Bacterial community in Sinonovacula constricta intestine and its relationship with culture environment.

Although the importance of intestinal microbes to aquaculture animals has been recognized, the intestinal bacteria of Sinonovacula constricta and its culture environment are rarely studied. In this study, high-throughput sequencing was used to explore the intestinal bacterial communities of pond water, sediment, and S. constricta intestine. Significance analysis and principal coordinates analysis (PCoA) showed that there were significant differences in bacterial communities among animals' intestine, pond water, and sediment (p < 0.05). Venn analysis showed that intestinal bacteria shared a considerable number of OTUs (operational taxonomic units) with the sediment and water. SourceTracker analysis suggested that the contribution of sediment to the intestinal bacteria of S. constricta was much larger than that of rearing water. The Kruskal-Wallis test showed that the dominant bacterial taxa differed significantly between animals' intestines and the pond environment, and each of them has a unique bacterial composition. A network diagram indicated the complex positive and negative interactions between intestinal bacteria at the OTU level. Furthermore, BugBase analysis indicated that the bacterial contribution to potential pathogens in the animals' intestines is similar to that in sediments, suggesting that sediment was the main source of potential pathogens in S. constricta intestine. This study provided a theoretical basis for environmental regulation and disease prevention of S. constricta in aquaculture. KEY POINTS: • Culture environment had a significant effect on the intestinal bacterial community in S. constricta. • Sediment was a major source of intestinal bacteria and potentially pathogenic bacteria. • Complex positive and negative interactions existed between intestinal bacteria.

Vaginal colonisation of women in labour with potentially pathogenic bacteria: a cross sectional study at three primary health care facilities in Central Uganda.

BACKGROUND: Potentially pathogenic bacteria that colonise the lower genital tract of women in labour can be passed to the baby during birth. While many babies become colonised with these bacteria after delivery, a few develop neonatal infections. The lower genital tract is a reservoir for potential pathogens and a source of infection for neonates. We determined the prevalence of vaginal colonisation of potentially pathogenic bacteria among women in labour in Central Uganda and identified potential risk factors associated with this colonisation. METHODS: We conducted a cross sectional study at three primary health care facilities and collected vaginal swabs from HIV-1 negative women in labour. Specimens were cultured on different selective microbiological media, and biochemical tests were used to classify bacterial isolates on the species level. Multivariable logistic regression analyses were used to estimate the association between relevant exposures and colonisation with potentially pathogenic bacteria. RESULTS: We recruited 1472 women in labour whose mean age was 24.6 years (standard deviation [SD] 4.9). Of these, 955 (64.9%; 95% Confidence Interval [CI] 62.4, 67%) were vaginally colonised with at least one potentially pathogenic bacterial species. The most commonly isolated species were Escherichia coli (n = 508; 34.5%), Klebsiella pneumoniae (n = 144; 9.8%) and Staphylococcus aureus (n = 121; 8.2%). Results from exploratory multivariable regression analyses indicated that having had ≥5 previous pregnancies (adjusted odds ratio [aOR] 0.59; 95% CI 0.35, 0.97) or being ≥30 years old (aOR 1.52; 95% CI 1.03, 2.23) could be associated with vaginal colonisation with any potentially pathogenic bacteria, as well as with vaginal colonisation with S. aureus (aOR 0.33; 95% CI 0.12, 0.88, and aOR 2.17; 95% CI 1.17, 4.00, respectively). Possession of domestic animals in a household (aOR 0.57; 95% CI 0.35, 0.92) could be associated with vaginal colonisation with E. coli. CONCLUSIONS: Two-thirds of HIV-1 negative women in labour were vaginally colonised by potentially pathogenic bacteria, mainly E. coli, K. pneumoniae, and S. aureus.

Diverse sources of fecal contamination in macroalgae wrack-affected environment adjacent to river outflow along the Baltic Sea coast.

We investigated the dynamics of feces-associated microorganisms in areas with wrack accumulation in the southeastern part of the Baltic Sea. Our study covered single-day (2021 ) and multi-day (2022) observations during the recreational season. We collected water, sand, and wrack samples and assessed the abundance of fecal indicator bacteria (FIB), as well metagenomic analysis was conducted to monitor changes in microbial composition. Based on metagenomic data we identified taxa associated with feces, sewage, and ruminant sources. Human-related fecal pollution based on genetic markers correlated with the presence of Lachnospiraceae, Prevotellaceae and Rickenellacea abundance. Higher abundance and diversity of feces-associated and ruminant-associated taxa and the presence of enteric pathogens were observed when wrack accumulated near the river outflow in 2021, suggesting a potential link with fecal pollution from the river. As a preventive measure, it is recommended to remove the wrack to reduce the risk of exposure to potential enteric pathogens if it is accumulated next to the river outflow.

