Microplastics (<5 mm) exhibit intrinsic features such as density, hydrophobic surface, or high surface/volume ratio, that are known to promote microbial colonization and biofilm formation in marine ecosystems. Yet, a relatively low number of studies have investigated the nature of microplastic associated bacterial communities in coastal ecosystems and the potential factors influencing their composition and structure. Here, we characterized microplastics collected in the Bay of Brest by manual sorting followed by Raman spectroscopy and studied their associated bacterial assemblages using 16S amplicon high-throughput sequencing. Our methodology allowed discriminating polymer type (polyethylene, polypropylene and polystyrene) within small size ranges (0.3–1 vs. 1–2 vs. 2–5 mm) of microplastics collected. Data showed high species richness and diversity on microplastics compared to surrounding seawater samples encompassing both free living and particle attached bacteria. Even though a high proportion of operational taxonomic units (OTU; 94 ± 4%) was shared among all plastic polymers, polystyrene fragments exhibited distinct bacterial assemblages as compared to polyethylene and polypropylene samples. No effect of microplastic size was revealed regardless of polymer type, site and date of collection. The Vibrio genus was commonly detected in the microplastic fraction and specific PCR were performed to determine the presence of potentially pathogenic Vibrio strains (namely V. aestuarianus and the V. splendidus polyphyletic group). V. splendidus related species harboring putative oyster pathogens were detected on most microplastic pools (77%) emphasizing the need of further research to understand the role of microplastics on pathogen population transport and ultimate disease emergence.

Ballast water is used to safely stabilize and operate shipping vessels worldwide, in a multitude of aquatic settings, including inland, coastal and open oceans. However, ballast water may pose ecological, public health, and/or economic problems as it may serve as vehicles of transmission of microorganisms. Current ballast water regulations include limits of Escherichia coli, Enterococcus spp. and toxigenic Vibrio cholerae. Several United States Environmental Protection Agency approved standard operating protocols (SOPs) exist for detection of E. coli and Enterococci, yet none exists for V. cholerae. Current V. cholerae detection methods include colony blot hybridization, direct fluorescent antibody test (DFA), and/or polymerase chain reaction (PCR), which can be time consuming and difficult to perform. This study utilizes Cholera SMART II to determine its potential use in detection of V. cholerae. Validation of this method would help provide quick and accurate analysis for V. cholerae in ballast discharge waters in the field.

The relationship between land use and microbial community structure at seven sites along the Lower Mekong River, between Thailand and the Loa People’s Democratic Republic, was investigated using Illumina next-generation sequencing of the V5–V6 hypervariable regions of the 16S rRNA gene. In total, 14,470 operational taxonomic units (OTUs) were observed. Community composition was significantly different between sampling years. Moraxellaceae and Comamonadaceae were the predominant bacterial families in upstream sites, which included agricultural and urban areas in the Loei and Nong Khai provinces of Thailand. Members of the family Comamonadaceae were prevalent in agricultural and urban sites in Bueng Kan Province, while Moraxellaceae and Burkholderiaceae were the major families in a site downstream of an urban area in the Nakhon Phanom Province of Thailand. The bacterial community observed from a forested area of Patam National Park in Thailand showed greatest diversity, and several major bacterial families including Comamonadaceae, Moraxellaceae, and Pseudomonadaceae were more dominant than other sites. The diversity of fecal indicator bacteria, determined by ERIC-PCR DNA fingerprinting, indicated the presence of 29 strains of Escherichia coli and 21 strains of Enterococcus, while TP-RAPD patterns represented six species of Enterococcus. Results of this study indicated that although the difference in the distribution of bacterial phyla and families was found among sampling sites, the bacterial community composition, based on the presence of OTUs, continuously retained its signature across approximately 758 km along the Lower Mekong River, regardless of the type of land use. Water parameters, including temperature, turbidity, DO, and air temperature, also differentially affected the abundance of bacterial families along the Mekong River.

Mitochondria play an essential role to supply the cell with metabolic energy in the form of adenosine triphosphate (ATP) through oxidative phosphorylation (OXPHOS). As a consequence, they are also the primary source of cellular reactive oxygen species (ROS) which can cause oxidative damage of individual respiratory chain complexes. Indeed, affected OXPHOS subunits result in decreases in ATP production and increases in ROS formation which generate oxidative phosphorylation deficiency leading to mitochondrial dysfunctions. It has been suggested that ROS play a vital role in the pathogenesis of mitochondrial diseases. To the best of our knowledge, this is the first study which aimed to investigate the genetic variant effect of the antioxidant enzymes GSTM1 and GSTT1 on mitochondrial disease among a Tunisian population. In this report, 109 patients with mitochondrial disease and 154 healthy controls were genotyped by multiplex PCR amplification, and data were analyzed by SPSS v20 software. The results showed that GSTM1 null genotype was found to be associated with mitochondrial disease with a protective effect; however, no significant association of GSTT1 polymorphism with mitochondrial disease risk was revealed. But, interestingly, our findings highlight that GSTM1 active and GSTT1 null genotype combination increased by three fold the risk of developing mitochondrial disease with p c = 0.020, notably mitochondrial myopathy with p c = 0.046 and Leigh syndrome with p c = 0.042. In conclusion, this study suggests that GSTM1 active and GSTT1 null genotype combination might be a risk factor in developing mitochondrial disease.

