In vitro antiplasmodial and anticancer analyses of endophytic fungal extracts isolated from selected Nigerian medicinal plants.

Ethnomedicinal plants are thought to have better prospects of harboring endophytes that produce natural products with pharmacological activities. This study aimed to investigate the antiplasmodial and anticancer properties of secondary metabolites of endophytic fungi from three medicinal plants. The endophytic fungi included Lasiodiplodia theobromae isolated from Cola acuminata, Curvularia lunata Bv4 isolated from Bambusa vulgaris, and Curvularia lunata Eg7 isolated from Elaeis guineensis. The identification of the fungi was based on the internal transcribed spacer (ITS-rDNA) sequence. The fungi were subjected to solid-state fermentation and the secondary metabolites were extracted with ethyl acetate. In vitro antiplasmodial screening of extracts was performed using the SYBR green I-based fluorescence assay on the chloroquine-resistant Plasmodium falciparum strain DD2. The cytotoxicity of the extracts on human red blood cells and Jurkat (leukemia) cells was assessed using the tetrazolium-based colorimetric MTT assay. Gas chromatography-mass spectrometry (GC-MS) analysis was used to identify the constituents of the fungal extracts. The extract of L. theobromae showed the best antiplasmodial activity against chloroquine-resistant P. falciparum (IC50 = 5.4 µg/mL) and was not harmful to erythrocytes (CC50 > 100 µg/mL). All three fungal extracts showed a weak cytotoxic effect against Jukart cell lines (CC50 > 100 µg/mL). GC-MS analysis of the three endophytic fungal extracts revealed the presence of forty major bioactive compounds, including: oxalic acid, isobutyl nonyl ester, 2,4-di-tert-butylphenol, and hexadecanoic acid, among others. The endophytic fungi from the medicinal plants in this study were promising sources of bioactive compounds that could be further evaluated as novel drugs for the treatment of malaria caused by P. falciparum-resistant strains.

Prevalence of plasmid-mediated quinolone resistance genes and biofilm formation in different species of quinolone-resistant clinical Shigella isolates: a cross-sectional study.

BACKGROUND: The purpose of this study was to look into the presence of plasmid-mediated quinolone resistance (PMQR) genes and biofilm formation in several species of clinical Shigella isolates that were resistant to quinolones. METHODS: The stool samples of 150 patients (younger than 10 years) with diarrhea were collected in this cross-sectional study (November 2020 to December 2021). After cultivation of samples on Hektoen Enteric agar and xylose lysine deoxycholate agar, standard microbiology tests, VITEK 2 system, and polymerase chain reaction (PCR) were utilized to identify Shigella isolates. The broth microdilution method was used to determine antibiotic susceptibility. PMQR genes including qnrA, qnrB, qnrC, qnrD, qnrE, qnrS, qnrVC, qepA, oqxAB, aac(6')-Ib-cr, and crpP and biofilm formation were investigated in quinolone-resistant isolates by PCR and microtiter plate method, respectively. An enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) technique was used to determine the clonal relatedness of quinolone-resistant isolates. RESULTS: A total of 95 Shigella isolates including S. sonnei (53, 55.8%), S. flexneri (39, 41.1%), and S. boydii (3, 3.2%) were identified. The highest resistance rates of the isolates were against ampicillin (92.6%, n = 88/95). Overall, 42 of 95 (44.2%) isolates were simultaneously resistant against two or more quinolones including 26 (61.9%) S. sonnei and 16 (38.1%) S. flexneri. All isolates were multidrug-resistant (resistance to more than 3 antibiotics). The occurrence of PMQR genes was as follows: qnrS (52.4%), qnrA and aac(6')-Ib-cr (33.3%), and qnrB (19.0%). The prevalence in species was as follows: 61.5% and 37.5% (qnrS), 19.2% and 56.3% (qnrA), 38.5% and 25.0 (aac(6')-Ib-cr), and 19.2% and 18.8% (qnrB) for S. sonnei and S. flexneri, respectively. The other PMQR genes were not detected. In total, 52.8% (28/53) of quinolone-susceptible and 64.3% (27/42) of quinolone-resistant isolates were biofilm producers. Biofilm formation was not significantly different between quinolone-resistant and quinolone-susceptible isolates (P-value = 0.299). Quinolone-resistant isolates showed a high genetic diversity according to the ERIC-PCR. CONCLUSION: It seems that qnrS, qnrA, and aac(6')-Ib-cr play a significant role in the quinolone resistance among Shigella isolates in our region. Also the quinolone-resistant S. flexneri and S. sonnei isolates had a high genetic diversity. Hence, antibiotic therapy needs to be routinely revised based on the surveillance findings.

In vivo and in vitro efficacy of the ithmid kohl/zinc-oxide nanoparticles, ithmid kohl/Aloe vera, and zinc-oxide nanoparticles/Aloe vera for the treatment of bacterial endophthalmitis.

