Antibacterial activity of the phenolic extract of wild virgin olive oil in vitro

Background: The olive tree (Olea europaea L.), the most widespread plant species in the Mediterranean basin, includes two forms: cultivated (var Europaea) and wild (var Sylvestris). Wild olive trees or oleasters cover large areas in Algeria. It has been shown that oil from oleaster has a higher content of phenolic compounds, which could have antimicrobial properties. Objective:: The objective of this study was to assess the antibacterial activity of phenolic extracts from four Algerian oleaster oils and an extra virgin olive oil (EVOO) from Chemlal variety. Methods: Phenolic compounds were determined by UHPLC-MS. Antibacterial activity was tested against six referenced human enteropathogenic bacteria by the agar disc diffusion method by measuring the diameters of the zone of inhibition. Results: The results revealed a similarity between the phenolic composition of oleasters 1 and 3 and between oleaster 4 and EVOO; however, the phenolic composition of oleaster 2 that the poorer was markedly different with a higher content of free phenolic alcohols and lower in secoiridoids.

First Report of Postharvest Fruit Rot Disease of Yellow Peach Caused by Diaporthe eres in China

The yellow peach (Amygdalus persica), is a fruit crop native to China with golden peel and pulp that is of particular interest in the fruit markets. In August of 2021, yellow peaches showing fruit rot symptoms were purchased from a commercial market in Linyi city, Shandong province, China. The symptoms included circular, tan to brown in color, rotten, necrotic lesions, and whitish mycelium mass in the center of the lesions. The infected fruit were surface disinfected with 1% NaClO for 30 s and rinsed with sterile distilled water three times. Diseased tissues from the infected fruits were cut into small segments, aseptically shifted onto potato dextrose agar media containing petri plates and incubated at 25℃ for 5 days. Eight isolates were obtained in total from two isolation experiments. Fungal colonies were initially white, aerial, fluffy at first, and gradually turned brown to gray, with black stromata at maturity. Alpha conidia were aseptate，hyaline，fusiform to ellipsoidal，and ranged in size from 4.16 to 7.76 µm × 1.95 to 3.14 µm (n=30). Beta conidia were aseptate, hyaline, filiform, curved to hamate, and 15.91 to 22.55 µm × 0.82 to 1.66 µm (n=30). The morphological characteristics were consistent with those of Diaporthe species (Gomes et al. 2013). For further identification, a multigene phylogenetic analysis was carried out. The internal transcribed spacer (ITS) region, translation elongation factor 1-α (TEF1-α), histone H3 (HIS), calmodulin (CAL), and β-tubulin (TUB) genes of two representative isolates were amplified by using primers ITS1/ITS4, EF1-728F/EF1-986R, CYLH3F/H3-1b，CAL228F/CAL737R, and Bt2a/Bt2b (Chaisiri et al. 2021), respectively. The sequences were deposited in GenBank (Accession No. OL375154 for ITS; OL406409 for TEF1-α; OL406410 for HIS; OL106407 for CAL; OL406408 for TUB). phylogenetic analyses were conducted using the concatenation of multiple sequences (ITS, TEF1-α, HIS, CAL, TUB) with Maximum Likelihood (ML) in IQtree v1.5.6 (Nguyen et al. 2015). Based on the morphological and phylogenetic characters, the isolates were identified as D. eres. A Pathogenicity test was performed by wound inoculation on harvested fruits of A. persica Variety ‘Jinxiu’. Mature and healthy yellow peaches purchased from Shandong, Anhui, and Hunan Provinces in China were surface sterilized with 1% NaClO solution for 1 minute, rinsed with sterile water and dried. Each fruit was wounded with a sterile scalpel creating a 2-3 mm incision on the peel. A 5 mm agar disc with mycelium grown on PDA at 28℃ for 7 days was placed on wound and sealed with parafilm. Sterile PDA plugs were used as controls. Ten fruit were used for each treatment and the assays were repeated three times. Inoculated fruit were placed in sterilized transparent plastic cans containing wet, sterile paper towels. After 5 days of incubation at 25℃, the same rot symptoms were observed on fruits inoculated with mycelium and the control remained symptomless. D. eres was re-isolated from the lesions of inoculated fruits and the pathogen identification was confirmed by molecular analysis, thus fulfilling complete Koch’s postulates. Although D. eres was previously reported on peach trees of causing shoot blight (Thomidis and Michailides 2009) and stem canker (Prencipe et al. 2017). To our knowledge, this is the first report of D. eres causing postharvest fruit rot of yellow peach in China and it may lead to considerable economic losses in the peach industry should post-harvest disease management practices not be implemented.

