Distribution of SARS-CoV-2 Genomes in Wastewaters and the Associated Potential Infection Risk for Plant Workers in Typical Urban and Peri-Urban Communities of the Buffalo City Region, South Africa.

The presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in wastewater has been reported in several studies and similar research can be used as a proxy for an early warning of potential Coronavirus disease 2019 (COVID-19) outbreaks. This study focused on profiling the incidence of SARS-CoV-2 genomes in wastewater samples obtained from facilities located in the Buffalo City Municipality. Raw samples were collected weekly using the grab technique for a period of 48 weeks. Ribonucleic acids were extracted from the samples, using the QIAGEN Powersoil Total RNA Extraction kit, and extracted RNA samples were further profiled for the presence of SARS-CoV-2 genomes using Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) technique. Furthermore, various environmental matrices were utilized to estimate the potential health risk to plant operators associated with exposure to SARS-CoV-2 viral particles using the quantitative microbiological risk assessment (QMRA) model. Our findings revealed the prevalence of SARS-CoV-2 genomes with concentrations that ranged from 0.22 × 103 to 17.60 × 103 genome copies per milliliter (GC/mL). Different exposure scenarios were employed for the QMRA model, and the findings indicate a probability of infection (P(i)) ranging from 0.93% to 37.81% across the study sites. Similarly, the P(i) was highly significant (p < 0.001) for the 20 mL volumetric intake as compared to other volumetric intake scenarios, and high P(i) was also observed in spring, autumn, and winter for all WWTPs. The P(i) was significantly different (p < 0.05) with respect to the different seasons and with respect to different volume scenarios.

Prevalence of multidrug-resistant Campylobacter species in wastewater effluents: A menace of environmental and public health concern.

The prevalence of multidrug-resistant Campylobacter species in wastewater effluents presents a formidable challenge at the intersection of environmental sustainability and public health. This study examined the presence of multidrug-resistant Campylobacter in wastewater effluents in the Eastern Cape Province, South Africa, and its implications for environmental ecosystems and public health. Forty-five samples from household effluent (HHE) and wastewater treatment plant effluent (WWTPE) were collected at different geographical locations within the province between April and September 2022. The counts of the presumptive Campylobacter genus ranged from 5.2 × 103 to 6.03 × 104 CFU/mL for HHE and 4.93 × 103 to 1.04 × 104 CFU/mL for WWTPE. About 42.55% of the samples were positive for Campylobacter species. Five virulence determinants including the cadF and wlaN were detected in all the isolates; however, flgR (19.23%), ciaB, and ceuE (15.38%) were less prevalent. The antibiogram profiles of confirmed Campylobacter isolates revealed high resistance (>55%) against all tested antibiotics ranging from 55.77% (nalidixic acid) to 92.30% (erythromycin), and resistance against the other antibiotics followed the order ciprofloxacin (51.92%), azithromycin (50%), and levofloxacin (48.08%). On the contrary, gentamicin was sensitive against 61.54% of the isolates, followed by imipenem (57.69%) and streptomycin (51.92%). The WWTPE's antibiotic resistance index (ARI) was 0.19, lower than the permitted Krumperman threshold of 0.2; and HHE's ARIs were higher. The isolates' respective multiple antibiotic resistance indexes (MARI) varied between 0.08 and 1.00. Among the phenotypically resistant Campylobacter isolates examined, 21 resistance determinants encoding resistance against ß-lactam, carbapenems, aminoglycosides, phenicol, quinolones, tetracyclines, and macrolides were detected, which explains the phenotypic resistance observed in the study. This study concludes that the wastewaters in the study areas are important reservoirs of multidrug-resistant and potentially pathogenic Campylobacter species, suggesting the need for proper treatment of the wastewaters to eliminate the organisms in the effluents before discharge the final effluent to the receiving watershed.

Prevalence, molecular characterization of integrons and its associated gene cassettes in Klebsiella pneumoniae and K. oxytoca recovered from diverse environmental matrices.

