Crude extracts activity of three selected medicinal plants from the Venda region against some pathogenic organisms.

Background: The emerging of antimicrobial resistance has become a problem as it is threatening public health worldwide. Objectives: To extract crude extracts from three different medicinal plants, test activity against Mycobacterium smegmatis, Staphylococcus aureus and Escherichia coli and screen for phytochemicals of those that showed activity against the targeted bacteria. Methods: KirkiaacuminataOliv., Dichrostachyscinerea (L.) Wight &Arn. and MimusopszeyheriSond. plants were collected at Thengwe area, Mafukani village, Limpopo Province, South Africa. The plant materials collected were extracted using four solvents. Antimicrobial screening was accomplished using the agar well diffusion method and the crude extracts that showed activity against the targeted organisms were screened for phytochemicals using different tests. Results: With all solvents used for extraction, methanol had a greater yield of 14.1% from Dichrostachyscinerea crude extracts. Kirkiaacuminata and Dichrostachyscinerea were medicinal plants that inhibited Mycobacterium smegmatis and Staphylococcus aureus at the lowest concentration of 2.5 mg/ml and 1.25 mg/ml. Conclusions: The results from this study show that the selected medicinal plants are active against Mycobacterium smegmatis and Staphylococcus aureus and their pharmacological properties can be further analyzed for the development of new drugs.

Investigating the Toxicity of Compounds Yielded by Staphylococci on Vero Cells.

Bacterial secondary metabolites play a major role in the alleviation of diseases; however, the cytotoxicity of other metabolites cannot be ignored as such metabolites could be detrimental to human cells. Three Staphylococci strains Staphylococcus aureus, staphylococcus epidermidis and staphylococcus saprophyticus were used in the experiments. These strains are well known to cause hospital and community-acquired infections. Secondary metabolites from S. aureus isolated from milk of cows with clinical features of mastitis (swollen udders and the production of watery clotted milk), S. saprophyticus (ATCC 35552), and S. epidermidis (ATCC 51625) were exposed to a minimal medium then screened using Gas Chromatography High-Resolution Time-of-flight Mass Spectrometry (GC-HRTOF-MS) and identified with Nuclear Magnetic Resonance (NMR). From S. epidermidis, two compounds were isolated: oleamide and methyl palmitate; three from S. aureus, including fluoranthene, 3-methyl-2-phenyl-1H-pyrrole, and cyclo(L-Leu-L-Propyl); while S. saprophyticus yielded succinic acid, 1,2,6-hexantriol, veratramine, and 4-methyl-pentyl-amine. The secondary metabolites were tested for cytotoxicity using the Vero cell line. Fluoranthene exhibited toxicity with an LC50 of 0.0167 mg/mL to Vero cells, while the other metabolites did not. Methyl palmitate was the least toxic of all of the metabolites. The results imply that none of the compounds, except fluoranthene, pose any danger to human cells.

Exploring indigenous freshwater chlorophytes in integrated biophotovoltaic system for simultaneous wastewater treatment, heavy metal biosorption, CO2 biofixation and biodiesel generation.

The study explored the combined photosynthetic activities of two green microalgal species, Tetradesmus obliquus and Tetradesmus reginae, on an integrated biophotovoltaic (BPV) platform for simultaneous wastewater treatment, toxic metal biosorption, carbon biofixation, bioelectricity generation and biodiesel production. The experimental setup comprised of a dual-chambered BPV with copper anode surrounded by T. obliquus in BG11 media, and copper cathode with T. reginae in municipal wastewater separated by Nafion 117 membrane. The study reported a maximum power density of 0.344 Wm-2 at a cell potential of 0.415 V with external resistance of 1000 Ω and 0.3268 V maximum open-circuit voltage. The wastewater electrical conductivity and pH increased from 583 ± 22 to 2035 ± 29.31 mS/cm and 7.403 ± 0.174 to 8.263 ± 0.055 respectively, signifying increased photosynthetic and electrochemical activities. Residual nitrogen, phosphorus, chemical oxygen demand, arsenic, cadmium, chromium and lead removal efficiencies by T. reginae were 100%, 80.68%, 71.91%, 47.6%, 88.82%, 71.24% and 92.96%, respectively. T. reginae accumulated maximum biomass of 0.605 ± 0.033 g/L with a CO2 biosequestration rate of 0.166 ± 0.010 gCO2/L/day and 42.40 ± 1.166% lipid content. Methyl palmitate, methyl undecanoate and 13-octadecenoic acid with relative abundances of 37.24%, 24.80% and 12.02%, respectively were confirmed.

