Characterization and flocculation properties of biopolymeric flocculant (glycosaminoglycan) produced by Cellulomonas sp. Okoh.

AIMS: Bioflocculant production potential of an actinobacteria isolated from a freshwater environment was evaluated and the bioflocculant characterized. METHODS AND RESULTS: 16S rDNA nucleotide sequence and BLAST analysis was used to identify the actinobacteria and fermentation conditions, and nutritional requirements were evaluated for optimal bioflocculant production. Chemical analyses, FTIR, 1H NMR spectrometry and SEM imaging of the purified bioflocculant were carried out. The 16S rDNA nucleotide sequences showed 93% similarities to three Cellulomonas species (strain 794, Cellulomonas flavigena DSM 20109 and Cellulomonas flavigena NCIMB 8073), and the sequences was deposited in GenBank as Cellulomonas sp. Okoh (accession number HQ537132). Bioflocculant was optimally produced at an initial pH 7, incubation temperature 30°C, agitation speed of 160 rpm and an inoculum size of 2% (vol/vol) of cell density 1·5 × 10(8) cfu ml(-1). Glucose (88·09% flocculating activity; yield: 4·04 ± 0·33 g l(-1)), (NH(4))2 NO(3) (82·74% flocculating activity; yield: 4·47 ± 0·55 g l(-1)) and MgCl(2) (90·40% flocculating activity; yield: 4·41 g l(-1)) were the preferred nutritional source. Bioflocculant chemical analyses showed carbohydrate, protein and uronic acids in the proportion of 28·9, 19·3 and 18·7% in CPB and 31·4, 18·7 and 32·1% in PPB, respectively. FTIR and 1H NMR indicated the presence of carboxyl, hydroxyl and amino groups amongst others typical of glycosaminoglycan. SEM imaging revealed horizontal pleats of membranous sheets closely packed. CONCLUSION: Cellulomonas sp. produces bioflocculant predominantly composed of glycosaminoglycan polysaccharides with high flocculation activity. SIGNIFICANCE AND IMPACT OF THE STUDY: High flocculation activity suggests suitability for industrial applications; hence, it may serve to replace the hazardous flocculant used in water treatment.

Modern knowledge-scape possess petite influence on the factual persistence of resistance determinants (ARGs/MGEs): A map and assessment of discharged wastewater and water bodies.

Antibiotic resistance genes (ARGs) and Mobile genetic elements (MGEs) are major global emerging pollutants of the environment and water nexus which various investigators of related studies have reported. Observing ARGs and MGEs in water bodies, wastewater treatment systems, and estuaries is indicative of relevant risk, resistant bacteria/ARGs spread or potential health concern and may result environmental pathogen bloom if appropriate research-based strategies are not implemented to remove these lethal genetic materials. Despite reports and knowledge-based strategies for removal, the challenge yet persists. This study aims to appraise the impact/contribution of related studies and emphasize the necessity for applying combined research-based/practitioners approach in addressing the expanding challenge of ARGs/MGEs in wastewater/waterbodies. The study describes a bibliometric assessment of antibiotic resistance determinants annual scientific publications on the Web of Science, an annual growth rate of related articles, top articles per citations with search topics and content-review analysis to evaluate the methods of removal of ARGs/MGEs. A total of 1301 articles of wastewater treatment systems were retrieved with date range of 1997-2019. A description of the study Annual Growth Rate of 37.82% at R2 of 0.7863 was observed with an increasing article publication and a decreasing total citation rate indicating persistent reports of dispersion on ARGs/MGEs studies in the water bodies and environment. Although there abound extensive studies and reports of ARGs and MGEs in water nexus and wastewater release with research based removal strategies, the impact of such reports have not been fully actualized amongst wastewater system practitioners. A lucid drive towards implementing ARGs/MGEs removal strategies from the environment by applying affirmed research-based methods are suggestive.