The high prevalence of infections arising from Klebsiella species is related to their ability to acquire and disseminate exogenous genes associated with mobile genetic elements such as integrons. We assessed the prevalence, diversity, and associated gene cassettes (GCs) of integrons in Klebsiella species. The isolates recovered from wastewater and hospital effluents, rivers, and animal droppings were identified using the conventional Polymerase Chain Reaction (PCR) with primers targeting the gryA, pehX, and 16S-23S genes. The antimicrobial resistance profile and the Extended-Spectrum and Metallo ß-lactamases production were carried out using standard microbiological techniques. PCR, DNA sequencing analyses, and Restriction Fragment Length Polymorphism were used to characterize the integrons and their associated GCs. Furthermore, the genotypic relationships between the different isolated K. pneumoniae were determined using Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR. About 98% (51/52) of the confirmed isolates harboured an integrase gene, with 80% intI1, while the remaining 20% concurrently harboured intI1 and intI2, with no intI3 observed. About 78% (40/51) of the bacterial strains were positive for a promoter, the P2R2, investigated, while 80% (41/51) harboured at least one of the qacEΔ1 and sul1. Three different GCs arrangements identified were aac(6')-Ib, aadA1-dfrA1, and dfrA1-sat2. At a similarity index of 60%, the ERIC-PCR fingerprints generated were categorized into nine clusters. Our study is the first to reveal the features of integrons in Klebsiella spp. recovered from environmental sources in the Eastern Cape Province, South Africa. We conclude that the organisms' sources are repositories of integrons harbouring various gene cassettes, which can be readily mobilized to other microorganisms in similar or varied niches.

Antimicrobial-Resistant Listeria monocytogenes in Ready-to-Eat Foods: Implications for Food Safety and Risk Assessment.

Antimicrobial resistance is an existential threat to the health sector, with far-reaching consequences in managing microbial infections. In this study, one hundred and ninety-four Listeria monocytogenes isolates were profiled for susceptibility using disc diffusion techniques. Possible foodborne listeriosis risk associated with ready-to-eat (RTE) foods (RTEF) and the risk of empirical treatment (EMPT) of L. monocytogenes infections, using multiple antimicrobial resistance indices (MARI) and antimicrobial resistance indices (ARI), respectively, were investigated. Twelve European Committee on Antimicrobial Susceptibility Testing (EUCAST) prescribed/recommended antimicrobials (EPAS) for the treatment of listeriosis and ten non-prescribed antimicrobials (non-PAS)] were evaluated. Antimicrobial resistance > 50% against PAs including sulfamethoxazole (61.86%), trimethoprim (56.19%), amoxicillin (42.27%), penicillin (41.24%), and erythromycin (40.21%) was observed. Resistance > 50% against non-PAS, including oxytetracycline (60.89%), cefotetan (59.28%), ceftriaxone (53.09%), and streptomycin (40.21%) was also observed. About 55.67% and 65.46% of the isolates had MARI scores ranging from 0.25-0.92 and 0.30-0.70 for EPAs and non-PAs, respectively. There was a significant difference (p < 0.01) between the MARI scores of the isolates for EPAs and non-PAs (means of 0.27 ± 0.21 and 0.31 ± 0.14, respectively). MARI/ARI scores above the Krumperman permissible threshold (>0.2) suggested a high risk/level of antimicrobial-resistant L. monocytogenes. The MARI risks of the non-success of empirical treatment (EMPT) attributed to EPAs and non-PAs were generally high (55.67% and 65.463%, respectively) due to the antimicrobial resistance of the isolates. MARI-based estimated success and non-success of EMPT if EUCAST-prescribed antimicrobials were administered for the treatment of listeriosis were 44.329% and 55.67%, respectively. The EMPT if non-prescribed antimicrobials were administered for the treatment of listeriosis was 34.53% and 65.46%, respectively. This indicates a potentially high risk with PAs and non-PAs for the treatment of L. monocytogenes infection. Furthermore, ARI scores ≤ 0.2 for EPAs were observed in polony, potato chips, muffins, and assorted sandwiches, whereas ARI scores for non-PAs were >0.2 across all the RTE food types. The ARI-based estimate identified potential risks associated with some RTE foods, including fried fish, red Vienna sausage, Russian sausage, fruit salad, bread, meat pies, fried chicken, cupcakes, and vetkoek. This investigation identified a high risk of EMPT due to the presence of antimicrobial-resistant L. monocytogenes in RTE foods, which could result in severe health consequences.

Seasonal variations and associated health risks of polychlorinated naphthalenes in Markman Canal, Eastern Cape Province, South Africa.