Antibiogram Screening and Detection of Virulence-Associated Genes in Brucella Species Acquired from Cattle in South Africa's Eastern Cape Province.

Brucellosis is a widespread zoonotic illness, and it poses serious public health and economic risks. The purpose of this investigation is to look at the antimicrobial susceptibility of unpasteurized milk, blood, and lymph node specimens from cattle, goats, and sheep, as well as to identify virulence-associated genes. In this investigation, a total of 123 isolates were examined. The activity of 15 antimicrobials against Brucella pathogens were assessed using the Kirby−Bauer disk diffusion technique. Nine virulence factors were detected with polymerase chain reaction analysis. Five antibiotics were 100% effective against Brucella isolates. A high level of resistance (100%) was documented with streptomycin, penicillin, and seven more antibiotics. Doxycycline resistance was found in 12% of goat isolates, and tetracycline resistance was found in 21% and 44% of goat and sheep isolates, respectively. Multiple antibiotic resistance (MAR) index >0.2 was found in 38.2% (47/123) of Brucella isolates. VecC and BetB, two B. abortus genes, were confirmed to be comparable. The findings of this study suggests that Brucella spp. are reservoirs of antibiotic resistance in the Eastern Cape Province. As such, they represent a potential pool of antibiotic genes that might be transferred to other pathogens in the community, and thus continue to pose a healthcare hazard.

Antimicrobial Susceptibility Profiles among Pseudomonas aeruginosa Isolated from Professional SCUBA Divers with Otitis Externa, Swimming Pools and the Ocean at a Diving Operation in South Africa.

SCUBA divers are predisposed to otitis externa caused by Pseudomonas aeruginosa, which is becoming increasingly multi-drug resistant (MDR). The present work assessed the antibiotic resistance profiles of P. aeruginosa obtained from SCUBA divers and their environment in Sodwana Bay, South Africa. Bacterial isolates from a total of 137 random water and ear swab samples were identified using biochemical and molecular methods. P. aeruginosa strains were further evaluated for antibiotic susceptibility using the Kirby-Bauer assay. Double disk synergy test (DDST) to confirm metallo-ß-lactamase (MBL) production and PCR amplification of specific antibiotic resistance genes was performed. All (100%) 22 P. aeruginosa isolates recovered were resistant to 6 of the ß-lactams tested including imipenem but exhibited susceptibility to trimethoprim-sulfamethoxazole. MBL production was observed in 77% of isolates while the most prevalent extended-spectrum ß-lactamase (ESBL) genes present included blaAmpC (86.9%) followed by blaTEM (82.6%). Sulfonamide resistance was largely encoded by sul1 (63.6%) and sul2 (77.3%) genes with a high abundance of class 1 integrons (77.3%) of which 18.2% carried both Intl1 and Intl2. P. aeruginosa found in Sodwana Bay exhibits multi-drug resistance (MDRce) to several pharmaceutically important drugs with the potential to transfer antibiotic resistance to other bacteria if the judicious use of antibiotics for their treatment is not practiced.

Physicochemical Properties and Bacterial Community Profiling of Optimal Mahewu (A Fermented Food Product) Prepared Using White and Yellow Maize with Different Inocula.