A Global Perspective of Vibrio Species and Associated Diseases: Three-Decade Meta-Synthesis of Research Advancement.

Outbreaks of Vibrio infections have a long history of global public health concern and threat to the aquaculture industry. This 3-decade (1990-2019) meta-synthesis of global research progress in Vibrio species and associated disease outbreaks was undertaken to generate the knowledge needed to design effective interventions with policy implications. Using PRISMA protocol, we obtained data on the online version of the Institute for Scientific Information (ISI), Web of Science (WOS), and Scopus from January 1990 to September 2021 by title search of the keywords "Vibrio species OR Vibrio spp. OR vibriosis." On the 3-decade survey, the result has shown that a total of 776 publications document types were published on the subject, with an average of 24.25 ± 13.6 published documents per year with an annual growth rate of 4.71%. The year 2020 recorded the highest output of 52 published documents accounting for 6.70% of the total. The most prolific author, Blanch A., published 12 articles on the subject and has received citations of 1003 with an h-index of 10. While the most global cited paper author is the journal of J. Bacteriol (Bassler et al), receiving total citation (TC) (550) and per Year (22). The top active corresponding authors country is the United States of America with (92) articles, freq. 12.40%; TC of 3103. The observations in this study, such as the collaborations network map, and index, which have outlined a big difference between countries based on economic status, have underscored the need for a sustained research mentorship program that can define future policies.

Systematic review and meta-analysis of environmental Vibrio species - antibiotic resistance.

Adequate comprehension of the genomics of microbial resistance to an antimicrobial agent will advance knowledge on the management of associated pathologies and public health safety. However, continued emergences and reemergence of pathogens, including Vibrio species, hallmarks a potential knowledge gap. A clear understanding of the process and forecast of the next trend should be in place to nip in the bud, microbial acquisition of resistance to antibiotics. Therefore, this two-decade (1 January 2000 to 31 December 2019) systematic review and meta-analytical study articulated the prevalence and incidence of antibiotics resistance genes in Vibrio species isolated from environmental samples. Articles from the Web of Science and PubMed electronic databases was engaged. Heterogeneity of the data and bias were analyzed with random effect model meta-analysis and funnel plot. A total of 1920 Vibrio sp. were reported by the ten selected articles included in this study; out of which 32.39% of identified isolates displayed antimicrobial resistance and associated genes. The distribution of antibiotics resistance genes in Vibrio sp., reported within six countries was 21% tetracycline (tet), and 20% sulphonamide (sul) and ß-lactamase (bla) respectively. The quinolone, tetracycline and sulfonamide resistance genes showed 32.97% (95% CI 0.18-0.53) prevalence while chloramphenicol, macrolides and aminoglycoside resistance genes are expressed in percentages as 28.67% (95% CI 0.15-0.47) and ß-lactamase resistance genes 27.93% (95% CI 0.11-0.56) respectively. The Vibrio antibiotics resistance genes (V-ARG) distribution depicts no regular trend or pattern from the analyzed data. Consequently, more studies would be required to articulate the structure of cohesion in the distribution of the resistance determinants in microbes.

In vivo evaluation of the antiviral activity of Cajanus cajan on measles virus.

Cajanus cajan, a tropical shrub, serves as source of food and traditional medicines. The evaluation of aqueous and ethanol extracts for activity against measles virus and toxicity to embryonated chicken eggs was carried out in this study. In vivo and in vitro assay techniques using embryonated chicken eggs and tissue culture (Hep-2 cell lines) as media for both virus cultivation and anti-virus assay showed that a hot-water extract yielded higher activity against measles virus. The hot-water extract of the stem yielded a Log(2) titre of 0.1 for the in vivo assay and an inhibition of cytopathic effect (CPE) in Hep-2 cells by 100% for the in vitro assay. At all concentrations of the extracts, there was a lowering of virus concentration (p = 0.05), indicated by hemagglutination (HA) titration, which is the advantage of HA titration over the tissue culture technique using CPE. This study validates embryonated chicken eggs as suitable media for anti-virus assay and the use of C. cajan in the treatment of some diseases of viral origin.

