Mechanism of action of secondary metabolites from marine-derived Streptoymces on bacterial isolates by membrane permeability.

This study was designed to further investigate the potential mechanism of action of our previously characterized and identified marine-derived Streptomyces extracts (ESC003 and ESC012) on selected bacterial isolates from our culture bank. Time-kill kinetics, protein and lipid leakages assay, cell membrane permeability, phosphate and potassium ions efflux assay, extracellular adenosine triphosphate (ATP) concentration and membrane potential (MP) were all carried out using the marine-derived Streptomyces extract to determine and understand the probable mode of action at which the extract inhibit or kill bacterial cell. The MIC of ESC003 and ESC012 ranged from 0.16 to 6.25 mg/mL while the MBC ranged from 1.25 to >10 mg/mL. On the time-kill kinetics, a reduction in mean viable cell amount was detected at respective time studied. For the impermeability of the bacterial isolates, the relative electric conductivity increased with increase in concentration and time interval of exposure. As regards the protein leakage, lipid leakage, 260 nm absorbing materials leakage, phosphate and potassium ions efflux; considerable amount of these products were leaked with increase in concentration and time of exposure to the bacterial isolates. The extracellular ATP concentration from respective bacterial isolates increased appreciably with increased concentration of exposure with a simultaneous decrease in membrane potential. Findings from this study revealed that the Streptomyces extracts revealed a significant breakthrough against susceptible bacterial isolates via the permeability of the bacterial cell membrane, and thus resulted in the outflow of ATP, electrolytes, DNA materials, and proteins. These changes lead to disruption, and eventually cell death, which were proportional to a concurrent decrease in the viability of the bacterial cell.

Microarray-based detection of resistance genes in coagulase-negative staphylococci isolated from cattle and buffalo with mastitis in Egypt.

The present study aimed to provide a detailed characterization of coagulase-negative staphylococci (CoNS) isolated from cows and buffaloes with mastitis. The study included seventy-five CoNS isolates (60 came from cattle and 15 from buffaloes) originating from 68 individual quarters of 67 dairy cows (53 cattle and 14 buffaloes). The animals belonged to five different small holding dairy herds (n = 140 cows) that show clinical or subclinical mastitis. CoNS isolates were phenotypically characterized using MALDI-TOF-MS and were further genotypically characterized by microarray-based assays. Furthermore, the antimicrobial susceptibility of CoNS strains which carried the mecA gene was examined by broth microdilution. The occurrence of CoNS in the respective five herds was 10.5%, 14.7%, 14.8%, 12.8%, and 9.9%, with an average of 12.4%. Six different CoNS species were identified: S. sciuri (n = 37; 30 from cattle and 7 from buffaloes), S. chromogenes (n = 14; 8 from cattle and 6 from buffaloes), S. haemolyticus (n = 10; nine from cattle and one buffalo), S. xylosus (n = 10; nine from cattle and one buffalo), S. hyicus (n = 2), S. warneri (n = 1), and unidentified CoNS (n = 1). Twenty percent (20%) of CoNS isolates (17.3% of cattle origin) carried at least one antimicrobial resistance gene, while 4% of the isolate including two isolates of S. haemolyticus and one S. warneri of cattle origin carried the mecA gene and were phenotypically identified as methicillin-resistant strains. The genes detected were blaZ (16%), followed by tet(K) (8%), aacA-aphD (4%), aphA3 (2.6%), msr(A) (2.6%), [far1 (2.6%), and fusC (2.6%)], sat (2.6%), and cat (1.3%) conferring resistance to penicillin, tetracycline, gentamicin, neomycin/kanamycin, erythromycin, fusidic acid, streptothricin, and chloramphenicol, respectively. The majority of investigated CoNS strains displayed considerably low prevalence of resistance genes, while resistance to more than three antibiotics was found in S. haemolyticus and S. warneri. Implementing effective preventive measures is, therefore, important for limiting the transmission of CoNS, rather than using antibiotics to control mastitis in bovines.

Antibiotics resistance and toxin profiles of Bacillus cereus-group isolates from fresh vegetables from German retail markets.