Mahewu is a fermented food product from maize, commonly consumed in Southern Africa. This study investigated the effect of optimizing fermentation (time and temperature) and boiling time of white maize (WM) and yellow maize (YM) mahewu, with the use of the Box-Behnken-response surface methodology (RSM). Fermentation time and temperature as well as boiling time were optimized and pH, total titratable acidity (TTA) and total soluble solids (TSS) determined. Results obtained showed that the processing conditions significantly (p ≤ 0.05) influenced the physicochemical properties. pH values of the mahewu samples ranged between 3.48-5.28 and 3.50-4.20 for YM mahewu and WM mahewu samples, respectively. Reduction in pH values after fermentation coincided with an increase in TTA as well as changes in the TSS values. Using the numerical multi-response optimisation of three investigated responses the optimal fermentation conditions were observed to be 25 °C for 54 h and a boiling time of 19 min for white maize mahewu and 29 °C for 72 h and a boiling time of 13 min for yellow maize mahewu. Thereafter white and yellow maize mahewu were prepared with the optimized conditions using different inocula (sorghum malt flour, wheat flour, millet malt flour or maize malt flour) and the pH, TTA and TSS of the derived mahewu samples determined. Additionally, amplicon sequencing of the 16S rRNA gene was used to characterise the relative abundance of bacterial genera in optimized mahewu samples, malted grains as well as flour samples. Major bacterial genera observed in the mahewu samples included Paenibacillus, Stenotrophomonas, Weissella, Pseudomonas, Lactococcus, Enterococcus, Lactobacillus, Bacillus, Massilia, Clostridium sensu stricto 1, Streptococcus, Staphylococcus, Sanguibacter, Roseococcus, Leuconostoc, Cutibacterium, Brevibacterium, Blastococcus, Sphingomonas and Pediococcus, with variations noted for YM mahewu and WM mahewu. As a result, the variations in physicochemical properties are due to differences in maize type and modification in processing conditions. This study also discovered the existence of variety of bacterial that can be isolated for controlled fermentation of mahewu.

Kinetics of Phenolic Compounds Modification during Maize Flour Fermentation.

This study aimed to investigate the kinetics of phenolic compound modification during the fermentation of maize flour at different times. Maize was spontaneously fermented into sourdough at varying times (24, 48, 72, 96, and 120 h) and, at each point, the pH, titratable acidity (TTA), total soluble solids (TSS), phenolic compounds (flavonoids such as apigenin, kaempferol, luteolin, quercetin, and taxifolin) and phenolic acids (caffeic, gallic, ferulic, p-coumaric, sinapic, and vanillic acids) were investigated. Three kinetic models (zero-, first-, and second-order equations) were used to determine the kinetics of phenolic modification during the fermentation. Results obtained showed that fermentation significantly reduced pH, with a corresponding increase in TTA and TSS. All the investigated flavonoids were significantly reduced after fermentation, while phenolic acids gradually increased during fermentation. Among the kinetic models adopted, first-order (R2 = 0.45-0.96) and zero-order (R2 = 0.20-0.82) equations best described the time-dependent modifications of free and bound flavonoids, respectively. On the other hand, first-order (R2 = 0.46-0.69) and second-order (R2 = 0.005-0.28) equations were best suited to explain the degradation of bound and free phenolic acids, respectively. This study shows that the modification of phenolic compounds during fermentation is compound-specific and that their rates of change may be largely dependent on their forms of existence in the fermented products.

Metabolite data of germinated Bambara groundnut flour and starch extracted with two different solvents.

The data presented in this study represents the profile of metabolites of germinated Bambara groundnut flour (GBF) and starch (GBS) extracted using two different extraction solvents. Bambara groundnuts obtained from a local agro market in Minna, Niger State, Nigeria were germinated at 28 ± 1°C for 24, 48 and 72 h, dried and then processed into flour and starch. Raw Bambara groundnuts (0 h) were also processed into flour and starch and served as controls. Samples at the different germination times were extracted using methanol/water (80:20v/v) and acetonitrile/methanol/water (40:40:20 v/v/v), concentrated, reconstituted and analysed on a gas chromatography-high resolution time of flight-mass spectrometer (GC-HRTOF-MS). Data obtained were classified into compound groups such as acids, alcohols, cyclic compounds, esters, ketones, phytosterols, vitamins and many others, and their characteristics such as the retention time, observed mass, molecular formular and mean peak areas were reported. These data represent the collection of metabolites in GBF and GBS and may be useful for the identification and utilization of functional compounds in foods.

Photorhabdus sp. ETL Antimicrobial Properties and Characterization of Its Secondary Metabolites by Gas Chromatography-Mass Spectrometry.