Impact of Season on Intestinal Bacterial Communities and Pathogenic Diversity in Two Captive Duck Species.

Vertebrates and their gut bacteria interact in complex and mutually beneficial ways. The intestinal microbial composition is influenced by several external influences. In addition to food, the abiotic elements of the environment, such as temperature, humidity, and seasonal fluctuation are also important determinants. Fecal samples were collected from two captive duck species, Baikal teal (Sibirionetta formosa) and common teal (Anas crecca) across four seasons (summer, autumn, winter, and spring). These ducks were consistently fed the same diet throughout the entire experiment. High throughput sequencing (Illumina Mi-seq) was employed to analyze the V4-V5 region of the 16sRNA gene. The dominant phyla in all seasons were Proteobacteria and Firmicutes. Interestingly, the alpha diversity was higher in winter for both species. The NMDS, PCoA, and ANOSIM analysis showed the distinct clustering of bacterial composition between different seasons, while no significant differences were discovered between duck species within the same season. In addition, LefSe analysis demonstrated specific biomarkers in different seasons, with the highest number revealed in winter. The co-occurrence network analysis also showed that during winter, the network illustrated a more intricate structure with the greatest number of nodes and edges. However, this study identified ten potentially pathogenic bacterial species, which showed significantly enhanced diversity and abundance throughout the summer. Overall, our results revealed that season mainly regulated the intestinal bacterial community composition and pathogenic bacteria of captive ducks under the instant diet. This study provides an important new understanding of the seasonal variations in captive wild ducks' intestinal bacterial community structure. The information available here may be essential data for preventing and controlling infections caused by pathogenic bacteria in captive waterbirds.

The Influence of Commercial Feed Supplemented with Carnobacterium maltaromaticum Environmental Probiotic Bacteria on the Rearing Parameters and Microbial Safety of Juvenile Rainbow Trout.

The aim of this study was to determine the effect of commercial feed (CF) supplemented with 0.1% of the Carnobacterium maltaromaticum environmental probiotic strain on the rearing parameters, apparent nutrient digestibility, and microbial safety of juvenile rainbow trout (Oncorhynchus mykiss). The fish were fed CF (control group, CG) and experimental feed (EF) supplemented with 0.1% of C. maltaromaticum (experimental group, EG) for 56 days. The final body weight and total body length of the fish were measured. The growth rate, condition factor, feed conversion ratio, viscerosomatic and hepatosomatic indices, and apparent digestibility coefficients of protein (PAD), lipids (LAD), ash (AAD), and nitrogen-free extract (NFEAD) were calculated. The total viable counts of C. maltaromaticum bacteria, mesophilic bacteria, hemolytic mesophilic bacteria, Pseudomonas fluorescens, Aeromonas hydrophila, Staphylococcus sp., and sulfite-reducing anaerobic spore-forming Clostridium sp. were determined in digestive tract contents and the skin of fish. Feed supplementation with C. maltaromaticum significantly affected most rearing parameters, as well as the PAD, LAD, AAD and NFE values, and bacterial counts. The principal component analysis (PCA) revealed significant positive correlations (p < 0.05) between fish growth rates, PAD and LAD values vs. C. maltaromaticum counts in the EF and in the digestive tract contents of the fish.

Selective Utilization of the Human Milk Oligosaccharides 2'-Fucosyllactose, 3-Fucosyllactose, and Difucosyllactose by Various Probiotic and Pathogenic Bacteria.

Prebiotic human milk oligosaccharides (HMOs) are found in human milk, which are not digested by infants but are metabolized by beneficial gut bacteria. We determined the ability of 57 bacterial strains within the Family Lactobacillaceae and genera Bifidobacterium and Bacteroides and potentially pathogenic bacteria to ferment the HMOs 2'-fucosyllactose, 3-fucosyllactose, and difucosyllactose. In addition, prebiotic galacto-oligosaccharides (GOS), lactose, fucose, and glucose were evaluated as carbon sources for these bacterial strains. Bacterial growth was monitored using the automatic Bioscreen C system. Only certain bifidobacteria, such as Bifidobacterium longum subsp. infantis and Bifidobacterium bifidum, as well as Bacteroides fragilis, Bacteroides vulgatus, and Bacteroides thetaiotaomicron utilized the studied HMOs as their sole carbon source, whereas almost all studied bacterial strains were able to utilize GOS, lactose, and glucose. The selectivity in utilization of HMOs by only certain bacteria can be advantageous by promoting beneficial microbes but not supporting the harmful pathogens in contrast to other less selective prebiotics.

