacteria were recovered from 100% of oral swabs; 220 isolates of 35 different genera of bacteria were cultured. The most frequently isolated bacteria were Streptococcus sp. (19.8%), Rothia sp. (17.9%), Enterobacter sp. (7%), Staphylococcus sp. (6.6%) and Actinomyces sp. (5.7%). Four phyla are represented: Proteobacteria (38.3%), Firmicutes (30.5%), Actinobacteria (26.9%) and Bacteroidota (4.3%). A wide range of commensal bacteria are present in the mouths of rabbits. Bacterial cultures taken from cases of dental abscesses often reveal bacteria. Streptococcus sp., Staphylococcus sp. and Actinomyces sp. are frequently found in cultures from dental abscesses, in contrast to Rothia and Enterobacter species. Our findings enhance the knowledge of rabbit microbial communities throughout oral cavity.

Enhanced lignocellulose degradation and composts fertility of cattle manure and wheat straw composting by Bacillus inoculation

Few studies on Bacillus inoculation have been reported for lignocellulose degradation and composts fertility during composting. This research explored the enhanced lignocellulose degradation and composts fertility of cattle manure and wheat straw composting by Bacillus inoculation. Bacillus methylotrophicus F-6, Bacillus velezensis T-B, and Bacillus haynesii R-1 were used in this research. The results indicated that Bacillus inoculation (1) prolonged the thermophilic phase by 1–2 days, (2) decreased the NH+4-N/NO-3-N value, E4/E6, and respiration activity for four days (RA4) of final composts, (3) increased the cellulose, hemicellulose, and lignin degradation rate by 17.1%− 46.4%, 16.9%− 34.5%, and 30.6%− 69.4%, and (4) increased biomass of plant growth by 8.6%− 42.5% (based on final dry matter) and 16.4%− 42.4% (based on final organic matter). Pearson correlation analysis indicated that total nitrogen, total phosphorous, total potassium, and relative abundance of Atopostipes, Proteiniphilum and Thermobifida of final compost were positively correlated to the plant growth. Bacillus is a genus of thermophilic bacteria that can improve microbial biodiversity and population, further altering the physical and chemical properties of compost. The results showed Bacillus inoculation is beneficial to improve compost maturity, promote lignocellulose degradation, and improve composts fertility.

Analysis of microbial diversity in Muscat Hamburg wine and Shine-Muscat wine

Different microbes in grapes lead to different flavors of wine. There are many kinds of wine grapes. In this article, the microorganisms in the wine made by the Muscat Hamburg grape and the Shine-Muscat grape are analyzed by using high-throughput sequencing technology. The results indicate that there are 8 species of dominant bacteria phylum which are Bacteroidetes, Firmicutes, Proteobacteria, Actinobacteria, Acidobacteria, Epsilonbacteraeota, Fusobacteria and Chloroflexi , and 13 species of dominant bacteria genus in Muscat Hamburg wine. There are 7 species of dominant bacteria phylum which are Bacteroidetes、Firmicutes、Proteobacteria、Actinobacteria、Acidobacteria、Epsilonbacteraeota、Fusobacteria and 14 species of dominant bacteria genus in Shine-Muscat wine. The dominant fungi phylum of the two varieties of wine are Ascomycota, Basidiomycota and Zygomycota. There are 2 species of dominant fungi genus in Muscat Hamburg wine and 9 species of dominant fungi genus in Shine-Muscat wine. At the genus level, bacteria are more abundant than fungi in the dominant genera of microorganisms in these two varieties of wine, and the diversity at the genus level was higher than that at the phylum level.

Supplementation of exogenous bile acids improve antitrichomonal activity and enhance intestinal health in pigeon (Columba livia)

The study investigated the effects of supplementation of bile acids in drinking water on antitrichomonal activity, growth performance, immunity and microbial composition of pigeon. A total of 180 pairs of White King parent pigeons were randomly assigned to 5 treatments of 6 replications with 6 pairs of parent pigeons and 12 squabs in each replicate. The control (CON) group drank water without any additions. The metronidazole (MTZ) group drank water with 500 μg/mL metronidazole for 7 d and without any additions in other days. The else groups drank water with 500, 750, and 1,250 μg/mL bile acid (BAL, BAM, BAH) for 28 d. The results showed that Trichomonas gallinae (T. gallinae) in MTZ, BAL, BAM, and BAH groups were lower than that in CON group at 14, 21, and 28 d of parent pigeons (P < 0.05) and at 21 and 28 d of squabs (P < 0.05). Albumin and alanine transaminase in CON group were higher than those in MTZ, BAL, and BAH groups (P < 0.05). The levels of soluble CD8 were higher in MTZ and BAH groups compared with CON group (P < 0.05). The lesions in oral mucosa, thymus, liver, and spleen tissues of CON group could be observed. Abundance-based coverage estimator (ACE) index in BAH group was higher than that in CON and MTZ groups. Simpson index in CON and BAH groups was higher than MTZ group (P < 0.05). Lactobacillus was the highest colonized colonic bacteria in genera that were 77.21, 91.20, and 73.19% in CON, MTZ, and BAH, respectively. In conclusion, drinking water supplemented with 500, 750, and 1,250 μg/mL bile acid could inhibit growth of T. gallinae in both parent pigeons and squabs. Squabs infected with T. gallinae in control group had higher mortality rate and more serious tissue lesions. Squabs in bile acids treated group had more sCD8 in serum and abundant intestinal morphology. Bile acids could be an efficient drinking supplements to inhibit T. gallinae and improve pigeon adaptive immunity and intestinal health.