Entomopathogenic nematodes (EPNs) are known to be highly pathogenic to insect pests, due to their associated symbiotic bacteria, which produce virulence factors, exo-enzymes and other harmful secondary metabolites to conquer, kill, and degrade their insect hosts. However, these properties are not fully characterized. This study reports on the antimicrobial activities of Photorhabdus sp. strain ETL, symbiotically associated to an insect pathogenic nematode, Heterorhabditis zealandica, against human pathogenic bacteria and toxigenic fungi, as well as the non-targeted profiling of its secondary metabolites (SMs) using gas chromatography coupled to high-resolution time-of-flight mass spectrometry. Fatty acids including 3-eicosene, (E)-; 5-eicosene, (E)-; eicosene; 9-octadecenamide; undecanoic acid with shown antimicrobial activities were detected. This provided more insight on the composition and bioactivities of SMs produced by the Photorhabdus sp.

Genome assembly and annotation of Photorhabdus heterorhabditis strain ETL reveals genetic features involved in pathogenicity with its associated entomopathogenic nematode and anti-host effectors with biocontrol potential applications.

The genome sequences of entomopathogenic nematode (EPN) bacteria and their functional analyses can lead to the genetic engineering of the bacteria for use as biocontrol agents. The bacterial symbiont Photorhabdus heterorhabditis strain ETL isolated from an insect pathogenic nematode, Heterorhabditis zealandica strain ETL, collected in the northernmost region of South Africa was studied to reveal information that can be useful in the design of improvement strategies for both effective and liquid production method of EPN-based pesticides. The strain ETL genome was found closely related to the type strain genome of P. australis DSM 17,609 (~60 to 99.9% CDSs similarity), but closely related to the not yet genome-sequenced type strain, P. heterorhabditis. It has a genome size of 4,866,148 bp and G + C content of 42.4% similar to other Photorhabdus. It contains 4,351 protein coding genes (CDSs) of which, at least 84% are shared with the de facto type strain P. luminescens subsp. laumondii TTO1, and has 318 unknown CDSs and the genome has a higher degree of plasticity allowing it to adapt to different environmental conditions, and to be virulent against various insects; observed through genes acquired through horizontal gene transfer mechanisms, clustered regularly interspaced short palindromic repeats, non-determined polyketide- and non-ribosomal peptide- synthase gene clusters, and many genes associated with uncharacterized proteins; which also justify the strain ETL's genes differences (quantity and quality) compared to P. luminescens subsp. laumondii TTO1. The protein coding sequences contained genes with both bio-engineering and EPNs mass production importance, of which numerous are uncharacterized.

Chemotaxonomic profiling of fungal endophytes of Solanum mauritianum (alien weed) using gas chromatography high resolution time-of-flight mass spectrometry (GC-HRTOF-MS).

INTRODUCTION: Since ancient times medicinal plants have been used as medicine in many parts of the world to promote human health and longevity. In recent years many novel secondary metabolites of plants have been isolated and reported to provide lead compounds for new drug discoveries. Solanum mauritianum Scopoli is native to South America. It is reported to be used by native South Americans during famine as a vegetable and as medicine to cure various diseases. In South Africa the plant is viewed as weed and is facing eradication, however, this plant is a valuable subject for research into its potential pharmaceutical and chemical uses. This study elucidated the metabolic profile of fungal endophytes that have promising bioactive secondary metabolites against pathogenic microorganisms, including mycobacterium species. MATERIAL AND METHODS: Fungal endophytes from a weed Solanum mauritianum Scop. were used to synthesize secondary metabolites. Gas chromatograph high-resolution time-of-flight mass spectrometry (GC-HRTOF-MS) was used to analyse volatile compounds to prove that potentially fungal endophytes could be extracted from this weed. Extracts obtained with ethyl acetate were screened for phytochemicals and analyzed using a gas chromatograph high-resolution time-of-flight mass spectrometry system. Principal component analysis was used to compare the gas chromatograph high-resolution time-of-flight mass spectrometry data for differences/similarities in their clustering. Phytochemical screening was conducted on the crude extracts of fungal endophytes obtained from different parts of Solanum mauritianum Scopoli (leaves, ripe fruit, unripe fruit and stems). RESULTS: Phytochemical screening indicated the presents of alkaloids, flavonoids, glycosides, phenols, quinones and saponins. Quinones were not present in the crude extracts of Fusarium sp. A total of 991 compounds were observed in the fungal endophytes, and Cladosporium sp. (23.8%) had the highest number of compounds, compared to Paracamarosporium leucadendri (1.7%) and Talaromyces sp. (1.5%). Some volatile compounds such as eicosane, 2-pentadecanone, 2-methyloctacosane, hexacosane and tridecanoic acid methyl ester with antibacterial activity were also observed. CONCLUSION: Compositional variations between the plant and fungal endophyte phytochemicals were observed. The results of this study indicate that fungal endophytes from Solanum mauritianum Scop. contain compounds that can be exploited for numerous pharmaceutical and medicinal applications.