This study focused on evaluation of the levels, seasonal variations and human health risks associated with polychlorinated naphthalenes (PCNs) in water and sediment samples of Markman Canal using solid phase and soxhlet extraction methods respectively, followed by clean-up and quantification with gas chromatograph coupled with microelectron capture detector. The sum of eight PCNs congener's (∑8PCNs) in water and sediments varied from 0.035 to 0.699 µg/L and 0.260 to 6744.16 µg/kg dw, respectively. Highest PCNs concentrations were recorded in water during winter, while sediment samples collected during spring contained maximum levels. The estimated toxic equivalency (TEQ) for water and sediments was 1.19 × 10-7-1.47 × 10-4 µg/L and 4.43 × 10-5-4.19 × 10-1 µg/kg consecutively. The PCN levels and TEQ values revealed that this waterbody is polluted but constitutes no excess health risk. Efforts should be made to control all the activities contributing to pollution of this canal.

The Potential of Antibiotics and Nanomaterial Combinations as Therapeutic Strategies in the Management of Multidrug-Resistant Infections: A Review.

Antibiotic resistance has become a major public health concern around the world. This is exacerbated by the non-discovery of novel drugs, the development of resistance mechanisms in most of the clinical isolates of bacteria, as well as recurring infections, hindering disease treatment efficacy. In vitro data has shown that antibiotic combinations can be effective when microorganisms are resistant to individual drugs. Recently, advances in the direction of combination therapy for the treatment of multidrug-resistant (MDR) bacterial infections have embraced antibiotic combinations and the use of nanoparticles conjugated with antibiotics. Nanoparticles (NPs) can penetrate the cellular membrane of disease-causing organisms and obstruct essential molecular pathways, showing unique antibacterial mechanisms. Combined with the optimal drugs, NPs have established synergy and may assist in regulating the general threat of emergent bacterial resistance. This review comprises a general overview of antibiotic combinations strategies for the treatment of microbial infections. The potential of antibiotic combinations with NPs as new entrants in the antimicrobial therapy domain is discussed.

Assessment of the molecular epidemiology and genetic multiplicity of Listeria monocytogenes recovered from ready-to-eat foods following the South African listeriosis outbreak.

Following the recent listeriosis outbreak in South Africa, this study was carried out to assess the safety level of various common ready-to-eat foods (RTE) obtained from supermarkets and grocery stores in major towns and cities within the Amathole, Chris Hani and Sarah Baartman Districts Municipalities, Eastern Cape Province, South Africa. A sum of 239 food samples was collected from these locations, and Listeria monocytogenes (Lm) was isolated in line with the recommended techniques by the International Organization for Standardization EN ISO 11290:2017 parts 1 and 2. Identification of the pathogen and detection of various associated virulence genes was done using Polymerase Chain Reaction (PCR) techniques. From the RTE food samples processed, Lm was detected in 107 (44.77%) of the samples. Russian sausage was the most contaminated (78.57%), followed by sliced polony (61.90%), muffins (58.33%), polony (52.63%), and pies (52.38%), while all vetkoek samples examined were negative for Lm. Although the prevalence of Lm in the food samples was very high, concentrations were generally < 100 CFU/g. Strains of Lm recovered from the RTE foods were predominantly epidemiological strains belonging to serotypes 1/2a, 1/2b and 4b. The prevalence of 10 virulence genes including the inlA, InlC, inlJ, plcA, hlyA, plcB, prfA, mpl, inlB, and actA were detected among Lm isolates. Most of the isolates (69.07%) demonstrated the potential for biofilm formation and were categorized as weak (14.95%), moderate (13.40%) and strong (40.72) biofilm formers. Furthermore, molecular typing revealed high levels of genetic diversity among Lm isolates. The findings of this investigation suggested that the presence of Lm in the RTE foods may constitute potential threats to the food sector and could pose public health hazards to consumers, particularly the high-risk group of the population. We, therefore, recommend that adequate food monitoring for safety and proper regulation enforcement in the food sector must be ensured to avoid any future listeriosis outbreak that could be linked to RTE foods in South Africa.

Antibacterial Activity of Metallic Nanoparticles against Multidrug-Resistant Pathogens Isolated from Environmental Samples: Nanoparticles/Antibiotic Combination Therapy and Cytotoxicity Study.