BACKGROUND: This study aimed to evaluate the safety of raw vegetable products present on the German market regarding toxin-producing Bacillus cereus sensu lato (s.l.) group bacteria. RESULTS: A total of 147 B. cereus s.l. group strains isolated from cucumbers, carrots, herbs, salad leaves and ready-to-eat mixed salad leaves were analyzed. Their toxinogenic potential was assessed by multiplex PCR targeting the hemolysin BL (hbl) component D (hblD), non-hemolytic enterotoxin (nhe) component A (nheA), cytotoxin K-2 (cytK-2) and the cereulide (ces) toxin genes. In addition, a serological test was used to detect Hbl and Nhe toxins. On the basis of PCR and serological results, none of the strains were positive for the cereulide protein/genes, while 91.2, 83.0 and 37.4% were positive for the Hbl, Nhe and CytK toxins or their genes, respectively. Numerous strains produced multiple toxins. Generally, strains showed resistance against the ß-lactam antibiotics such as penicillin G and cefotaxim (100%), as well as amoxicillin/clavulanic acid combination and ampicillin (99.3%). Most strains were susceptible to ciprofloxacin (99.3%), chloramphenicol (98.6%), amikacin (98.0%), imipenem (93.9%), erythromycin (91.8%), gentamicin (88.4%), tetracycline (76.2%) and trimethoprim/sulfamethoxazole combination (52.4%). The genomes of eight selected strains were sequenced. The toxin gene profiles detected by PCR and serological test mostly agreed with those from whole-genome sequence data. CONCLUSIONS: Our study showed that B. cereus s.l. strains encoding toxin genes occur in products sold on the German market and that these may pose a health risk to the consumer if present at elevated levels. Furthermore, a small percentage of these strains harbor antibiotic resistance genes. The presence of these bacteria in fresh produce should, therefore, be monitored to guarantee their safety.

Characterization of extracellular virulence properties and biofilm-formation capacity of Vibrio species recovered from ready-to-eat (RTE) shrimps.

In this study, we evaluated the virulence factor production, biofilm-forming ability and cell surface properties of ready-to-eat shrimps associated vibrios strains. A total of 1440 ready-to-eat (RTE) shrimp samples were purchased from open markets in southern Nigeria, from November 2016 to October 2017. Biofilm formation was carried out using the microtitre plate method. Cell-to-cell adhesion of Vibrio species was assessed via surface hydrophobicity using the bacterial adherence to hydrocarbons (BATH) and salting aggregation technique, autoaggregation and coaggregation assay. The virulence potential of the identified 120 Vibrio strains includes haemolysis 107 (89.17%), lipase 106 (88.33%), protease 108 (90%), gelatinase 111 (92.5%), the presence of surface-layer (S-layer) 109 (90.8%) and DNA degrading activity 107 (89.17%). Biofilm formation at 30 °C tryptone soy broth in dynamic conditions revealed total biofilm producers for the Vibrio species as follows: V. parahaemolyticus (95.65%), V. vulnificus (92.86%), V. fluvialis (91.67%), V. alginolyticus (87.5%), V. cholerae (100%), V. mimicus (90%), V. harveyi (66.7%), and other Vibrio spp. (84%). A total of 50 biofilm producing vibrios using BATH technique include 49 (98%) hydrophilic and 1 (2%) moderately hydrophobic. Using the modified salting aggregation technique, 50 (100%) was characterized as hydrophilic. Autoaggregation index for the 12 biofilms producing Vibrio strains ranged from 11.6 to 41.3%, while the autoaggregation index for the 12 test bacteria ranged from 26.2 to 71.3%. Coaggregation between the 12 test bacteria with the 12 Vibrio strains ranged from 9.3 to 78.5%. However most vibrios in this study were hydrophilic, their hydrophilic potential is important for their capability to autoaggregate and coaggregate. Findings on the specific process by which virulent Vibrio spp. form biofilm and adhere to shrimp surface as attached plankton may assist in monitoring epidemics of the pathogen.

Assessment of water quality of rivers that serve as water sources for drinking and domestic functions in rural and pre-urban communities in Edo North, Nigeria.

