Recreational water quality status of the Kidd's Beach as determined by its physicochemical and bacteriological quality parameters

Antimicrobial resistance characterization of Enterococcus faecium, Enterococcus faecalis and Enterococcus hirae isolated from marine coastal recreational waters in the State of São Paulo, Brazil

Coastal water quality is facing increasing threats due to human activities. Their contamination by sewage discharges poses significant risks to the environment and public health. We aimed to investigate the presence of antibiotic-resistant Enterococcus in beach waters. Over a 10-month period, samples were collected from four beaches in the State of São Paulo (Brazil). Enterococcus isolates underwent matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS) and molecular analysis for accurate genus and species identification. The antimicrobial susceptibility for 14 antibiotics was evaluated using the disc diffusion method followed by a multidrug-resistance (MDR) classification. PCR amplification method was used to detect antimicrobial resistance genes (ARGs). Our findings revealed the prevalence of Enterococcus faecalis, E. faecium and E. hirae. Out of 130 isolates, 118 were resistant to multiple antibiotics. The detection of resistance genes provided evidence of the potential transfer of antibiotic resistance within the environment. Our findings underscore the necessity for continuous research and surveillance to enhance understanding of the pathogenicity and antimicrobial resistance mechanisms of Enterococcus, which is crucial to implement effective measures to preserve the integrity of coastal ecosystems.

Prevalence of Class 1 Integron and In Vitro Effect of Antibiotic Combinations of Multidrug-Resistant Enterococcus Species Recovered from the Aquatic Environment in the Eastern Cape Province, South Africa

Enterococci are regarded as a better indication of faecal pollution in freshwater and marine waters. Their levels in seawater are positively connected with swimming-related gastrointestinal disorders. This study used an Enterococcus-specific polymerase chain reaction (PCR) to characterize the isolates. Classes 1 and 2 integrons were examined for environmental Enterococcus isolates using a standard biological procedure. All strains were assessed against a panel of 12 antibiotics from various classes using disc diffusion methods. The microdilution method was used to work out the minimum inhibitory concentration (MIC) according to the CLSI guiding principles. The combination therapy of the resistant drugs was evaluated using a checkerboard assay and a time-dependent test for assessing their bactericidal or bacteriostatic activity. The gene diversity of the tested organisms was analyzed with the aid of Enterobacterial Repetitive Intergenic Consensus (ERIC) PCR. In total, 57 Enterococcus spp. environmental samples were recovered, in which Enterococcus faecalis (33.33%) and Enterococcus faecium (59.65%) were the dominant species. Resistance to linezolid, ciprofloxacin, erythromycin, gentamicin, vancomycin, rifampicin, and tetracycline was prevalent. Fifty (50) strains tested positive for class 1 integron, more frequent in Enterococcus faecium and Enterococcus faecalis isolates, with no gene cassette array discovered. A combination of gentamicin (MIC 4 µg/mL) with vancomycin (MIC 256 µg/mL) antibiotics against Enterococcus faecalis showed antibacterial activity. In contrast, the combination of ciprofloxacin (1 µg/mL) with Ampicillin (16 µg/mL) antibiotics against Enterococcus faecalis showed a bacteriostatic effect. The ERIC-PCR analysis pointed out that most of the assessed isolates have close genetic similarities.

The emergency discharge of sewage to the Bay of Gdańsk as a source of bacterial enrichment in coastal air

The purpose of this research was to study the presence of potential pathogenic bacteria in the seawater and air in five coastal towns (Hel, Puck, Gdynia, Sopot, Gdańsk-Brzeźno) as well as the enrichment of bacteria from the seawater into the coastal air after an emergency discharge of sewage into the Bay of Gdańsk. A total of 594 samples of air and seawater were collected in the coastal zone between spring and summer (between 2014 and 2018). Air samples were collected using the impact method with a SAS Super ISO 100. The multivariate analysis, conducted using contingency tables, showed a statistically significant variation between the concentration of coliforms, psychrophilic and mesophilic bacteria in the seawater microlayer and air in 2018, after an emergency discharge of sewage into the Bay of Gdańsk, compared to 2014-2017. Moreover, we detected a marine aerosol enrichment in psychrophilic, mesophilic bacteria, coliforms and Escherichia coli. We also showed a statistically significant relationship between the total concentration of bacteria and humidity, air temperature, speed and wind direction. This increased concentration of bacteria in the seawater and coastal air, and the high factor of air enrichment with bacteria maybe associated with the emergency discharge of wastewater into the Bay of Gdańsk. Therefore, it is suggested that in the event of a malfunction of a sewage treatment plant, as well as after floods or sudden rainfall, the public should be informed about the sanitary and epidemiological status of the coastal waters and be recommended to limit their use of coastal leisure areas.

Ecological and human health risk assessment of total petroleum hydrocarbons in surface water and sediment from Woji Creek in the Niger Delta Estuary of Rivers State, Nigeria

This study was designed to assess total petroleum hydrocarbon (THP) concentrations in the surface water and sediment sampled from Woji Creek and to assess potential ecological and human health risk due to petroleum hydrocarbons along the creek. Physicochemical parameters [pH, temperature (T), electrical conductivity (EC), dissolved oxygen (DO), total dissolved solids (TDS)] were in-situ measured from sediment and surface water; hydrological parameters (width, depth and volume) were used to calculate the flow rate (discharge) at different stations of the creek. Trend of TPH in the surface water samples along the creek were as follows: St4 (3.639 ± 1.121 mg/L) > St3 (2.449 ± 0.623 mg/L) > St1 (1.457 ± 0.244 mg/L) > St2 (1.069 ± 0.228 mg/L) > St5 (1.010 ± 0.120 mg/L) Trend of TPH concentration across the creek was as follows: St1 - 8.758 ± 0.697 mg/kg > St3 - 7.675 ± 0.541 mg/kg > St5 - 5.515 ± 0.401 mg/kg > St4 - 5.075 ± 0.363 mg/kg > St2 - 3.162 ± 0.307 mg/kg. Diagnostic indices indicate that the hydrocarbon in the creek was from petrogenic source. Estimation of ecological risk indicated risk in the surface water but not in the sediment. However, human health risk assessment indicated no risk due to human ingestion of the sediment or surface water.