Multidrug-resistant organisms have increased the prevalence of infectious diseases and have become the leading source of death globally. The adverse effects associated with conventional antibiotics cannot be underestimated, and as a result, the quest for antibacterial agents has received great attention over the years. Therefore, the current research was designed to synthesize and examine the antibacterial properties of two metallic nanoparticles, silver nanoparticles (AgNPs) and zinc oxide nanoparticles (ZnONPs), as well as their antibiotic combination therapy against multidrug-resistant bacteria. AgNPs and ZnONPs were synthesized by the coprecipitation method and characterized. Thereafter, their antibacterial activity against multidrug-resistant bacteria was investigated using the microdilution technique. Subsequently, the interactions between the synthesized nanoparticles and antibiotics were evaluated by checkerboard assay. Time-kill assays were carried out to assess bacteriostatic or bactericidal effects, and the cytotoxicity study was carried out by MTT assay. The SEM analysis of AgNPs and ZnONPs were spherical with an average size of 21.03 and 43.37 nm, respectively. FTIR analysis showed the characteristics of the metal-oxygen vibrational band for both materials around 450 cm-1, which indicated the successful synthesis of these antibacterial agents. The EDX characterization revealed Zn and O with 77.89% and 18.24% abundance in ZnONPs and Ag with 95.65% abundance in AgNPs. UV-vis absorption spectra of AgNPs was obtained around 400 nm. ZnONPs showed a moderate antibacterial effect against Enterococcus species with a MIC range of 2.5-5 mg/mL, while AgNPs demonstrated a strong antibacterial effect against the tested bacterial strains with a MIC range of 0.078-0.039 mg/mL. The ZnONPs were found to be cytotoxic against Vero cell lines at the tested concentrations, whereas AgNPs had no cytotoxic effect at lower concentrations. Their combination activities showed synergetic and additive effects. These findings revealed that these synthesized materials could serve as alternate antibacterial agents against multidrug-resistant Acinetobacter baumanni and Enterococcus species.

Antibiotic Resistance Profile of Listeria monocytogenes Recovered from Ready-to-Eat Foods Surveyed in South Africa.

ABSTRACT: In recent decades, there has been an increase in the reports of antimicrobial resistance of Listeria monocytogenes, which constitutes a serious threat to the therapeutic management of listeriosis infection. Our study profiled the antibiogram fingerprint of L. monocytogenes isolates (n = 194) recovered from common South African ready-to-eat foods. L. monocytogenes isolates recovered from foods were tested against a panel of 22 antibiotics using the disk diffusion method. Antimicrobial resistance (>50%) against ceftriaxone (53.1%), trimethoprim (56.2%), streptomycin, cefotetan (59.3%), sulfamethoxazole (61.9%), vancomycin, and oxytetracyclines (62.9%) were observed. Thirty of the isolates (15.5%) were resistant against only one or two antibiotics, whereas 162 (83.5%) exhibited phenotypic multiple antibiotic resistance. Only two (1%) of the isolates did not exhibit phenotypic resistance against any antibiotics screened. Multiple antibiotic phenotypes revealed high resistance patterns, and the multiple antibiotic indices were greater than the Krumperman permissible (>0.2) benchmark. Of the 44 genes screened, 22 antimicrobial resistance genes were detected among ready-to-eat food isolates, including resistance determinants that encode sulfonamides (n = 125, 64.4%), ß-lactams (n = 86, 44.3%), phenicols (n = 25, 12.9), and aminoglycosides (n = 93, 47.9%) resistance. We conclude that the presence of resistant L. monocytogenes isolates harboring corresponding antimicrobial resistance genes in foods could compromise safety and constitute severe health consequences if consumed.

Assessment of multidrug-resistant Listeria monocytogenes in milk and milk product and One Health perspective.