Surface waters are important to humans because they are a significant water supply source. They are, however, under serious environmental stress and are being threatened as a consequence of developmental activities. The present study describes the physicochemical properties and water quality indices of five different rivers used for drinking and other domestic activities in rural and pre-urban communities in Edo North, Nigeria. The physicochemical variable ranges include pH [wet season (6.47 ± 0.30-6.89 ± 0.11), dry season (6.61 ± 0.14-7.84 ± 0.24)], electrical conductivity (EC) [wet season (3.33 ± 0.57-12.33 ± 2.51 µS/cm), dry season (5.33 ± 0.57-21.33 ± 2.08 µS/cm)], water temperature [wet season (24.23 ± 0.98-25.40 ± 1.15 °C), dry season (26.20 ± 0.55-27.10 ± 0.75 °C)], TDS [wet season (417.00 ± 15.87-433.33 ± 18.50 mg/L), dry season (319.33 ± 16.50-372.66 ± 22.30 mg/L)], turbidity [wet season (1.01 ± 0.11-2.08 ± 0.99 NTU), dry season (3.11 ± 0.01-5.41 ± 0.24 NTU)], and DO [wet season (2.65 ± 0.37-3.99 ± 0.01 mg/L), dry season (2.12 ± 0.11-2.44 ± 0.01 mg/L)]. For the wet and dry seasons, the water quality indices were 120.225 and 585.015 for River Osolo, 119.849 and 445.751 for River Foreign, 200.474 and 587.833 for Ijoh River, 105.261 and 512.498 for Ole River, and 150.114 and 489.992 for Ole Extension River, respectively. The pH was negatively correlated with DO (r = -0.648), and EC was negatively correlated with DO (r = -0.635). Most of the evaluated parameters were within recommended water safety guidelines. However, the water quality index shows that the water quality was very poor and/or unsuitable for drinking and other domestic uses, especially during the dry season. It is suggested that river water be treated prior to its use for drinking and other domestic purposes.

Pathogenic potentials of Aeromonas species isolated from aquaculture and abattoir environments.

The present study elucidated the presence of antibiotics resistance, virulence genes and biofilm potentials among Aeromonas species isolated from abattoir and aquaculture environments in Benin City, Nigeria. A total of 144 wastewater samples were obtained from two independent aquaculture and abattoir environments between May and October 2016. Aeromonas species were isolated on Glutamate Starch Phenol Red (GSP) agar and confirmed using API 20NE kits. Antimicrobial susceptibility profile of the isolates was carried out using standard disc diffusion assay while biofilm potentials were detected by the microtitre plate method and PCR technique was used to detect antibiotics resistance and virulence gene markers. Overall, 32 and 26 Aeromonas species were isolated from the abattoir and aquaculture environments respectively. Isolates from both environments were completely resistant (100%) to penicillin G, ertapenem and tetracycline; whereas aquaculture isolates exhibited absolute sensitivity (100%) towards cefepime. All the virulence gene markers (aerA, hlyA, alt, ast, laf, ascF-G, fla, lip, stx1, and stx2) investigated in this study (except laf) were detected in isolates from both environments. The laf genes were only detected in isolates from abattoir environments. Antibiotics resistant genes including pse, blaTEM and class 1 integron were detected in isolates from both environments. Majority of the isolates (53/58 91.4%) from both environments; demonstrated capacity for biofilm potential. The detection of antibiotic resistance and virulence gene markers as well as biofilm forming ability in Aeromonas species isolated from aquaculture and abattoir environments raise serious public health concern worthy of further investigation.

Multi-antibiotic resistant and putative virulence gene signatures in Enterococcus species isolated from pig farms environment.

The continuous misuse of antimicrobials in food animals both orally and subcutaneously as therapeutic and prophylactic agents to bacterial infections could be detrimental and contribute to the dissemination of resistant clones in livestock production. The present study was carried out to determine the antibiogram and virulence gene characteristics of Enterococcus species from pig farms. A total of 300 faecal samples were obtained from two pig farms in Benin City between February and July 2016. Standard culture-based and polymerase chain reaction (PCR) assay were adopted in the detection and characterization of the Enterococcus species. Antimicrobial susceptibility profile was determined using disc diffusion method. A total of 268 enterococci isolates were recovered from both farms investigated. In Farm A, 94/95 (99%) of E. faecalis isolates were resistant to clindamycin; while 23/25 (92%) of E. faecium isolates were resistant to clindamycin. In farm B, all E. faecalis isolates 119/119 (100%) were resistant to clindamycin; while 26/29 (90%) of E. faecium isolates were resistant to clindamycin. Virulence gene detected in the enterococci isolates includes aggregation (asa1) [Farm A (E. faecalis 66%, E. faecium 76%), Farm B (E. faecalis 71%, E. faecium 13%)] and others. Multidrug resistant profile of the isolates revealed that 17/95 (18%) of E. faecalis and 3/25 (12%) of E. faecium isolates from Farm A as well as, 16/119 (14%) of E. faecalis and 5/29 (17%) of E. faecium isolates from Farm B were resistant to CLIR, PENR, ERYR, GENR, TETR, MEMR, KANR, and PTZR. The high level of resistance observed in the study and their virulence gene signatures, calls for effective environmental monitoring to circumvent the environmental dissemination of resistant pathogenic clones. Thus environmental hygiene should be provided to food animals to prevent the proliferation and spread of resistant bacteria.