Bacteriological Assessment of Smoked-Dried White Shrimp (Nematopalaemon hastatus Aurivillius, 1898) Sold in Calabar, Nigeria

Aim: Enumeration of bacterial counts is an important index of assessing the safety and quality of food products. This study aimed to investigate the occurrence of pathogenic bacteria in white shrimp samples obtained from major markets serving consumers in Calabar.&#x0D; Study Design: This study was a cross sectional study conducted between April 2017 and April 2018.&#x0D; Methodology: One hundred and twenty (120) samples of smoked dried Nematopalaemon hastatus (white shrimp) were analyzed for the presence of bacterial pathogens. Bacterial loads and identification of isolated organisms was determined using standard microbiological methods.&#x0D; Results: The results showed that 66.7% of the analyzed shrimps had aerobic bacterial counts exceeding the upper permissible limit (&lt;1.0x106Cfu/g) and 56.7% had unsatisfactory (˃20Cfu/g) Vibrio counts. The study revealed the presence of different bacteria genera namely Klebsiella, Salmonella, Pseudomonas, Serratia, Vibrio, Citrobacter, Proteus, Aeromonas, Streptococcus, Escherichia, Coagulase-negative Staphylococci (CoNS), Enterobacter and Bacillus. Predominant organism was Salmonella spp (26.7%), followed by Vibrio spp (21.7%) while the least isolated organisms were Bacillus spp and Coagulase-Negative Staphylococci (1.7%) each. The occurrence of high counts of pathogens in seafood may cause food poisoning; especially in individuals who consume this seafood raw, or lightly or insufficiently cooked.&#x0D; Conclusion: Hence, seafood should be processed and packaged under standard hygienic conditions to reduce the risk of microbial contamination. In addition, public health awareness campaign targeted at consumers and vendors should be optimized with frequent monitoring by regulatory agencies.

Correlation between caries activity and salivary microbiota in preschool children.

Early childhood caries (ECC) is the most common chronic infectious oral disease in preschool children worldwide. It is closely related to the caries activity (CA) of children. However, the distribution characteristics of oral saliva microbiomes in children with different CA are largely underexplored. The aim of this study was to investigate the microbial community in saliva of preschool children with different CA and caries status, and to analyze the difference of microbial community in saliva of children with different CA and its correlation with ECC. Subjects were divided into 3 groups based on the Cariostat caries activity test: Group H, high CA (n=30); Group M, medium CA (n = 30); Group L, low CA (n=30). Questionnaire survey was used to explore the related influencing factors of CA. According to the caries status (on the basis of decayed mising filled teeth), these subjects were divided into caries-free group (dmft=0, n=19), caries-low group (0 < dmft ≤ 4, n=27) and caries-high group (dmft > 4, n=44). Microbial profiles of oral saliva were analyzed using 16S rRNA gene sequencing. There were significant differences in the microbial structure (P < 0.05). Scardovia and Selenomonas were the biomarkers of both H group and high caries group. The genus Abiotrophia and Lautropia were the biomarkers of both the L group and the low caries group, while the Lactobacillus and Arthrospira spp. were significantly enriched in the M group. The area under the ROC curve of the combined application of dmft score, age, frequency of sugary beverage intake, and the genus Scardovia, Selenomonas, and Campylobacter in screening children with high CA was 0.842. Moreover, function prediction using the MetaCyc database showed that there were significant differences in 11 metabolic pathways of salivary microbiota among different CA groups. Certain bacteria genera in saliva such as Scardovia and Selenomonas may be helpful in screening children with high CA.