Prevalence and Antifungal Susceptibility Pattern of Candida species Isolated from Patients with Urinary Tract Infections

Background: The presence of Candida species in the urine is termed candiduria, and it is a common form of urinary tract infection (UTI). Many other species of Candida organism apart from Candida albicans are known with increasing the occurrence of resistance to available antifungal agents. Objectives: To determine the prevalence and sensitivity pattern of Candida isolates obtained from urine samples of diagnosed urinary tract infections. Methods: Midstream urine of patients attending the Lagos University Teaching Hospital, Ikeja Lagos, were collected and inoculated on Sabouraud Dextrose Agar (SDA). Microbiological processing was done with Gram reaction, germ tube test, CHROME agar TM and sugar fermentation test using API 32C system. Antifungal susceptibility tests were done using the agar disc diffusion method. Results: Candida species were obtained from 36 (12.9%) of 280 patients with UTI. Candida albicans (CA) had the highest frequency (12; 33.3%) compared to 24 (66.7%) for Non-albicans Candida (NAC). The speciation of Candida using Chrome Agar showed some misidentification from the API32C identification, but there was a significant correlation between API32C and Chrome Agar methods (r = 0. 9793). Half of the C. albicans species were sensitive to fluconazole while C. hellenica was only sensitive to Nystatin. The C. parapsilopsis had the highest susceptibility pattern, with 86% and 71% for fluconazole and ketoconazole, respectively. Generally, ketoconazole had the highest effectiveness on Candida species. Conclusion: This study demonstrated the role of Candida species in UTIs and their high susceptibility to ketoconazole.

Diversity And Antibiograms of Secondary Bacterial Isolates From Cutaneous Leishmaniasis Wounds

Background: Leishmaniasis is a vector borne disease caused by an intracellular protozoan parasite. The presence of secondary bacterial infections in cutaneous leishmaniasis wounds exacerbate lesion development and could lead to delay in the healing process. Little is also known about the different bacteria species co-infecting leishmaniasis wounds and their sensitivity patterns in Ghana. This study sought to determine the resistance patterns of bacteria co-infecting cutaneous leishmaniasis wounds from selected communities in the Nkwanta district.Methods: Various bacteria were isolated and characterized from exudates obtained from wound swabs collected with sterile cotton tipped applicators. Confirmation of bacterial identity was done using the analytical profile index and the matrix-assisted laser desorption/ionization time of flight mass spectrometry. Antibiotic susceptibility tests were performed using agar disc diffusion method according to the Clinical and Laboratory Standards Institute breakpoint values.Results: A total of 42 secondary bacteria were isolated from the wounds among which S. aureus was the most predominant (31%). Other pathogenic bacteria that colonized the wounds included Bacillus subtilis (23.8%), Pantoea spp(11.9%), Klebsiella pneumoniea (7.1%), Enterobacter cloacae (7.1%), Aeromonas spp (4.8%), Serratia marcescens (4.8%),Serratia liquefacien (2.4%), Serratia plymutheca (2.4%), Providencia rettgeri (2.4%) and Cronobacter spp (2.4%). Majority of the isolates were obtained from Agoufie (21.4%), Baasare (19%), and Gekrong (16.7%). Most of the isolates were resistant to beta-lactam antibiotics and the third generation cephalosporin. Notably, 84.6% of the S. aureus isolates were methicillin and ciprofloxacin resistant whilst 92.3% were resistant to ampicllin. About sixty-nine percent (69.2%) showed intermediate susceptibility to Erythromycin. Additionally, S. plymutheca was resistant to all the test antibiotics. All the K. pneumoniae and E. cloacae isolates showed resistance to ampicillin, cefotaxime, ceftriaxone, ciprofloxacin, amikacin, aztreonam and meropenem but only 66.7% of these isolates were resistant to piperacillin. All isolates of Providencia rettgeri, Cronobacter spp, S. marcescen, S. liquefacien were resistant to all the beta-lactam antibiotics.Conclusion: This study suggests colonization of cutaneous leishmaniasis wounds with varied bacterial species that are mostly resistant to beta-lactam group of antibiotics.