Biotreatment of effluent from 'Adire' textile factories in Ibadan, Nigeria.

In this present study, bacteria were isolated from wastewater and polluted soil collected from two cottage textile factories in Ibadan. These bacteria isolates were used for the biotreatment of textile mill effluent. The physicochemical parameters of the textile mill effluent before treatment were carried out and percentage decolourisation of the effluent was analysed using ultraviolet-visible spectroscopy (UV-vis technique). The degradation products of the textile mill effluent characterised by Fourier transform infrared spectroscopy (FTIR). The pH values of the effluent were within the permissible limit of Federal Environmental Protection Agency (FEPA) and National Environmental Standards and Regulations Enforcement Agency (NESREA), while temperature and electric conductivity of the effluents were below the permissible limit of FEPA and NESREA. The BOD, COD, TSS, TDS and chloride of the textile mill effluent from the two cottage textile factories were above the permissible limits of FEPA and NESREA. Twelve bacteria isolates were screened, effective in decolourising commercial dyes and used to decolourise the textile mill effluent. The bacteria isolates were characterised and identified as Bacillus sp., Micrococcus sp., Erwinia sp., Acinetobacter sp. and Nocardia sp. The decolourisation of textile effluent was observed through the changes of spectra of UV-visible spectrophotometer. The following bacteria revealed different percentage proportion of decolouration profile:- Bacillus sp., had the highest percentage decolourisation of 57.7%, whereas Micrococcus sp. and Acinetobacter sp. had percentage decolourisation of 32.8 and 26.3%, respectively. The degradation profile of textile effluent was revealed through FTIR spectral analysis. The changes in the position of major peaks revealed from the textile effluent through FTIR spectral analysis, appearances of new peaks and the disappearances of existing peaks signify the degradation of the wastewater. Thus, some native microorganisms from the textile effluent could be enhanced to effectively degrade effluent from such environments.

Effect of cassava mill effluent on biological activity of soil microbial community.

This study assessed the effect of cassava effluent on soil microbiological characteristics and enzymatic activities were investigated in soil samples. Soil properties and heavy metal concentrations were evaluated using standard soil analytical and spectroscopic methods, respectively. The microbiological parameters measured include microbial biomass carbon, basal soil respiration, catalase, urease, dehydrogenase activities and number of culturable aerobic bacteria, fungi and actinomycetes. The pH and temperature regime vary significantly (p < 0.05) throughout the study period. All other physicochemical parameters studied were significantly different (p < 0.05) higher than the control site. Soil organic carbon content gave significant positive correlations with microbial biomass carbon, basal soil respiration, catalase activity and dehydrogenase activity (r = 0.450, 0.461, 0.574 and 0.591 at p < 0.01), respectively. The quantitative analysis of soil microbial density demonstrates a marked decrease in total culturable numbers of the different microbial groups of the polluted soil samples. Soil contamination decreased catalase, urease and dehydrogenase activities. The findings revealed that soil enzymes can be used as indices of soil contamination and bio-indicator of soil quality.

Draft genome sequences of a blaCTX-M-15-harboring and an atypical enteropathogenic Escherichia coli isolate recovered from slaughterhouses in Nigeria.

We present the draft genome sequences of two Escherichia coli strains isolated from slaughterhouses in Edo State, Nigeria, in 2019. The isolates were identified as blaCTX-M-15-harboring (19-47-58) and atypical enteropathogenic E. coli (aEPEC) (19-47-66), belonging to multilocus sequence types (MLST) ST46 and ST2089, respectively.

Characterization of resistance and virulence factors in livestock-associated methicillin-resistant Staphylococcus aureus.