The occurrence and the antibiogram signatures of Listeria monocytogenes (Lm) recovered from 65 milk samples and its products within the Eastern Cape province were examined. The EN ISO 11290:2017 procedures Parts 1 and 2 described by the International Organization for Standardization for the enumeration and isolation of Lm was adopted for the study. Lm was detected in 18.46% of all the samples examined, and the strains recovered from the samples belong to serotypes 4b and 1/2b. The virulence determinants including prfA, plcA, plcB, inlA, inlC, hly, mpl, actA, inlJ and inlB were detected in all the isolates. About 95.24% of the studied Lm isolates demonstrated potential capacity for biofilm formation. The antibiogram profile revealed high resistance against sulfamethoxazole (71.43%), trimethoprim (52.86%); erythromycin, cefotetan and oxytetracycline (42.86% respectively). About 85.71% exhibited multiple antibiotic resistance phenotypes against the test antibiotics. The resistance determinants encoding resistance against the ß-lactamase antibiotics [such as the blaTEM, blaSHV, blaTEM variants (TEM-1 and TEM-2) and the blaZ], the tetracycline resistance genes (including tetA, tetD, tetG and tetM and tetK) were detected among resistant isolates. In addition, the aminoglycoside resistance gene aph (3)-IIa (aphA2)a was detected only in one isolate. Finally, the sulfonamide resistance genes including the sul2 and the sul1 genes were the most frequently observed among Lm isolates. Generally, 71.43% of all Lm isolates recovered from the samples investigated harboured one or more resistance genes encoding resistance against various antibiotics. The antibiogram signatures of Lm isolates observed in this study is an indication that empirical treatment of listeriosis may be challenging in the future as the pathogen may obliterate the success of antibiotics. We, therefore, advocate for the recognition of the One Health approach to ensuring food safety and curbing the spread of antimicrobial resistance in food.

Influence of physicochemical parameters on PPCP occurrences in the wetlands.

There have been many global studies on the occurrence and distribution of pharmaceuticals and personal care products (PPCPs) in the aquatic resources, but reports on the effects of physicochemical properties of water on their concentrations are very scarce. The amounts and removal of these contaminants in various environmental media are dependent on these physicochemical properties, which include pH, temperature, electrical conductivity, salinity, turbidity, and dissolved oxygen. Here, we reviewed the influence of these properties on determination of PPCPs. Reports showed that increase in turbidity, electrical conductivity, and salinity gives increase in concentrations of PPCPs. Also, neutral pH gives higher PPCP concentrations, while decrease in temperature and dissolved oxygen gives low concentration of PPCPs. Nevertheless, it is quite challenging to ascertain the influence of water quality parameters on the PPCP concentration, as other factors like climate change, type of water, source of pollution, persistence, and dilution factor may have great influence on the concentration of PPCPs. Therefore, routine monitoring is suggested as most water quality parameters vary because of effects of climate change.

Molecular Characterization and Antibiotic Susceptibility Profile of Acinetobacter baumannii Recovered from Hospital Wastewater Effluents.

Acinetobacter baumannii (A. baumannii) plays a significant part in nosocomial infections world over and is re-emerging as a formidable pathogen due to the wide range of antibiotic resistance factors it acquires and environmental resilience. The high attendance of patients (outpatients and inpatients) into the health care facilities formed the basis for the selection of the hospitals. Consequently, this study profiled the antibiogram and antibiotic resistance genes of A. baumannii isolated from selected hospital wastewater effluents. A total of twenty-four (24) wastewater samples from three selected hospital drainages were collected and analysed presumptively by culture-dependent methods for A. baumannii. The identity confirmation of A. baumannii was done by the amplification of recA and blaoxa-51 genes. Virulence and antibiotic resistance markers were assessed using polymerase chain reaction. A total of 53 A. baumannii isolates were confirmed and the highest antibiotic resistance profile was 93% (piperacillin). Multiple antibiotic resistance index (MARI) showed a range of 0.23 and 0.46. FimH virulence gene was detected in 29 (55%) of the isolates. Tetracycline and beta-lactam resistance markers were found; 70% and 92% of the isolates possessed tetA and ampC genes. The isolates showed high level of resistance to antibiotics. The multiple antibiotic resistance index (MARI) of ≥ 0.2 indicates that some of the isolates harbour virulence and resistance traits emerging from high-risk source thereby projecting a threat to public health.

Analytical Evaluation of Carbamate and Organophosphate Pesticides in Human and Environmental Matrices: A Review.

Pesticides are synthetic compounds that may become environmental contaminants through their use and application. The high productivity achieved in the agricultural industry can be credited to the use and application of pesticides by way of pest and insect control. As much as pesticides have a positive impact on the agricultural industry, some disadvantages come with their application in the environment because they are intentionally toxic, and this is more towards non-target organisms. They are grouped into chlorophenols, organochlorines, synthetic pyrethroid, carbamates, and organophosphorus based on their structure. The symptoms of exposure to carbamate (CM) and organophosphates (OP) are similar, although poisoning from CM is of a shorter duration. The analytical evaluation of carbamate and organophosphate pesticides in human and environmental matrices are reviewed using suitable extraction and analytical methods.