Uptake of Ozenoxacin and Other Quinolones in Gram-Positive Bacteria

The big problem of antimicrobial resistance is that it requires great efforts in the design of improved drugs which can quickly reach their target of action. Studies of antibiotic uptake and interaction with their target it is a key factor in this important challenge. We investigated the accumulation of ozenoxacin (OZN), moxifloxacin (MOX), levofloxacin (LVX), and ciprofloxacin (CIP) into the bacterial cells of 5 species, including Staphylococcus aureus (SA4-149), Staphylococcus epidermidis (SEP7602), Streptococcus pyogenes (SPY165), Streptococcus agalactiae (SAG146), and Enterococcus faecium (EF897) previously characterized.The concentration of quinolone uptake was estimated by agar disc-diffusion bioassay. Furthermore, we determined the inhibitory concentrations 50 (IC50) of OZN, MOX, LVX, and CIP against type II topoisomerases from S. aureus.The accumulation of OZN inside the bacterial cell was superior in comparison to MOX, LVX, and CIP in all tested species. The accumulation of OZN inside the bacterial cell was superior in comparison to MOX, LVX, and CIP in all tested species. The rapid penetration of OZN into the cell was reflected during the first minute of exposure with antibiotic values between 190 and 447 ng/mg (dry weight) of bacteria in all strains. Moreover, OZN showed the greatest inhibitory activity among the quinolones tested for both DNA gyrase and topoisomerase IV isolated from S. aureus with IC50 values of 10 and 0.5 mg/L, respectively. OZN intracellular concentration was significantly higher than that of MOX, LVX and CIP. All of these features may explain the higher in vitro activity of OZN compared to the other tested quinolones.

Characterisation of AmpC / ESBL genes in some pathogen gram-negatives isolated from clinical cases of livestock and companion animals

This study was aimed to search and characterize the AmpC and/or ESBL genes of Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa isolated from clinical cases of local livestock and companion animals between 2017 and 2019. A total of eight ceftiofur-resistant E. coli (n= 7) and ceftiofur-resistant K. pneumoniae (n= 1) and seven P. aeruginosa were isolated from different cases in local animals. By combination disc method, six E. coli isolates and one K. pneumoniae isolate were found to be ESBL producers. By combination of the disc method and double disc synergy test, no P. aeruginosa isolates were found as ESBL producers. In the agar disc diffusion test (ADDT) performed with cefoxitin and cefoxitin-boronic, only one E. coli was determined as AmpC producer. In ESBL-producing isolates, only the CTX-M class gene was detected by polymerase chain reaction (PCR) and subsequent sequence analysis revealed CTX-M-3 and CTX-M-15 variants. An AmpC positive E. coli isolate was found to carry plasmidic ampC gene in cmy-2 variant from CIT family. It was observed that P. aeruginosa isolates did not carry the plasmidic ampC gene. After the chromosomal ampC gene of one P. aeruginosa was amplified by PCR and sequenced, R79Q and T105A mutations in the chromosomal ampC gene was revealed. This showed that overproduction of the ampC enzyme is involved in the resistance to β-lactams in P. aeruginosa isolates in the study.

Evaluation of The Antioxidant, Antimicrobial, and Anticancer Activities of Dicliptera bupleuroides Isolated Compounds Using In Vitro and In Silico Studies