The study investigated the economic concerns associated with livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in livestock (cow), examining its connection to severe infections, antimicrobial resistance (AMR), and virulence factors. The research, conducted in Edo State, Nigeria, analyzed 400 samples (200 rectal and 200 nasal swabs) collected between March 2018 and February 2019. MRSA prevalence was identified using conventional culture-based methods and polymerase chain reaction (PCR) techniques, revealing 63.5% (n = 254) for Staphylococcus aureus and 55% (n = 220) for MRSA. Of the 76 mecA-positive MRSA isolates, 64.5% (n = 49) exhibited multidrug resistance (MDR) while the remaining were sensitive to specific antimicrobials. Key virulence genes, such as PVL (81.6%; n = 62) and tsst-1 (44.7%; n = 34), were prevalent, along with AMR genes like mecC, tetM, ermA, ermC, vanA, and vanC. Staphylococcal chromosomal cassette mec (SCCmec) typing identified different types, notably II, IVa, and IVb. Biofilm formation, a crucial virulence factor varied in strength, is associated with icaA and icaB genes (p < 0.01). The findings highlighted substantial AMR and biofilm-forming capacity within LA-MRSA isolates, emphasizing the importance of ongoing surveillance for informed treatment strategies, AMR policies, and control measures against MDR staphylococcal infections.

Toxicological profile of chlorophenols and their derivatives in the environment: the public health perspective.

Chlorophenol compounds and their derivatives are ubiquitous contaminants in the environment. These compounds are used as intermediates in manufacturing agricultural chemicals, pharmaceuticals, biocides, and dyes. Chlorophenols gets into the environment from a variety of sources such as industrial waste, pesticides, and insecticides, or by degradation of complex chlorinated hydrocarbons. Thermal and chemical degradation of chlorophenols leads to the formation of harmful substances which constitute public health problems. These compounds may cause histopathological alterations, genotoxicity, mutagenicity, and carcinogenicity amongst other abnormalities in humans and animals. Furthermore, the recalcitrant nature of chlorophenolic compounds to degradation constitutes an environmental nuisance, and a good understanding of the fate and transport of these compounds and their derivatives is needed for a clearer view of the associated risks and mechanisms of pathogenicity to humans and animals. This review looks at chlorophenols and their derivatives, explores current research on their effects on public health, and proffers measures for mitigation.

Effects of biochemical alteration in animal model after short-term exposure of Jatropha curcas (Linn) leaf extract.

This study aims to evaluate potential toxic effect of Jatropha curcas leaves methanol extract on laboratory rats as well as determine its LD50. A total of 80 male Wistar rats were used as the experimental animals, 40 for LD50 determination and the other 40 for toxicity study. Based on the pretest that was done in order to establish a range of toxicity, 4 dosages (86.00, 58.00, 46.00, and 34.0 kg/body weight) were chosen. The rats were randomly assigned into four groups with 10 rats in each group. Rats in groups 1, 2, 3, and 4 were given 0 mg/kg, 500 mg/kg, 1000 mg/kg, and 2000 mg/kg body weight of Jatropha curcas extract, respectively, by oral intubation for 21 days. Thereafter, clinical signs, change in body weight, toxicity symptoms, and biochemical parameters were obtained. The LD50 at 95% confidence limits for rats was 46.0 mg/kg body weight (44.95-52.69 mg/kg body mass). There was no clinical and biochemical signs of toxicity when the extract was administered at 500, 1000, and 2000 mg/kg body weight, respectively (P > 0.05). Results obtained from this study suggest that liver, kidney, and haematological system of rats tolerated methanolic leave extract of Jatropha curcas at a certain concentration.

Surveillance of Vibrio parahaemolyticus pathogens recovered from ready-to-eat foods.

This study examined the occurrence of V. parahaemolyticus from ready-to-eat (RTE) food in Delta State, Nigeria. It also characterized antibiotic resistance and virulence gene profile patterns to determine the associated health risk hazard. Food samples total of 380 were collected randomly and assessed for V. parahaemolyticus. V. parahaemolyticus isolates were characterized for their virulence and antibiogram potentials using a phenotypic and polymerase chain reaction (PCR) approach. A total of 42 (11.1%) samples were contaminated with V. parahaemolyticus. In 17/42 (40.5%) of the V. parahaemolyticus-positive samples, the densities were < 10 MPN/g. However, 19/42 (45.2%) and 6/42 (14.3%) of the samples had densities of 10 - 102 and > 102 MPN/g, respectively. A total of 67 V. parahaemolyticus isolates were identified using PCR; 54(80.6%) isolates were multidrug resistant. A total of 22 (32.8%), 39 (58.2%), and 67 (100%) of the V. parahaemolyticus harbored the tdh, trh, and tlh toxin genes, respectively. The T3SS1 gene (vcrD1) was detected in 67 (100%) of the isolates. The T3SS2α genes which were vcrD2, vopB2, and vopT were detected in 21 (31.3%), 11 (16.4%) and 30 (44.8%) of the isolates respectively. Some of the V. parahaemolytics strains harbored the orf8 gene 20 (29.9%), and a combination of orf8 + tdh genes 12 (17.9%), categorized as pandemic strains. The antibiotic resistance genes detected in this study include blaTEM 33 (49.3), tetM 19 (28.4), cmlA 32(47.8) and sul1 14 (20.9). The concentration levels and prevalence of V. parahaemolyticus in RTE foods indicate contamination of ready-to-eat foods, particularly street foods consumed in the Delta State of Nigeria, threatening public health and consumer safety.