Occurrence and Risk Assessment of Polybrominated Diphenyl Ethers in Surface Water and Sediment of Nahoon River Estuary, South Africa.

The concentrations, potential sources, and compositional profile of PBDEs in the surface water and sediment of Nahoon Estuary, East London, South Africa, were investigated with solid-phase extraction and ultra-sonication, respectively, followed by gas-chromatography-electron capture detection. The seasonal range of the contaminants' concentrations in water and sediment samples in spring season were ∑PBDE 329 ± 48.3 ng/L (25.32-785 ng/L) and ∑PBDE 4.19 ± 0.35 ng/g dw (1.91-6.57 ng/g), but ∑PBDE 62.1 ± 1.50 ng/L (30.1-110 ng/L) and ∑PBDE 65.4 ± 15.9 ng/g dw (1.98-235 ng/g) in summer, respectively. NH1 (first sampling point) was the most contaminated site with PBDE in the Estuary. The potential source of pollution is attributed to the stormwater runoff from a creek emptying directly into the Estuary. This study's dominant PBDE congener is BDE-17, ranging from below detection limit to 247 ng/L and 0.14-32.1 ng/g in water and sediment samples, respectively. Most detected at all the sites were BDE-17, 47, 66, and 100. Most BDE-153 and 183 are found in sediment in agreement with the fact that higher brominated congeners of PBDE adsorb to solid materials. There was no correlation between the congeners and organic carbon and organic matter. However, the human health risk assessment conducted revealed that the PBDE concentration detected in the estuary poses a low eco-toxicological risk. Nevertheless, constant monitoring should be ensured to see that the river remains safe for the users, as it serves as a form of recreation to the public and a catchment to some neighbourhoods.

Spatiotemporal Distribution and Analysis of Organophosphate Flame Retardants in the Environmental Systems: A Review.

In recent times, there has been a cumulative apprehension regarding organophosphate flame retardants (OPFRs) owing to their high manufacturing and usage after brominated flame retardants were strictly regulated and banned from being distributed and used in many countries. OPFRs are known as the main organic pollutants in the terrestrial and aquatic environment. They are very dangerous to humans, plants and animals. They are also carcinogenic and some have been implicated in neurodevelopmental and fertility challenges. OPFRs are distributed into the environment through a number of processes, including the usage, improper disposal and production of materials. The solid phase extraction (SPE) method is suggested for the extraction of OPFRs from water samples since it provides high quality recoveries ranging from 67% to 105% and relative standard deviations (RSDs) below 20%. In the same vein, microwave-assisted extraction (MAE) is highly advocated for the extraction of OPFRs from sediment/soil. Recoveries in the range of 78% to 105% and RSDs ranging from 3% to 8% have been reported. Hence, it is a faster method of extraction for solid samples and only demands a reduced amount of solvent, unlike other methods. The extract of OPFRs from various matrices is then followed by a clean-up of the extract using a silica gel packed column followed by the quantification of compounds by gas chromatography coupled with a mass spectrometer (GC-MS) or a flame ionization detector (GC-FID). In this paper, different analytical methods for the evaluation of OPFRs in different environmental samples are reviewed. The effects and toxicities of these contaminants on humans and other organisms are also discussed.

Incidence and genetic diversity of multi-drug resistant Listeria monocytogenes isolates recovered from fruits and vegetables in the Eastern Cape Province, South Africa.