Occurrence and distribution of fecal indicators and pathogenic bacteria in seawater and Perna perna mussel in the Gulf of Annaba (Southern Mediterranean).

The identification of fecal contamination in coastal marine ecosystems is one of the main requirements for evaluation of potential risks to human health. The objective of this study was to investigate the occurrence and distribution of fecal indicators and pathogenic bacteria in seawaters and mussels collected monthly during a period of 1 year from four different sites in Northeastern Algeria (sites S1 to S4), through biochemical and molecular analyses. Our research is the first to use molecular analysis to unambiguously identify the potentially pathogenic bacteria present in Algerian Perna perna mussels. The obtained results revealed that the levels of fecal indicator bacteria (FIB) from both P. perna and seawater samples largely exceeded the permissible limits at S2 and S3. This is mainly related to their location close to industrial and coastal activity zones, which contain a mixture of urban, agricultural, and industrial pollutants. Besides, P. perna collected from all sites were severalfold more contaminated by FIB than seawater samples, primarily during the warm season of the study period. Biochemical and molecular analyses showed that isolated bacteria from both seawater and mussels were mainly potentially pathogenic species such as E. coli, Salmonella spp., Staphylococcus spp., Klebsiella spp., Pseudomonas spp., and Proteus spp.

Comparison of keyboard colonization before and after use in an inpatient setting and the effect of keyboard covers.

Computer keyboards may contribute to patient infections. We cultured new keyboards, with/without keyboard covers, before placing them in adult inpatient rooms and recultured after 6 months. Nonpathogenic bacteria were present initially but potentially pathogenic bacteria were cultured only after use. Coagulase negative Staphylococcus colonization increased after use (P < .001). Keyboards with a cover had more potentially pathogenic bacteria (22% vs 16%), which although not significant statistically (P = .72), likely due to sample size, trended against covers offering protection.

Limited influence of primary treated sewage waters on bacterial abundance, production and community composition in coastal seawaters.

The response of bacteria in terms of abundance, production and community structure to changes induced by the discharge of primary treated sewage waters was investigated combining microbiological, chemical and molecular tools. The primary treatment did not affect substantially the bacterial community structure in wastewaters and did not reduce the concentrations of fecal indicators. The spatial distribution of the sewage plume was governed by vertical stratification and currents. Bacterial abundance and production in the sea receiving waste waters depended predominantly on environmental conditions. In the waters with the highest concentration of fecal pollution indicators the bacterial community was characterized by allochthonous bacteria belonging to Epsilonproteobacteria, Firmicutes, Gammaproteobacteria and Bacteroidetes. The latter two taxa were also present in unpolluted waters but had a different structure, typical for oligotrophic environments. Although the impact of primary treated sewage waters was limited, a sanitary risk persisted due to the relevant presence of potentially pathogenic bacteria.

High isolation rates of multidrug-resistant bacteria from water and carpets of mosques.

OBJECTIVE: There is little information regarding the isolation of antimicrobial-resistant potentially pathogenic bacteria from water and carpets of mosques worldwide. The objective of the present investigation is to determine the bacteriological quality of water and carpets of mosques in Elkhomes city in Libya. METHODS: Potentially pathogenic bacteria were isolated from water samples (n=44) and dust samples from carpets (n=50) of 50 mosques in Elkhomes city, Libya, using standard bacteriological procedures. Susceptibility of isolated bacteria to antimicrobial agents was determined by the disc-diffusion method. RESULTS: Of the water samples examined, 12 (27.3%) were positive for Escherichia coli, 10 (22.7%) for Klebsiella spp., and 15 (34.1%) for other enteric bacteria. Of the dust samples of carpets examined, 6 (12%) were positive for E. coli, 33 (66%) for Klebsiella spp., and 30 (60%) for Staphylococcus spp. Multidrug resistance (MDR, resistance to three or more antimicrobial groups) was found among 48.7% (19/37) and 46.9% (30/64) of the examined enterobacteria from water and carpets, respectively, and among 66.7% (20/30) of Staphylococcus spp. from carpets. In addition, methicillin-resistant Staphylococcus aureus (MRSA) was isolated from a carpet of one mosque. CONCLUSION: Presence of multidrug-resistant potentially pathogenic bacteria in examined water and carpets indicate that mosques as communal environments may play a role in the spread of multidrug-resistant bacteria in the community and pose a serious health risk to worshipers.

Detection of multiple potentially pathogenic bacteria in Matang mangrove estuaries, Malaysia.