Using machine learning models to predict the effects of seasonal fluxes on Plesiomonas shigelloides population density.

Seasonal variations (SVs) affect the population density (PD), fate, and fitness of pathogens in environmental water resources and the public health impacts. Therefore, this study is aimed at applying machine learning intelligence (MLI) to predict the impacts of SVs on P. shigelloides population density (PDP) in the aquatic milieu. Physicochemical events (PEs) and PDP from three rivers acquired via standard microbiological and instrumental techniques across seasons were fitted to MLI algorithms (linear regression (LR), multiple linear regression (MR), random forest (RF), gradient boosted machine (GBM), neural network (NN), K-nearest neighbour (KNN), boosted regression tree (BRT), extreme gradient boosting (XGB) regression, support vector regression (SVR), decision tree regression (DTR), M5 pruned regression (M5P), artificial neural network (ANN) regression (with one 10-node hidden layer (ANN10), two 6- and 4-node hidden layers (ANN64), and two 5- and 5-node hidden layers (ANN55)), and elastic net regression (ENR)) to assess the implications of the SVs of PEs on aquatic PDP. The results showed that SVs significantly influenced PDP and PEs in the water (p < 0.0001), exhibiting a site-specific pattern. While MLI algorithms predicted PDP with differing absolute flux magnitudes for the contributing variables, DTR predicted the highest PDP value of 1.707 log unit, followed by XGB (1.637 log unit), but XGB (mean-squared-error (MSE) = 0.0025; root-mean-squared-error (RMSE) = 0.0501; R2 =0.998; medium absolute deviation (MAD) = 0.0275) outperformed other models in terms of regression metrics. Temperature and total suspended solids (TSS) ranked first and second as significant factors in predicting PDP in 53.3% (8/15) and 40% (6/15), respectively, of the models, based on the RMSE loss after permutations. Additionally, season ranked third among the 7 models, and turbidity (TBS) ranked fourth at 26.7% (4/15), as the primary significant factor for predicting PDP in the aquatic milieu. The results of this investigation demonstrated that MLI predictive modelling techniques can promisingly be exploited to complement the repetitive laboratory-based monitoring of PDP and other pathogens, especially in low-resource settings, in response to seasonal fluxes and can provide insights into the potential public health risks of emerging pathogens and TSS pollution (e.g., nanoparticles and micro- and nanoplastics) in the aquatic milieu. The model outputs provide low-cost and effective early warning information to assist watershed managers and fish farmers in making appropriate decisions about water resource protection, aquaculture management, and sustainable public health protection.

Polymyxin sensitivity/resistance cosmopolitan status, epidemiology and prevalence among O1/O139 and non-O1/non-O139 Vibrio cholerae: A meta-analysis.

Resistance/sensitivity to polymyxin-B (PB) antibiotic has been employed as one among other epidemiologically relevant biotyping-scheme for Vibrio cholerae into Classical/El Tor biotypes. However, recent studies have revealed some pitfalls bordering on PB-sensitivity/resistance (PBR/S) necessitating study. Current study assesses the PBR/S cosmopolitan prevalence, epidemiology/distribution among O1/O139 and nonO1/nonO139 V. cholerae strains. Relevant databases (Web of Science, Scopus and PubMed) were searched to retrieve data from environmental and clinical samples employing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Random-effect-model (REM) and common-effect-model (CEM) of meta-analysis was performed to determine prevalence of PBR/S V. cholerae strains, describe the cosmopolitan epidemiological potentials and biotype relevance. Heterogeneity was determined by meta-regression and subgroup analyses. The pooled analyzed isolates from articles (7290), with sensitive and resistance are 2219 (30.44%) and 5028 (69.56%). Among these PB-sensitive strains, more than 1944 (26.67%) were O1 strains, 132 (1.81%) were nonO1 strains while mis-reported Classical biotype were 2080 (28.53) respectively indicating potential spread of variant/dual biotype. A significant PB-resistance was observed in the models (CEM = 0.66, 95% CI [0.65; 0.68], p-value = 0.001; REM = 0.83 [0.74; 0.90], p = 0.001) as both models had a high level of heterogeneity (I2 = 98.0%; df=332=1755.09,Qp=2.4932). Egger test (z = 5.4017, p < 0.0001) reveal publication bias by funnel plot asymmetry. The subgroup analysis for continents (Asia, Africa) and sources (acute diarrhea) revealed (98% CI (0.73; 0.93); 55% CI (0.20; 0.86)), and 92% CI (0.67; 0.98). The Epidemiological prevalence for El tor/variant/dual biotype showed 88% CI (0.78; 0.94) with O1 strains at 88% CI (0.78; 0.94). Such global prevalence, distribution/spread of phenotypes/genotypes necessitates updating the decades-long biotype classification scheme. An antibiotic stewardship in the post antibiotic era is suggestive/recommended. Also, there is need for holistic monitoring/evaluation of clinical/epidemiological relevance of the disseminating strains in endemic localities.