Metabolomic approaches for the determination of metabolites from pathogenic microorganisms: A review.

Metabolomics is a high precision analytical approach to obtaining detailed information of varieties of metabolites produced in biological systems, including foods. This study reviews the use of metabolomic approaches such as liquid chromatography mass spectrometry (LCMS), gas chromatography mass spectrometry (GC-MS), matrix assisted laser desorption /ionization tandem time of flight mass spectrometry (MALDI-TOF-MS) and nuclear magnetic resonance (NMR) for investigating the presence of foodborne pathogens and their metabolites. Pathogenic fungi and their notable metabolites (mycotoxins) have been studied more extensively using metabolomics as compared to bacteria, necessitating further studies in this regard. Nevertheless, such identified fungal and bacteria metabolites could be used as biomarkers for a more rapid detection of these pathogens in food. Other important compounds detected through metabolomics could also be correlated to functionality of these pathogenic strains, determined by the composition of the foods in which they exist, thereby providing insights into their metabolism. Considering the prevalence of these food pathogens, metabolomics still has potentials in the determination of food-borne pathogenic microorganisms especially for the determination of pathogenic bacteria toxins and is expected to generate research interests for further studies and applications.

Physical properties and water absorption kinetics of three varieties of Mucuna beans.

The physical properties and water absorption kinetics of three varieties of Mucuna beans (Mucuna pruriens, Mucuna rajada and Mucuna veracruz) were determined in this study. Physical properties including length, width, thickness, geometric mean diameter, sphericity, porosity, bulk density, area, volume and one thousand seed mass were calculated while hydration kinetics was studied by soaking Mucuna beans in water at 30 °C, 40 °C and 50 °C and measuring water uptake at 9 h interval. Peleg's equation was used to model the hydration characteristics and Arrhenius equation was used to describe the effect of temperature on Peleg's rate constant k1 and to obtain the activation energies for soaking. Significant variations were observed in almost all the physical properties of the different varieties, however, there were no significant differences (p < 0.05) in their thicknesses and bulk densities. The effectiveness of fit of Peleg's model (R2) increased with increase in soaking temperature. Peleg's rate constant k1 decreased with increase in soaking temperature while k2 increased with temperature increase. Activation energies of Mucuna pruriens, Mucuna rajada and Mucuna veracruz were 1613.24 kJ/mol, 747.95 kJ/mol and 2743.64 kJ/mol, respectively. This study provides useful information about the properties of three varieties of Mucuna beans that could be of importance to processors and engineers for process design and optimization.

Molecular characterization and antimicrobial resistance profiles of Mycobacterium tuberculosis complex in environmental substrates from three dairy farms in Eastern Cape, South Africa.

This study analysed 330 environmental substrates from three dairy farms for the occurrence, drug resistance and the genetic mutations of MTBC (Mycobacterium tuberculosis complex) in Eastern Cape, South Africa using PCR, while the Genotype MTBDRplus assay was used for drug susceptibility and genetic mutations analyses. About 17% (55/330) of the samples were positive for MTBC at 16.7% (water), 13.3% (soil) and 20% (hayfeed). Isoniazid resistance was detected in 47.3% (26/55) of the samples while 16.4% (9/55) were multidrug-resistant. Genetic mutations were detected on the rpoB gene (resistance to rifampicin) with frequencies ranging from 53.6% (D516V) to 21.4% (H526D), while mutations on the katG and inhA genes (resistance to isoniazid) ranged between 14.3% and 80%. Incidents of diverse genetic mutations in the environmental matrices suggest possible resistance to other anti-TB drugs not assayed in this study and emphasizes the need for continuous monitoring of drug resistance patterns for timely detection and control of new clonal groups of MTBC.