The deltaic estuarine system of the Matang Mangrove Forest Reserve of Malaysia is a site where several human settlements and brackish water aquaculture have been established. Here, we evaluated the level of fecal indicator bacteria (FIB) and the presence of potentially pathogenic bacteria in the surface water and sediments. Higher levels of FIB were detected at downstream sampling sites from the fishing village, indicating it as a possible source of anthropogenic pollution to the estuary. Enterococci levels in the estuarine sediments were higher than in the surface water, while total coliforms and E. coli in the estuarine sediments were not detected in all samples. Also, various types of potentially pathogenic bacteria, including Klebsiella pneumoniae, Serratia marcescens and Enterobacter cloacae were isolated. The results indicate that the Matang estuarine system is contaminated with various types of potential human bacterial pathogens which might pose a health risk to the public.

Colonización faríngea por bacterias potencialmente patógenas en niños sanos de una escuela primaria / Nasopharyngeal colonization by potentially pathogenic bacteria found in healthy children from an elementary school

INTRODUCCIÓN: la nasofaringe humana es un reservorio natural de bacterias potencialmente patógenas, agentes etiológicos importantes de infecciones comunes que afectan a todas las edades, en particular a la población infantil. OBJETIVO: conocer la prevalencia de estos patógenos potenciales en niños sanos. MÉTODOS: tomando en cuenta las exigencias bioéticas establecidas para este tipo de estudio, en el año 2002 se realizó un estudio transversal descriptivo de portadores en 318 estudiantes de una escuela primaria de La Habana. A los escolares se les tomó un exudado de la faringe y los padres respondieron un cuestionario donde se indagó sobre factores de riesgo que influyen en el estado del portador (edad, sexo, hacinamiento, condición de fumador pasivo, antecedente de enfermedad respiratoria infecciosa o alérgica). La muestra se tomó en la escuela, se sembró directo en los medios de cultivo y las bacterias aisladas se identificaron por métodos convencionales y el sistema API NH. RESULTADOS: el porcentaje de portadores de bacterias potencialmente patógenas fue elevado (55 por ciento), prevalecieron: Staphylococcus aureus (33,6 por ciento), estreptococos b-hemolíticos (17,3 por ciento) y Streptococcus pneumoniae (11,6 por ciento). Dentro de los estreptococos b-hemolíticos predominó el grupo G (49 por ciento), seguidos del A y C con 18,2 por ciento de portadores en cada grupo. La edad fue un factor de riesgo significativo (p< 0,05), con porcentajes de portadores mßs elevados en los ni±os de 10 (60 por ciento), 11 (75,5 por ciento) y 12 a±os (77,3 por ciento). Existió resultado estadísticamente significativo entre los portadores de meningococo y el hacinamiento (p= 0,043). Predominó la asociación de S. aureus mßs estreptococos b-hemolíticos (27,9 por ciento), sobre todo en los ni±os alérgicos (p< 0,05). Neisseria lactamica se aisló en 29,6 por ciento e impidió la colonización por N. meningitidis (p= 0,0004). CONCLUSIONES: esta investigación...

INTRODUCTION: human nasopharynx is a natural reservoir of potentially pathogenic bacteria which are important etiological agents of common infections that affect all age groups, particularly the child population. OBJECTIVE: finding out the prevelance of these potential pathogens in healthy children. METHODS: Taking into account the bioethical requirement set for these kind of study in 2002, a descriptive cross-sectional study of carriers was performed on 318 pupils from an elementary school in Havana. Samples from their pharynx were taken for testing and their parents answered a questionnaire on the risk factors affecting the condition of the carrier (age, sex, crowding, passive smoking, history of infectious or allergic respiratory disease). The sample was taken at the school, then the smear was directly placed in the culture media and the isolated bacteria were identified by conventional methods and by the API NH system. RESULTS: the percentage of potentially pathogenic bacteria carriers was high (55 percent) in which Staphylococcus aureus (33.6 percent), hemolytic streptococci b (17.3 percent) y Streptococcus pneumoniae (11.6 percent). Among the hemolytic streptococci b, the group G (49 percent) predominated, followed by A and C with 18.2 percent of carriers in each group. Age was a significant risk factor (p< 0.05), being the highest percentages of carriers in children aged 10 (60 percent), 11 (75.5 percent) and 12 (77.3 percent) years. There was statistically significant relation between meningococcal carriers and crowding (p= 0.043). The association of S. aureus plus hemolytic streptococci b (27.9 percent) predominated, mainly in allergic children (p< 0.05). Neisseria lactamica was isolated in 29.6 percent and prevented the colonization by N. meningitidis (p= 0.0004). CONCLUSIONS: this research study made it possible to identify the patterns of nasopharyngeal colonization by potentially pathogenic bacteria in healthy...