Machine learning-guided determination of Acinetobacter density in waterbodies receiving municipal and hospital wastewater effluents.

A smart artificial intelligent system (SAIS) for Acinetobacter density (AD) enumeration in waterbodies represents an invaluable strategy for avoidance of repetitive, laborious, and time-consuming routines associated with its determination. This study aimed to predict AD in waterbodies using machine learning (ML). AD and physicochemical variables (PVs) data from three rivers monitored via standard protocols in a year-long study were fitted to 18 ML algorithms. The models' performance was assayed using regression metrics. The average pH, EC, TDS, salinity, temperature, TSS, TBS, DO, BOD, and AD was 7.76 ± 0.02, 218.66 ± 4.76 µS/cm, 110.53 ± 2.36 mg/L, 0.10 ± 0.00 PSU, 17.29 ± 0.21 °C, 80.17 ± 5.09 mg/L, 87.51 ± 5.41 NTU, 8.82 ± 0.04 mg/L, 4.00 ± 0.10 mg/L, and 3.19 ± 0.03 log CFU/100 mL respectively. While the contributions of PVs differed in values, AD predicted value by XGB [3.1792 (1.1040-4.5828)] and Cubist [3.1736 (1.1012-4.5300)] outshined other algorithms. Also, XGB (MSE = 0.0059, RMSE = 0.0770; R2 = 0.9912; MAD = 0.0440) and Cubist (MSE = 0.0117, RMSE = 0.1081, R2 = 0.9827; MAD = 0.0437) ranked first and second respectively, in predicting AD. Temperature was the most important feature in predicting AD and ranked first by 10/18 ML-algorithms accounting for 43.00-83.30% mean dropout RMSE loss after 1000 permutations. The two models' partial dependence and residual diagnostics sensitivity revealed their efficient AD prognosticating accuracies in waterbodies. In conclusion, a fully developed XGB/Cubist/XGB-Cubist ensemble/web SAIS app for AD monitoring in waterbodies could be deployed to shorten turnaround time in deciding microbiological quality of waterbodies for irrigation and other purposes.

Multidrug-resistant extended spectrum ß-lactamase (ESBL)-producing Escherichia coli from farm produce and agricultural environments in Edo State, Nigeria.

Antimicrobial resistance (AMR) is a major public health concern, especially the extended-spectrum ß-lactamase-producing (ESBL) Escherichia coli bacteria are emerging as a global human health hazard. This study characterized extended-spectrum ß-lactamase Escherichia coli (ESBL-E. coli) isolates from farm sources and open markets in Edo State, Nigeria. A total of 254 samples were obtained in Edo State and included representatives from agricultural farms (soil, manure, irrigation water) and vegetables from open markets, which included ready-to-eat (RTE) salads and vegetables which could potentially be consumed uncooked. Samples were culturally tested for the ESBL phenotype using ESBL selective media, and isolates were further identified and characterized via polymerase chain reaction (PCR) for ß-lactamase and other antibiotic resistance determinants. ESBL E. coli strains isolated from agricultural farms included 68% (17/25) from the soil, 84% (21/25) from manure and 28% (7/25) from irrigation water and 24.4% (19/78) from vegetables. ESBL E. coli were also isolated from RTE salads at 20% (12/60) and vegetables obtained from vendors and open markets at 36.6% (15/41). A total of 64 E. coli isolates were identified using PCR. Upon further characterization, 85.9% (55/64) of the isolates were resistant to ≥ 3 and ≤ 7 antimicrobial classes, which allows for characterizing these as being multidrug-resistant. The MDR isolates from this study harboured ≥1 and ≤5 AMR determinants. The MDR isolates also harboured ≥1 and ≤3 beta-lactamase genes. Findings from this study showed that fresh vegetables and salads could be contaminated with ESBL-E. coli, particularly fresh produce from farms that use untreated water for irrigation. Appropriate measures, including improving irrigation water quality and agricultural practices, need to be implemented, and global regulatory guiding principles are crucial to ensure public health and consumer safety.