Influence of double-layer filling structure on nitrogen removal and internal microbial distribution in bioretention cells

The nitrogen removal effect of traditional bioretention cells on runoff rainwater is not stable. The nitrogen removal effect of bioretention cells can be improved by setting up a layered filling structure, but the effect of changes in filling structure on the nitrogen removal process and microbial community characteristics is still unclear. Two types of porosity fillers were set up in the experiment, and a homogeneous bioretention cell and three bioretention cells with layered fillers were constructed by changing the depth range of the upper and lower layers to analyze the influence of the pore variation of different depth fillers on the nitrogen removal process and microbial community characteristics. The experimental results showed that, compared with the homogeneous filing structure, the layered filling structure can strengthen the adsorption of NH4+-N and the conversion of NO3−-N, so as to increase the removal rates of NH4+-N and NO3−-N by 20.71–81.56% and 9.25%–78.19%, respectively. Although the low porosity filler structure will reduce the nitrification activity and urease activity by 48.63%–66.68% and 8.00%–20.64% respectively, it can increase the denitrification activity by 19.14%–31.92%, thus significantly reducing the nitrate content in the filler. The low porosity filler structure can affect the growth and reproduction of various phylum bacteria such as Proteobacteria, Chloroflexi, Acidobacteria, and genus bacteria such as Nitrospira, Ellin6067, Rhizobacter, Pseudomonas, which can improve the diversity and richness of microorganisms.

Pilot-scale two-phase anaerobic digestion of deoiled food waste and waste activated sludge: Effects of mixing ratios and functional analysis

Anaerobic co-digestion of deoiled food waste (dFW) and waste activated sludge (WAS) can address the challenges derived from mono-digestion of FW. In the present study, a pilot-scale methanogenic bioreactor of a two-phase anaerobic digestion system was developed to explore the impact of dFW/WAS volatile solids ratios on the overall performance, microbial community, and metabolic pathways. Besides, the tech-economic of the system was analyzed. The results showed that the degradation efficiency of soluble chemical oxygen demand (SCOD) was more than 84.90% for all the dFW/WAS ratios (v/v) (1:0, 39:1, 29:1, 19:1 and 9:1). Moreover, the dominant genus of bacteria and archaea with different ratios were Lactobacillus (66.84–98.44%) and Methanosaeta (53.66–80.09%), respectively. Co-digestion of dFW and WAS (29: 1 in v/v ratios) obtained the highest yield of methane (0.41 L CH4/Ladded) with approximately 90% of SCOD being removed. In the pilot-scale experiment, the co-digestion of FW and WAS makes positive contribution to reusing solid waste for improving solid management.

Antibiotic Resistance and Detection of Blatem and MecA Genes in Bacteria Isolated from Street Vended Pounded Yam in Yenagoa, Nigeria

Antibiotic resistant pathogens spread through food are a public health concern. The aim of this study was to determine the profile of antibiotic resistance and to investigate the presence of genes that produce antibiotic resistance in bacterial isolates from pounded yam collected from five sites in Yenagoa, Nigeria (Swali, Amarata, Kpansia, Tombia, and Akenfa). The Kirby-Bauer disk diffusion method was used to examine antibiotic susceptibility to nine antibiotics (Augmentin, Ofloxacin, Chloramphenicol, Ampicillin, Erythromycin, Gentamycin, Nitrofuratoin, Streptomycin and Tetracyclin), and the PCR method was utilized to find the blaTEM and mecA genes. A total of 150 pounded yam samples were collected and analyzed. Shigella spp, Bacillus spp, Staphylococcus spp, Pseudomonas spp, Salmonella spp, Klebsiella spp, Proteus spp, and Escherichia coli are among the bacteria that were recovered from the pounded yam samples. Except for Pseudomonas spp., all tested positive for multidrug resistance (resistance to three or more tested antibiotics), with the majority of these antibiotics being Chloramphenicol, Ampicillin, Erythromycin, Gentamycin, Nitrofuratoin, Streptomycin, and Tetracyclin. The Escherichia coli isolated from the street-vended pounded yam exhibited multidrug resistance against Ampicillin (37.5%), Erythromycin (43.8), Gentamycin (34.4), Streptomycin (21.9) and Tetracyclin (40.6). Bacillus spp also showed multidrug resistance against Chloramphenicol (36.4), Ammpicillin (36.4), Erythromycin (45.5), Gentamycin (36.4), Nitrofuratoin (36.4), Streptomycin (27.3) and Tetracyclin (36.4). Inhibition zones against Augmentin, Ofloxacin, Chloramphenicol, Ampicillin, Erythromycin, Gentamycin, Nitrofuratoin, Streptomycin, and Tetracyclin were clearly visible in Pseudomonas spp (100, 96.4, 64.3, 50.0, 82.1, 75.0, 64.3, 92.9, and 50.0% respectively). The highest resistance by number of bacterial isolates was found in Erythromycin (6 isolates showed resistance), followed by Tetracyclin (5 isolates showed resistance). Ampicillin and Streptomycin resistance was present in four isolates. Three representative isolates were selected for molecular identification of blaTEM and mecA which were amplified at 600bp and 500bp respectively. These genes were responsible for the antibiotic resistance seen in the isolates. According to this study, the pounded yam samples that were evaluated had food-borne disease strains that are multidrug resistant and a danger to the general public's health. The findings cast doubt on the quality of foods sold on the streets of Yenagoa, Nigeria.