Antimicrobial Resistance Phenotype of Staphylococcus aureus and Escherichia coli Isolates Obtained from Meat in the Formal and Informal Sectors in South Africa.

BACKGROUND: Foodborne diseases (FBD) caused by resistant pathogens are a global public health problem. One main driver of the increasing FBD incidence is the transfer of pathogenic organisms from animal guts to carcasses during processing and subsequent transfer from meat products to consumers. METHODS: In this study, meat samples from abattoirs in the formal meat sector (FMS) (n = 140) and slaughter points in the informal meat sector (IMS) (n = 104) were collected for microbial detection and phenotypic AMR determination using polymerase chain reaction. RESULTS: The antibiogram of Staphylococcus aureus isolates revealed that resistance to clindamycin (74.3%) and ampicillin (59.5%) was highest in the FMS, while resistance to penicillin (83.8%) and tetracycline (82.1%) was highest in the IMS. Escherichia coli isolates show significant resistance to chloramphenicol (90.7%) and tetracycline (82.3%) in the FMS. Likewise, resistance to tetracycline (92.3%) and sulfamethoxazole/trimethoprim (87.5%) was highest in the IMS. The multiple antibiotic resistance index (MARI) for S. aureus and E. coli ranged from 0.3 to 0.8 and 0.2 to 0.5, respectively. CONCLUSION: This study suggests high-level contamination of meat with resistant pathogens and highlights the public health consequences associated with consuming such unhygienic products.

Evaluation of Fecal Coliform Prevalence and Physicochemical Indicators in the Effluent from a Wastewater Treatment Plant in the North-West Province, South Africa.

Compliance of the effluents from wastewater treatment plants (WWTPs) to the regulatory standards, which mostly entail the removal/reduction of organic waste and deactivation of the potential microbial pathogens is of great importance. The detection of indicator parameters can be used to determine the effectiveness of a WWTP and the level of compliance with the South African regulatory standards. The performance of the WWTP was assessed by biological, physical and chemical measures in wastewater final effluent. The Escherichia coli ranged from 0 and 2420 count/100 mL in the final effluent. The recorded values for the physicochemical parameters were within the following ranges: pH (7.03-8.49), electrical conductivity (81.63-126.5 mS/m), suspended solids (0.40-20.4 mg/L), ammonia (0-22.15 mg/L), Chemical Oxygen Demand (COD) (1-73 mg/L), nitrate (0-16.1 mg/L), ortho-phosphate (0-8.58 mg/L) and free chlorine (0-3.21 mg/L). Furthermore, the concentration of toxic heavy metals was recorded to be between 1-10 ug/L for arsenic, cadmium, lead and mercury. In conclusion, all the parameters that were evaluated in this study indicate that the studied WWTP is performing in accordance with the prescribed general limits.

Erratum to "Seasonal prevalence, body condition score and risk factors of bovine fasciolosis in South Africa" [4C (December 2017) 1-7].

[This corrects the article DOI: 10.1016/j.vas.2017.06.001.].

Characterization of mutations in the rpoB gene conferring rifampicin resistance in Mycobacterium tuberculosis complex isolated from lymph nodes of slaughtered cattle from South Africa.