Phytochemical investigation of chloroform fraction (DBC) and ethyl acetate fraction (DBE) of D. bupleuroides (Acanthaceae) resulted in the isolation of β-sitosterol (1) from DBC and vanillic acid (2) from DBE, which were first to be isolated from D. bupleuroides. β-Sitosterol (1) exhibited substantial antioxidant activity (IC50 = 198.87 µg/mL), whereas vanillic acid (2) showed significant antioxidant power (IC50 = 92.68 µg/mL) employing 1,1-diphenyl-2-picrylhydrazyl (DPPH*) radical scavenging capacity assay. Both compounds showed pronounced antimicrobial activity using the agar disc diffusion method, particularly against fungi showing MIC values of 0.182 and 0.02 concerning Candida albicans, respectively, and 0.001 mg/mL regarding Penicillium notatum. They revealed considerable antibacterial activity with MIC values ranging between 0.467 and 0.809 mg/mL. Vanillic acid (2) exhibited substantial anticancer potential displaying 48.67% cell viability at a concentration of 100 μg/mL using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-Diphenyl-2H-Tetrazolium Bromide) assay concerning HepG2 cell lines. These results were further consolidated by in silico studies on different enzymes, where vanillic acid displayed a high fitting score in the active pockets of DNA-gyrase, dihydrofolate reductase, aminoglycoside nucleotidyltransferase, and β-lactamase. It also inhibited human cyclin-dependent kinase 2 (CDK-2) and DNA topoisomerase II, as revealed by the in silico studies. ADME/TOPKAT (absorption, distribution, metabolism, excretion, and toxicity) prediction showed that vanillic acid exhibited reasonable pharmacodynamic, pharmacokinetic, and toxicity properties and, thus, could perfectly together with D. bupleuroides crude extract be incorporated in pharmaceutical preparations to counteract cancer and microbial invasion, as well as oxidative stress. Thus, it is concluded that D. bupleroides could be a potential source of therapeutically active compounds, which would be helpful for the discovery of clinically effective and safe drugs.

Occurrence of Leaf Spot Caused by Mycocentrospora acerina on Zhujieshen(Panax japonicus C. A. Mey.) in China

Panax japonicus C. A. Mey., known as Japanese ginseng or “Zhujieshen” in China, is a perennial medicinal herb (family Araliaceae) native to China and is widely grown in many provinces including Hubei, Hunan, and Sichuan. In recent years, cultivation of Japanese ginseng has increased tremendously in China because of its high value. Its root is widely used in traditional Chinese medicine for the treatment of inflammation. In early May 2020, severe necrotic lesions on leaves with 40 to 50 % disease incidences were observed on 3-year-old Japanese ginseng plants in a cultivated field in Xuanen County (30°05′N, 109°83′E), Hubei Province, China. The total area affected by the disease was approximately 30 ha. Initial symptoms showed small, circular, brown, necrotic spots uniformly distributed on leaves. The center of the spots was light tan, surrounded by a dark brown ring and a chlorotic halo. As the disease progressed, multiple lesions merged into large disease spots with visible white fungal hyphae, causing leaf wilting. Ten small pieces (0.1 × 0.1 cm in size) of leaf tissue were removed from the lesion margins, surface-sterilized with 0.5 % sodium hypochlorite for 1 min and 75 % alcohol for 20 s, washed with sterile distilled water three times, dried, and placed on Petri plates with potato dextrose agar (PDA) medium containing 10 µg/ml of ampicillin and incubated at 20 °C for 5 days. Colonies with dense mycelia were initially white and gradually becoming black. The hyphae were septate, branched, and 3 to 7 µm in width. Conidiophores were flexuous, not branched, and produced a single spore. Spores (ranged from 95.4 to 255.5 × 6.2 to 13.5 μm) were elongate, multiseptate, with a long, strongly curved beak (ranged from 25.5 to 95.4 μm), The number of septae ranged from 4 to 13. Clamydospores with smooth or slightly rough wall were spherical to ovoid and averaged 8.5 to 25.4 × 7.2 to 16.5 μm. The six isolates were preliminarily identified as Mycocentrospora acerina (R. Hartig) Deightonbased on the morphological characteristics (Gilchrist et al. 2015). To confirm the identification, isolates ZJS1, ZJS3, and ZJS5 were chosen for DNA sequencing. The internal transcribed spacer (ITS) region of rDNA was amplified using the ITS1 and ITS4 primers (White et al. 1990) and sequenced. The identical sequences of the 491 bp amplicons were deposited in GenBank (accession no. ZJS1, MZ277314; ZJS3, OL333859; and ZJS5, OL333860). BLAST analysis of the sequences showed 100 % identity to M. acerina (MH856114). Moreover, the three isolates were further confirmed as M. acerina by amplifying the large subunit (LSU) of the ribosome gene (accession no. ZJS1, MZ277321; ZJS3, OL333861; and ZJS5, OL333862), as their identical sequences exhibited 99.83 % similarities with M. acerina (MH868490). Isolate ZJS1 was chosen to fulfill Koch’s postulates with 30 healthy 2-year-old P. japonicus grown in plastic pots filled with a sterilized mixture of peat moss and vermiculite (3:1). One leaf of each plant was inoculated with one 5-mm-diameter mycelium-agar disc and placed in a greenhouse at 20 ± 1 °C, with ambient lighting and relative humidity of 85 %. By 5 days after inoculation, all inoculated plants showed symptoms identical to those observed in the field, and no symptoms were observed on control plants. The fungus was reisolated from the inoculated plants and identified as M. acerina using the above method. The experiment was conducted thrice with similar results. To our knowledge, this is the first report of leaf spot caused by M. acerina on Japanese ginseng in China and the world. There is a need to develop effective management measures to reduce the occurrence of this disease.