We investigated the prevalence, genetic diversity and antibiogram profiles of Listeria monocytogenes (Lm) recovered from fruits and vegetables sourced from three District Municipalities in the Eastern Cape Province, South Africa after the recent listeriosis outbreak in the country. The procedure outlined by the International Organization for Standardization EN ISO 11290:2017 Parts 1 and 2 was adopted for the isolation of Lm from 140 vegetable samples. Molecular detection of the pathogen and the presence of 10 virulence-associated markers were assessed. Lm was detected in 42.86% of all the vegetable samples tested. Highest prevalence was recorded in tomato (65.52%) followed by spinach (56.67%), cabbage (38.10%), apple (36.84%), mushroom (29.41%) and carrot (10%). The virulence determinants including the inlA, inlC, prfA and plcA, hly, plcB genes were detected in all Lm isolates whereas, inlJ (88.35%), inlB (86.41%), mpl (92.23%) and actA (84.55%) respectively. High susceptibility (> 50) was observed to all antibiotics tested except for sulfamethoxazole (17.48%), streptomycin (38.84%), amoxicillin (41.75%) and erythromycin (43.69%). However, high resistance against sulfamethoxazole (80.58%), amoxicillin (58.25%) and erythromycin (49.52%) were observed. About 85.44% of Lm isolates showed multidrug-resistance phenotypes against the test antibiotics. Furthermore, twenty (20) resistance genes encoding tetracyclines, sulphonamides, phenicols, aminoglycosides, ß-lactamases, and variants of the extended-spectrum of ß-lactamases (ESBLs) resistance were detected among the Lm isolates. The sul2 (90.81), tetM (68.42%) sul1 (45.98%) were more prevalent among the resistant strains. The dendrogram signatures generating seven clades is an indication of the high genetic diversity among the isolates. We conclude that the presence of Lm in fruits and vegetables is a potential threat to the consumers and a potential public health hazard, particularly to the high-risk group of the population.

Spatial monitoring and health risk assessment of polybrominated diphenyl ethers in environmental matrices from an industrialized impacted canal in South Africa.

This study investigates the pollution of Markman stormwater runoff, which is a tributary to Swartkops River Estuary. Solid-phase and ultrasonic extraction methods were utilized in the extraction of water and sediment samples, respectively. The pH of the sampling sites was above the EU guideline. The ranges of concentration of [Formula: see text]PBDE obtained in water and sediment samples for all the seasons were 58.47-1357 ng/L and 175-408 ng/g, respectively. Results also showed that BDE-66 was the dominant congener, specifically in the industrial zone, where its concentrations ranged from 2 to 407 ng/g in sediment. Consequently, the high concentration of BDE- 66 in the sediment of stormwater calls for concern. Penta-BDE suggests potential moderate eco-toxicological risk, as evident in the calculated risk assessment. The result showed possible photodegradation along the contaminant's travel time, as only 7% of the PBDE was detected at the point of entry into the Swartkops River Estuary. Markman stormwater may be contributing heavily to the pollution load of Swartkops River, as evident in the alarming concentrations of PBDEs obtained. The industries at this zone should eliminate the contaminants before discharging their effluents into the canal.

Spatial and seasonal variations of endocrine disrupting compounds in water and sediment samples of Markman Canal and Swartkops River Estuary, South Africa and their ecological risk assessment.

The presence of pharmaceuticals in surface water and sediment has sparked up a global concern, as they could cause harm to human health. In this study, we investigated five pharmaceuticals (caffeine, carbamazepine, sulfamethoxazole, testosterone, and trimethoprim) in surface water and sediment samples from Swartkops River Estuary and Markman Stormwater Canal, in the Eastern Cape Province, South Africa. Ultra-Performance Liquid Chromatography (UPLC) systems coupled with a hyphenated quadrupole-time-of-flight mass spectrometry (QTOF-MS) was used for the analysis. Of the five pharmaceuticals investigated, three were detected in sediment samples at concentrations ranging from BDL - 23.86 µg/kg (dw). Caffeine and sulfamethoxazole were below the detection limit. The finding of this current study suggests that Markman and Motherwell's stormwater canals were potential contributors to pollution in Swartkops River Estuary. Ecotoxicity risk assessment indicated that trimethoprim and carbamazepine could constitute potential risk to aquatic organisms in Markman Canal and Swartkops Estuary, suggesting the need for proper control measure to prevent the pollution from toxicants in aquatic resources.

Antibiogram Profile of Acinetobacterbaumannii Recovered from Selected Freshwater Resources in the Eastern Cape Province, South Africa.