Tuberculosis (TB) is an ongoing public health care, with the state of affairs exacerbated by the growth of anti-TB drug-resistant forms in South Africa. Not much attention is given to zoonotic TB. Thus, this study aimed to determine the presence of rpoB mutations among Mycobacterium tuberculosis complex (MTBC) isolates of lymph nodes from slaughtered cattle. A count of 14,950 carcasses from selected abattoirs were examined for nodular lesions and enlarged lymph nodes; 376 lymph nodes were cultured for MTBC. Positive isolates were tested for drug sensitivity against three anti-TB drugs, rifampicin, isoniazid, and ethambutol, using the Lowenstein-Jensen proportion method. Rifampicin-resistant isolates were sequenced, and spoligotyping was performed for lineage classification. A total of 162 isolates were confirmed as MTBC and 42 isolates were resistant to rifampicin. All rifampicin-resistant isolates carried the H526D rpoB mutation, and almost all of them carried an additional nonsynonymous nucleotide substitution in the hot spot region, in three other codons (510, 516 and 522). In total, 5 different mutations at four codons are reported, including one isolate showing 3 of them which has never been reported in South Africa. In addition, we report 4 different spoligo patterns, with 34 isolates known and 8 unknown spoligotype international types. From the known clades, 5 (11.9%) isolates were identified as Bov_4 caprae lineage, 29 (69%) Beijing, and 8 (19.1%) remaining unknown clades. The detection of MTBC-resistant patterns from cattle lymph nodes (Eastern Cape, South Africa) necessitates the investigation of other possible routes of MTBC transmission.

Prevalence and distribution of antimicrobial resistance determinants of Escherichia coli isolates obtained from meat in South Africa.

OBJECTIVE: This study aimed to characterise antibiotics resistance of Escherichia coli isolates from the formal meat sector (FMS) and informal meat sectors (INMS). METHOD: A total of 162 and 102 E. coli isolates from the FMS, and INMS respectively were isolated by standard culture-based, and biochemical reactions. The isolates were further confirmed by polymerase chain reaction (PCR). The disc diffusion method was used to screen for antimicrobial susceptibility against 19 different antibiotics. The presence of class 1-2 integrons in each E. coli isolates was assessed using 3'-CS and 5'-CS regions specific primers. RESULT: Among the 19 antimicrobials, resistance to tetracyclines, aminoglycosides, cephalosporins, and nitrofurans were found to be more frequent than carbapenems and chloramphenicol. The number of multi-drug resistance ranged from three to ten antimicrobials. The resistant determinants with the highest prevalence in the FMS and INMS were; [aminoglycosides: aadA (40.6%; 31.9%), and strA (6.5%; 9.4%)], [ß-lactams: ampC (20%; 45%),], [Chloramphenicol: catI (1.7%; 1.7%), and [tetracyclines: tetB (11.5%; 24%),], and [sulfonamides: sul1 (22.2%; 26.7%),]. CONCLUSION: Higher phenotypic resistance to cephalosporins and carbapenems were found in the FMS than in INMS. The multiple antibiotic resistance (MAR) indexes for FMS and INMS ranged from 0.2-0.5. The results reveal a high prevalence of multidrug-resistant E. coli isolates and resistance determinants, suggesting that consumers and handlers of such meat are at risk of contracting antibiotic-resistant E. coli-related foodborne disease.

Diversity and Antimicrobial Activity of Culturable Fungal Endophytes in Solanum mauritianum.

Plant endophytes are microbial sources of bioactive secondary metabolites, which mimic the natural compounds chemistry of their respective host plants in a similar manner. This study explored the isolation and identification of fungal endophytes, and investigated the antibacterial and antimycobacterial activity of their crude extracts. Fungal endophytes were isolated from Solanum mauritianum, identified using morphological traits and internal transcribed spacer ribosomal-deoxyribonucleic acid (ITS-rDNA) sequence analysis. Eight fungal endophytes were identified as Aureobasidium pullulans, Paracamarosporium leucadendri, Cladosporium sp., Collectotrichum boninense, Fusarium sp., Hyalodendriella sp., and Talaromyces sp., while Penicillium chrysogenum was isolated from the leaves and unripe fruits. Good activity was observed for the crude extracts of Paracamarosporium leucadendri inhibiting Mycobacterium bovis, Klebsiella pneumoniae, and Pseudomonas aeruginosa at 6 µg/mL. Crude extracts of Fusarium sp., showed activity at 9 µg/mL against M. bovis, M. smegmatis and K. pneumonia. In general, the crude extracts showed great activity against Gram-negative and Gram-positive bacteria and novel results for two mycobacteria species M. bovis and M. smegmatis. The results provide evidence of diverse fungal endophytes isolated from Solanum mauritianum, and evidence that fungal endophytes are a good source of bioactive compounds with pharmaceutical potential, particularly against Mycobacterium tuberculosis.