Pneumococcal carriage and antibiotic susceptibility patterns in mother-baby pairs in a rural community in Eastern Uganda: a cross-sectional study

Background: Pneumococcal carriage predisposes children to pneumonia. Pneumonia poses a significant threat to the lives of children below five years old worldwide, contributing to a high number of hospitalizations and death. Morbidity and morbidity are especially common in children under five and the elderly, although any age group can be affected. This study aimed to estimate pneumococcal carriage and determine antibiotic susceptibility patterns of the pneumococci isolated from mother-baby pairs in Ngora district after the rollout of the pneumococcal vaccine. We hypothesized that high carriage of Streptococcus pneumoniae in mothers leads to carriage in their babies and hence a greater chance of contracting pneumonia. Methods: Consecutive sampling was used to select 152 mother-baby pairs from community visits and those seeking care at the health facility. We collected nasal swabs from both baby and mother for culture and sensitivity testing using Kirby-Bauer’s agar disc diffusion method. Data was also collected from the mothers who consented to take part in the study, using an interviewer-administered questionnaire. Results: This study found that there was a low prevalence of pneumococcal carriage in the mother-baby pair in the Ngora district. Only one mother-baby pair (1/152) was found to be colonized with pneumococci in both mother and baby and the rest of S. pneumoniae colonized either the mother or baby. We also observed high rates of microbial resistance to penicillin, which is the first-line drug for the management of pneumonia in Uganda. Also, high resistance patterns were recorded with chloramphenicol (50%) and tetracycline (50%), whereas the lowest resistance was recorded in clindamycin (17%). Conclusions: The relationship between pneumococcal carriage and immunization status suggests that the pneumococcal vaccine is protective against the pneumococcal carriage. Resistance of S. pneumoniae to commonly used antibiotics was high.

Pneumococcal carriage and antibiotic susceptibility patterns in mother-baby pairs in a rural community in Eastern Uganda: a cross-sectional study

Background: Pneumococcal carriage predisposes children to pneumonia. Pneumonia poses a significant threat to the lives of children below five years old worldwide, contributing to a high number of hospitalizations and death. Morbidity and morbidity are especially common in children under five and the elderly, although any age group can be affected. This study aimed to estimate pneumococcal carriage and determine antibiotic susceptibility patterns of the pneumococci isolated from mother-baby pairs in Ngora district after the rollout of the pneumococcal vaccine. We hypothesized that high carriage of Streptococcus pneumoniae in mothers leads to carriage in their babies and hence a greater chance of contracting pneumonia. Methods: Consecutive sampling was used to select 152 mother-baby pairs from community visits and those seeking care at the health facility. We collected nasal swabs from both baby and mother for culture and sensitivity testing using Kirby-Bauer’s agar disc diffusion method. Results: This study found that there was a low prevalence of pneumococcal carriage in the mother-baby pair in the Ngora district. We also observed high rates of microbial resistance to penicillin, which is the first-line drug for the management of pneumonia in Uganda. Conclusions: The relationship between pneumococcal carriage and immunization status suggests that the pneumococcal vaccine is protective against the pneumococcal carriage. Resistance of S. pneumoniae to commonly used antibiotics was high.