Acinetobacter species have been found in a variety of environments, including soil, food, plants, hospital environments and water. Acinetobacter baumannii is an opportunistic and emerging waterborne pathogen. It has been implicated in several nosocomial infections that demonstrate resistance to commonly administered antibiotics. We investigated phenotypic antibiotic resistance (PAR) and relevant antibiotic resistance genes (ARGs) in A. baumannii isolated from three freshwater resources in the Eastern Cape Province, South Africa; A. baumannii (410) was confirmed by the recA and gyrB genes of 844 suspected Acinetobacter species in the water samples. The PAR of the confirmed isolates was assessed using a panel of 11 antibiotics by the disc diffusion method, while ARGs were investigated in isolates exhibiting PAR. The A. baumannii isolates were resistant to piperacillin-tazobactam (11.2%), ceftazidime (12%), cefotaxime (18.8%), cefepime (8.8%), imipenem (2.7%), meropenem (4.15%), amikacin (2.4%), gentamicin (8.8%), tetracycline (16.8%), ciprofloxacin (11%) and trimethoprim/sulfamethoxazole (20.5%). For multidrug resistance (MDR), two isolates were resistant to all antibiotics and 28 isolates were resistant to imipenem and meropenem. Moreover, ß-lactamases blaTEM (64.4%) and blaOXA-51 (28.70%) as well as sulphonamides sul1 (37.1%) and sul2 (49.4%) were common ARGs. Overall, PAR and ARGs had positive correlations (r) in all rivers. Detection of MDR-A. baumannii in freshwater resources could be linked to possible wastewater discharge from the nearby animal farms, indicating potential implications for public health.

Distribution and molecular characterization of ESBL, pAmpC ß-lactamases, and non-ß-lactam encoding genes in Enterobacteriaceae isolated from hospital wastewater in Eastern Cape Province, South Africa.

Globally, there is an increasing occurrence of multidrug-resistant (MDR) Enterobacteriaceae with extended-spectrum ß-lactamases (ESBLs) and/or plasmid-encoded AmpC (pAmpC) ß-lactamases in clinical and environmental settings of significant concern. Therefore, we aimed to evaluate the occurrence of ESBL/pAmpC genetic determinants, and some essential non-ß-lactam genetic determinants in the MDR phenotypic antimicrobial resistance in Enterobacteriaceae isolates recovered from hospital wastewater. We collected samples from two hospitals in Amathole and Chris Hani District Municipalities in the Eastern Cape Province, South Africa, within October and November 2017. Using the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF), we identified a total of 44 presumptive Enterobacteriaceae isolates. From this, 31 were identified as the targeted Enterobacteriaceae members. Thirty-six percent of these belonged to Klebsiella oxytoca, while 29% were Klebsiella pneumoniae. The other identified isolates included Citrobacter freundii and Escherichia coli (10%), Enterobacter asburiae (6%), Enterobacter amnigenus, Enterobacter hormaechei, and Enterobacter kobei (3%). We established the antibiotic susceptibility profiles of these identified bacterial isolates against a panel of 18 selected antibiotics belonging to 11 classes were established following established guidelines by the Clinical and Laboratory Standard Institute. All the bacterial species exhibited resistance phenotypically against at least four antibiotic classes and were classified as MDR. Notably, all the bacterial species displayed resistance against cefotaxime, ampicillin, nalidixic acid, and trimethoprim-sulfamethoxazole. The generated multiple antibiotic resistance indices ranged between 0.5 to 1.0, with the highest value seen in one K. oxytoca isolated. Molecular characterization via the Polymerase Chain Reaction uncovered various ESBLs, pAmpCs, and other non-ß-lactam encoding genes. Of the phenotypically resistant isolates screened for each class of antibiotics, the ESBLs detected were blaCTX-M group (including groups 1, 2, and 9) [51.6% (16/31)], blaTEM [32.3% (10/31)], blaOXA-1-like [19.4% (6/31)], blaSHV [12.9% (4/31)], blaPER [6.5% (2/31)], blaVEB [3.2% (1/31)], blaOXA-48-like and blaVIM [15.4% (2/13)], and blaIMP [7.7% (1/13)]. The pAmpC resistance determinants detected were blaCIT [12.9% (4/31)], blaFOX [9.7% (3/31)], blaEBC [6.5% (2/31)], and blaDHA [3.2% (1/31)]. The frequencies of the non-ß-lactam genes detected were catII [79.2% (19/24)], tetA [46.7% (14/30)], sulI and sulII [35.5% (11/31)], tetB [23.3% (7/30)], aadA [12.9% (4/31)], tetC [10% (3/30)], and tetD [3.3% (1/30)]. These results indicate that hospital wastewater is laden with potentially pathogenic MDR Enterobacteriaceae with various antibiotic resistance genes that can be spread to humans throughout the food chain, provided the wastewaters are not properly treated before eventual discharge into the environment.