Identification and characterization of MDR virulent Salmonella spp isolated from smallholder poultry production environment in Edo and Delta States, Nigeria.

Salmonella is responsible for some foodborne disease cases worldwide. It is mainly transmitted to humans through foods of animal origin through the consumption of poultry products. The increased international trade and the ease of transboundary movement could propel outbreaks of local origin to translate into severe global threats. The present study aimed to characterize Salmonella serovars isolated from poultry farms in Edo and Delta States, Nigeria. A total of 150 samples (faecal, water and feed) were collected from ten poultry farms between January and August 2020 and analyzed for Salmonella characterization using standard bacteriological and molecular methods. Salmonella serovars identified include: Salmonella Enteritidis [n = 17 (39.5%)], Salmonella Typhimurium [n = 13 (30.2%)] and other Salmonella serovars [n = 13 (30.2%)]. All Salmonella serovars were cefotaxime and ampicillin resistant. The presence of the invA gene ranged from 9(69.2%) to 15(88.2%). The spvC gene ranged from 2(14.4%) to 10(58.8%). All Salmonella serovars had sdiA gene. The Salmonella isolates produced some extracellular virulence factors (such as protease, lipase, ß-hemolytic activity, and gelatinase), while 13(30.2%) of the overall isolates formed strong biofilms. In conclusion, the detection of multiple antibiotic-resistant Salmonella serovars in faecal sources, which also exhibited virulence determinants, constituted a public health risk as these faecal samples have the potential as manure in the growing of crops. These pathogens can be transmitted to humans nearby and through poultry products, resulting in difficult-to-treat infections and economic loss.

Prevalence, multiple antibiotic resistance and virulence profile of methicillin-resistant Staphylococcus aureus (MRSA) in retail poultry meat from Edo, Nigeria.

Introduction: Staphylococcus aureus causes staphylococcal food poisoning and several difficult-to-treat infections. The occurrence and dissemination of methicillin-resistance S. aureus (MRSA) in Nigeria is crucial and well documented in hospitals. However, findings on MRSA from meat in the country are yet to be adequately reported. The current study determined the prevalence, virulence profile and antibiogram characteristics of MRSA from a raw chicken product from retail outlets within Edo. Methods: A total of 368 poultry meat samples were assessed for MRSA using a standard culture-based approach and characterized further using a molecular method. The antimicrobial susceptibility profile of the isolates was determined using the disc diffusion method. The biofilm profile of the isolates was assayed via the crystal violet microtitre-plate method. Virulence and antimicrobial resistance genes were screened using polymerase chain reaction via specific primers. Results: Of the samples tested, 110 (29.9%) were positive for MRSA. All the isolates were positive for deoxyribonuclease (DNase), coagulase and beta-hemolysis production. Biofilm profile revealed 27 (24.55%) weak biofilm formers, 18 (16.36%) moderate biofilm formers, and 39 (35.45%) strong biofilm formers. The isolates harboured 2 and ≤17 virulence genes. Enterotoxin gene profiling revealed that 100 (90.9%) isolates harboured one or more genes. Resistance against the tested antibiotics followed the order: tetracycline 64(58.2%), ciprofloxacin 71(64.6%), trimethoprim 71(64.6%) and rifampin 103(93.6%). A total of 89 isolates were multidrug-resistant, while 3 isolates were resistant to all 22 antibiotics tested. The isolates harboured antimicrobial-resistant determinants such as methicillin-resistant gene (mecA), tetracycline resistance genes (tetK, tetL), erythromycin resistance genes (ermA, ermC), trimethoprim resistance gene (dfrK). All the staphylococcal cassette chromosome mec (SCCmec) IVa and SCCmec V positive isolates harboured the Panton-Valentine Leukocidin Gene (PVL). Conclusion: In conclusion, S. aureus was resistant to commonly used antibiotics; a concern to public health concerning the transmission of these pathogens after consuming these highlight the significance of antimicrobial and enterotoxigenic monitoring of S. aureus in food chains.