Maize fields near Mae Tao Creek in Pha Te Village, Tak Province, Thailand are contaminated with Zn, Cd, and Pb. This research studied the interaction between levels of the metals contaminating the soil and maize development, heavy metal accumulation in the seeds, and the soil bacterial community structure. Our field experiment was carried out in five plots with metal contents that gradually decreased from a high level near the creek to a lower level further into the land: Zn 380–4883 mg kg⁻¹, Cd 6–85 mg kg⁻¹, and Pb 34–154 mg kg⁻¹. Cultivation and isolation on nutrient agar (NA) was utilized to study the culturable bacterial community, and polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) was utilized for the unculturable bacterial communities. All statistical analyses clearly indicated that rainfall and irrigation were the main factors affecting total Zn concentration and bioavailable Zn, Cd, and Pb in the field. The variation in the contents of the heavy metals was weakly correlated with the culturable bacterial community indices (Shannon-Wiener, evenness and richness), but the contents resulted in a difference in the overall diversity of the bacteria in the soil. The richness, numbers of culturable rhizobacteria, and maize growth stage significantly affected the amount of Zn and Cd that accumulated in the roots. In addition, maize accumulated a high level of Zn in the seeds, while the low contents of Cd and Pb in the seeds were below our limit of detection. The results obtained could be informative for the management of maize cultivation in the area.

The aim of the study was to determine the antimicrobial resistance profile and the occurrence of extended-spectrum beta-lactamase genes and to analyze the genetic diversity of Escherichia coli strains isolated from the environment of horse riding centers. The study was conducted using E. coli strains isolated from the air, manure, and horse nostril swabs in three horse riding centers differing in the system of horse keeping—stable (OJK Pegaz and KJK Szary) and free-range (SKH Nielepice). Resistance to antibiotics was determined using the disk-diffusion method, and the PCR technique was employed to detect the extended-spectrum β-lactamase (ESBL) genes, while the genetic diversity of strains was assessed by rep-PCR. A total of 200 strains were collected during the 2-year study, with the majority isolated from KJK Szary, while the smallest number was obtained from SKH Nielepice. The strains were mostly resistant to ampicillin, aztreonam, and ticarcillin. The tested strains were most frequently resistant to one or two antibiotics, with a maximum of ten antimicrobials at the same time. Two multidrug-resistant (MDR) strains were detected in OJK Pegaz while in KJK Szary there were two MDR and one extensively drug-resistant (XDR) strain. The ESBL mechanism was most frequently observed in OJK Pegaz (20.31% of strains) followed by KJK Szary (15.53% of strains) and SKH Nielepice (15.15% of strains). Among the ESBL-determining genes, only blaTEM and blaCTXM-9 were detected—blaTEM was mostly found in KJK Szary (53.40% of strains), while the second detected gene—blaCTXM-9—was most frequent in SKH Nielepice (6.06% of strains). The rep-PCR genotyping showed high variation among the analyzed strains, whereas its degree differed between the studied facilities, indicating that the type of horse keeping (stable vs. free-range) affects the genetic diversity of the E. coli strains. Having regard to the fact that the tested strains of E. coli were derived from non-hospitalized horses that were not treated pharmacologically, we can assume that the observed antimicrobial resistance may be of both—natural origin, i.e., not the result of the selection pressure, and acquired, the source of which could be people present in the horse riding facilities, the remaining horses which were not included in the study, and air, as well as water, fodder, and litter of the animals. Therefore, it can be concluded that the studied horses are the source of resistant E. coli and it is reasonable to continue monitoring the changes in antimicrobial resistance in those bacteria.

Untreated wastewater is a risk factor for the spread of antibiotic resistance in the environment. However, little is known about the contribution of untreated wastewater to the burden of antibiotic resistance in the Nigerian environment. In this study, a total of 143 ceftazidime-/cefpodoxime-resistant bacteria isolated from untreated wastewater and untreated wastewater-contaminated surface and groundwater in Nigeria were screened for extended-spectrum β-lactamase (ESBL) genes, integrons and integron gene cassettes by PCR. The genetic environment of bla CTX₋M₋₁₅ was mapped by PCR and potentially conjugative plasmids were detected among the isolates by degenerate primer MOB typing (DPMT). ESBL production was confirmed in 114 (79.7%) isolates and ESBL genes (bla SHV, bla CTX₋M₋₁₅ and bla TEM) were detected in 85 (74.6%) ESBL-producing isolates. bla CTX₋M₋₁₅ was associated with ISEcp1 and with orf477 in 12 isolates and with ISEcp1, IS26 and orf477 in six others. To the best of our knowledge, this is the first report of bla CTX₋M₋₁₅ in hand-dug wells and borehole serving as sources of drinking water and a first report of the genetic environment of bla CTX₋M₋₁₅ in environmental bacteria from Nigeria. The results of this study confirm untreated wastewater as an important medium for the spread of ESBL-producing bacteria within the Nigerian environment. Hence, the widespread practice of discharging untreated wastewater into the aquatic ecosystem in Nigeria is a serious risk to public health.