Antibiogram profile and virulence signatures of Pseudomonas aeruginosa isolates recovered from selected agrestic hospital effluents.

Hospital wastewater (HWW) harbours diverse microbial species and a miscellany of genome that would facilitate the emergence of novel pathogen upon genome integration that manifests novel traits in infectious pathogens. The study aimed to determine the antibiogram, and virulence signatures of Pseudomonas aeruginosa (P. aeruginosa) recovered from selected agrestic hospital effluents in Eastern Cape, South Africa. Thirty-six (36) wastewater samples were collected from selected hospital drains between February 2018 and April 2018, processed and analyzed by culture-dependent methods for the isolation of P. aeruginosa. The identity confirmation of isolates was achieved by amplification of oprl and oprL genes. Antibiogram was done using standard disk diffusion technique of Kirby-Bauer as approved by CLSI 2018 guidelines. Virulence signatures (lasA, lasB, toxA, popB) among isolates were analysed using polymerase chain reaction. A total of 54 P. aeruginosa isolates were confirmed by amplification of oprl and oprL genes in the hospital wastewater effluent samples. The isolates showed a 100% susceptibility to gentamicin, amikacin and imipenem antimicrobial agents. Ceftazidime recorded the most resistance (63%) against the isolates studied. Other antibiotics had a resistance range of 7% and 35%. The MAR index among the isolates revealed a range of 0.23 and 0.38. ToxA virulence gene was detected in all isolates while popB, lasB, lasA were detected in 82%, 75% and 54% of the isolates. This study reveals P. aeruginosa isolates with virulence traits and some strains showing multiple antibiotic resistance. The multiple antibiotic resistance index (MARI) of ≥ 0.2 indicates that the some isolates may have emerged from high-risk sources, thus projecting a risk to public health. However, with the high sensitivity pattern observed among the studied isolates, most of the antibiotics used in the susceptibility tests are not at peril. Hence, the use of these antibiotics is encouraged for treatment of infection attributed to P. aeruginosa. It is also pertinent to initiate strict control and rigid antibiotics therapeutic policy with surveillance programmes for multidrug-resistant pathogens to forestall the development and transmission of resistance traits in the pathogens.

Production of polyextremotolerant laccase by Achromobacter xylosoxidans HWN16 and Citrobacter freundii LLJ16.

Given the upwelling of a variety of potential applications laccases could participate in, it would be fitting to equally make available laccases that are well suited for the aforementioned. Therefore historian understanding of the catalytic and physicochemical properties is desirable. Owing to this, the biochemical properties of the crude laccases from Achromobacter xylosoxidans HWN16 (Hb9c) and Citrobacter freundii LLJ 16 (Ie1c) were assessed. Furthermore, a hint of the molecular basis for their production from respective organisms was presented. Results showed that both laccases were tolerant, and sometimes had their activities improved by the set of parameters tested. They were active at broad range of temperature (0-90 °C), pH (3-11), and were equally thermo- and pH-stable. Their activities were either improved, or left unabated by cations, detergents, and chloride (5-40%), however, the highlight of the study was their augmented activity, when they were incubated with certain concentrations of fluoride (2-20%), a potent inhibitor. They were depicted to have multiple homologous laccase encoding genes, on molecular evaluation, which may be responsible the conferral of these remarkable qualities they possess. Therefore, the laccases might be beneficial, if employed in formulations for a wide range of environmental and biotechnological applications. Moreover, the molecular machinery of their production be exploited for economical benefits in the immediate future.

Incidence and Molecular Characterization of Hepatitis E Virus from Swine in Eastern Cape, South Africa.

Hepatitis E virus-mediated infection is a serious public health concern in economically developing nations of the world. Globally, four major genotypes of HEV have been documented. Hepatitis E has been suggested to be zoonotic owing to the increase of evidence through various studies. Thus far, this paper reports on prevalence of hepatitis E virus among swine herd in selected communal and commercial farms in the Eastern Cape Province of South Africa. A total of 160 faecal samples were collected from swine herds in Amathole and Chris Hani District Municipalities of Eastern Cape Province for the presence of HEV. Of the 160 faecal samples screened, only seven were positive (4.4%) for HEV. The nucleotide sequences analyses revealed the isolates as sharing 82% to 99% identities with other strains (KX896664, KX896665, KX896666, KX896667, KX896668, KX896669, and KX896670) from different regions of the world. We conclude that HEV is present among swine in the Eastern Cape Province, albeit in low incidence, and this does have public health implications. There is a need for maintenance of high hygienic standards in order to prevent human infections through swine faecal materials and appropriate cooking of pork is highly advised.

Bioflocculation potentials of a uronic acid-containing glycoprotein produced by Bacillus sp. AEMREG4 isolated from Tyhume River, South Africa.

Bioflocculants are secondary metabolites produced by microorganisms during their growth which have received attentions due to their biodegradability, innocuousness and lack of secondary pollution from degradation intermediates. This study reports on a bioflocculant produced by Bacillus specie isolated from Thyume River in South Africa. The bacterial isolate was identified through 16S rDNA sequencing and the BLAST analysis of the nucleotide sequences revealed 99% similarity to Bacillus sp. BCT-7112. The sequence was subsequently deposited in the GenBank as Bacillus sp. AEMREG4 with accession number KP406729. The optimum culture conditions for bioflocculant production were an inoculum size 4% (v/v) (80%) and starch (81%) as well as yeast extract (82%) as sole carbon and nitrogen sources, respectively. Addition of Ca2+ greatly enhanced the flocculating activity (76%) of crude bioflocculant over a wide range of pH 4-10 and retained high flocculating activity when heated at 100 °C for 1 h. Chemical analyses of the purified bioflocculant revealed carbohydrate (79% w/w) as a predominant component followed by uronic acid (15% w/w) and protein (5% w/w). Fourier transform infrared spectrum revealed the presence of carboxyl, hydroxyl and methoxyl groups as the functional groups responsible for flocculation and the high flocculation activity achieved portends its industrial applicability.

Assessment of overweight and obesity among Nigerian children and adolescents using triceps skin-fold thickness and body mass index.

The prevalence of obesity is increasing in children and adolescents even in resource-poor countries. The study aimed to determine the prevalence of obesity in a group of Nigerian school children using triceps skin-fold thickness (SFT) and body mass index (BMI). The subjects were 1235 randomly selected primary and secondary Lagos school children aged 5-18 years, triceps SFT was measured with Harpenden® calipers and BMI calculated from weight and height. Using BMI, overweight and obesity were defined as values of 85th to 94th percentile for age and sex and ≥95th percentile, respectively. Using triceps SFT, obesity was defined as SFT > 85th percentile of the NHANES III study. Fifty-seven subjects (15 boys and 42 girls) had SFT > 85th percentile with a higher prevalence in girls than boys (6.4% vs. 2.6%, P = 0.001). The prevalence of BMI-defined overweight and obesity were also higher among girls (11.9% vs. 5.7%, P < 0.001 and 4.7% vs. 2.2%, P = 0.02, respectively). Females of upper socioeconomic class were more likely to be overweight (16.2% vs. 6.6%, P < 0.0001), obese (6.3% vs. 2.8%, P = 0.03) or have elevated SFT (8.2% vs. 4.2%, P = 0.03) than those of low socioeconomic status. Forty-seven of 57 subjects (82.5%) with elevated SFT also had high BMI. The prevalence of obesity is low in the study population but the much higher prevalence of overweight suggests that steps should be taken to control fatness before the figures worsen. In more than 80% of subjects, elevated SFT co-existed with elevated BMI.