The devastating health effects of particulate matter (PM₁₀) exposure by susceptible populace has made it necessary to evaluate PM₁₀ pollution. Meteorological parameters and seasonal variation increases PM₁₀ concentration levels, especially in areas that have multiple anthropogenic activities. Hence, stepwise regression (SR), multiple linear regression (MLR) and principal component regression (PCR) analyses were used to analyse daily average PM₁₀ concentration levels. The analyses were carried out using daily average PM₁₀ concentration, temperature, humidity, wind speed and wind direction data from 2006 to 2010. The data was from an industrial air quality monitoring station in Malaysia. The SR analysis established that meteorological parameters had less influence on PM₁₀ concentration levels having coefficient of determination (R ²) result from 23 to 29% based on seasoned and unseasoned analysis. While, the result of the prediction analysis showed that PCR models had a better R ² result than MLR methods. The results for the analyses based on both seasoned and unseasoned data established that MLR models had R ² result from 0.50 to 0.60. While, PCR models had R ² result from 0.66 to 0.89. In addition, the validation analysis using 2016 data also recognised that the PCR model outperformed the MLR model, with the PCR model for the seasoned analysis having the best result. These analyses will aid in achieving sustainable air quality management strategies.

Giardia and Cryptosporidium are potentially pathogenic protozoa which are ubiquitous in ambient surface water. The present study included 60 samples of surface water from three sampling sites from the Rímac River, Lima and Callao, Peru, to detect the occurrence of Giardia spp. and Cryptosporidium spp. and to perform molecular characterization of specimens found. Water samples were concentrated using the membrane filtration technique, and following elution, cysts and oocysts were visualized by direct immunofluorescence assay (IFA). For molecular characterization, tpi and bg gene fragments and 18S rRNA were amplified by nested PCR for Giardia and Cryptosporidium, respectively, followed by sequencing and phylogenetic analysis. Giardia cysts were found in 93.3% of the analyzed samples, whereas Cryptosporidium oocysts were detected in 15%. The positivity of the Giardia cysts was 86.6% (n = 26) in 2014, while Cryptosporidium oocysts were not detected. In 2015, both protozoa were found in raw water samples, with all 30 samples collected positive for Giardia cysts (100.0%) and 9 positive for Cryptosporidium oocysts (30.0%). Oocysts were detected in 20.0% of water samples from sites 1 (mean 5.25 oocysts/L) and 2 (mean 52.3 oocysts/L), while at site 3, oocysts were detected in 50.0% of raw water samples (mean 193.6 oocysts/L). The presence of Giardia duodenalis assemblage A was confirmed in several samples by the phylogenetic positioning of the bg and tpi genes, and the sub-assemblage AII was predominant (8/9). Sequencing for Cryptosporidium resulted in profiles compatible with Cryptosporidium hominis, Cryptosporidium meleagridis, and Cryptosporidium baileyi. This is the first time that the presence of G. duodenalis assemblage A/sub-assemblage AII and Cryptosporidium species has been reported in surface water samples in Peru. These Cryptosporidium species and the Giardia duodenalis assemblage are associated with human disease which highlights the potential risk to public health and the need to increase environmental monitoring measures to protect this water body.

For the purpose of safe modulation of the intestinal microflora, probiotics have been increasingly used in recent years. In the present work, the effect of the probiotic sporobacterin (Bacillus subtilis 534) (I group) and soybean-bifidum (Bifidobacterium longum) (II group) on male rats of the Wistar line was evaluated. In assessing nonspecific immunity in vitro, there was an increase in the level of baseline level in the first and second groups (by 8.3 and 12.2% more control). The influence of probiotic preparations on the intestinal normoflora was assessed using PCR. Bifidumbacterin increased the normal microflora, in particular, Escherichia coli 1.55 times, Lactobacillus 1.26 times, Enterococcus 1.3 times as much control; the level of conditionally pathogenic microflora, in particular, Proteus spp. decreased by 1.3 times in comparison with the control. Sporobacterin also contributed to an increase in the amount of E. coli (1.55 times) and Lactobacillus (0.9 times). When a culture of Bifidobacterium longum was introduced, a selective reduction in the loss of chemical elements was observed against the background of the diet used. At the end of the experiment, the content of calcium in the body tissues of animals of group II exceeded this indicator in group I by 3.9%, phosphorus by 17.6%, copper by 28.5%, and zinc by 15.2%. The totality of the results obtained by us indicates that inclusion of Bifidumbacterium longum in the diet of animals makes the use of this preparation in the correction of mineral imbalance and improves the microflora of the intestines of animals by reducing the number of representatives of opportunistic microflora against the background of an increase in the number of basic representatives of normal microbiocenosis. Also, the use of probiotic drugs as additives leads to a slight increase in the level of nonspecific immunity, which increases the natural resistance of the organism.