The aim of this study was to investigate the efficacy of the ithmid kohl/zinc-oxide nanoparticles (ZnONPs), ithmid kohl/Aloe vera, and ZnONPs/Aloe vera in the treatment of bacterial endophthalmitis. The endophthalmitis model was prepared by contaminating both eyes of 24 healthy adult male albino rabbits with a clinical isolate of Klebsiella pneumoniae. The animals were randomly divided into eight groups (A-H) according to the treatment. Group A received 1 ml of ithmid kohl/ZnONPs ointment, group B received 1 ml of ithmid kohl/Aloe vera gel ointment, group C received 1 ml of ZnONPs/Aloe vera gel ointment, and groups D, E, and F were treated with 1 ml of ithmid kohl solution (0.5 g/ml in distilled water), 1 ml of ZnONPs (0.5 g/ml) colloidal dispersion, and 1 ml of Aloe vera gel, respectively. Group G received 100 µl of a tetracycline antibiotic solution (final concentration: 16 µg/ml), and group H received sterile distilled water (no treatment). In vitro antibacterial activity was evaluated against K. pneumoniae using the agar well diffusion. The combination of ithmid kohl/ZnONPs was the most effective formulation for treating endophthalmitis model in infected rabbits within 2 days. In vitro antibacterial assay confirmed the potential of the ithmid kohl/ZnONPs formulation, which had the largest zone of inhibition (31 mm) among the compounds tested. The preparation of the ithmid kohl/ZnONPs formulation and its in vivo experiment in albino rabbits for the treatment of bacterial endophthalmitis was an innovative approach that has shown promise and may potentially serve as a viable alternative in clinical practice.

Antibacterial, Antibiofilm, and Antioxidant Activities of Aqueous Crude Gymnema inodorum Leaf Extract against Vancomycin-Resistant Enterococcus faecium.

Vancomycin-resistant Enterococcus faecium (VREF) causes nosocomial infections with high mortality and morbidity rates. This study aimed to evaluate the antibacterial and antibiofilm activities of aqueous crude Gymnema inodorum leaf extract (GIE) against the VREF ATCC 700221 strain. The antimicrobial activity of GIE against VREF was performed using disk diffusion and broth microdilution. The antibiofilm activities were evaluated using the crystal violet staining assay. The antioxidant potential was evaluated. Preliminary screening of the antimicrobial activity of 50 and 100 µg/disk of GIE against VREF revealed inhibition zones of 8.33 ± 0.58 mm and 8.67 ± 0.29 mm, respectively. Additionally, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values against VREF were 125 and ≥ 250 mg/mL, respectively. SEM analysis showed that treatment with GIE caused morphological changes, including incomplete cell division, damaged cell walls, and cell content leakage, suggesting a disruption of bacterial cells. GIE also inhibited and eradicated biofilms formed by VREF. The extract exhibited antioxidant activities in the DPPH and ABTS assays. While GIE shows potential as an antibacterial and antibiofilm agent, further studies are necessary to fully understand the underlying mechanisms and optimize its use for therapeutic applications.

Lyophilized cell-free supernatants of Limosilactobacillus fermentum T0701 exhibited antibacterial activity against Helicobacter pylori.

Helicobacter pylori is a prominent gastrointestinal pathogen associated with various gastrointestinal illnesses. It presents substantial health risks due to its antibiotic resistance. Therefore, it is crucial to identify alternative treatments for H. pylori infections. Limosilactobacillus spp exhibit probiotic properties with beneficial effects in humans; however, the mechanisms by which it counteracts H. pylori infection are unknown. This study aimed to evaluate the potential of Limosilactobacillus fermentum T0701 lyophilized cell-free supernatants (LCFS) against H. pylori. The LCFS has varying antimicrobial activities, with inhibition zones of up to 10.67 mm. The minimum inhibitory concentration and minimum bacterial concentration of LCFS are 6.25-25.00 mg/mL and 6.25 mg/mL to > 50.00 mg/mL, respectively, indicating its capability to inhibit H. pylori. There is morphological damage observed in H. pylori treated with LCFS. Additionally, H. pylori adhesion to AGS cells (human gastric adenocarcinoma epithelial cells) reduces by 74.23%, highlighting the LCFS role in preventing bacterial colonization. Moreover, LCFS exhibits no cytotoxicity or morphological changes in AGS cells, and with no detected virulence or antimicrobial resistance genes, further supporting its safety profile. L. fermentum T0701 LCFS shows promise as a safe and effective non-toxic agent against H. pylori, with the potential to prevent gastric colonization.

Antibiotic resistance and genomic characterization of Mycobacterium abscessus complex isolates from patients with pulmonary tuberculosis in Iran: A multi-center study (2010-2021).

One hundred and eighteen sputum specimens suspected of Mycobacterium abscessus infection were collected. Species level identification of M. abscessus was performed by rpoB sequencing. Clonality analysis was done by multilocus sequence typing (MLST) for M. abscessus. Antibiotic susceptibility testing was performed for clarithromycin, amikacin, ciprofloxacin and moxifloxacin. Altogether 128 isolates were obtained and were subjected to rpoB gene sequencing for definite identification. Among them 59 were identified as M. abscessus, and these included 22 (37.28%) isolates of M. abscessus subsp. abscessus, 22 (37.28%) isolates of M. abscessus subsp. massiliense, and 15 (25.42%) isolates of M. abscessus subsp. bolletii. All 59 M. abscessus complex isolates were analyzed by MLST in this study. Certain sequence types (STs) were identified among the 59 isolates and were specific for each subspecies. Two STs (ST40 and ST33) were specific to M. abscessus subsp. abscessus, one ST (ST20) was specific to M. abscessus subsp. bolletii, and one ST (ST15) was specific to M. abscessus subsp. massiliense. In antibiotic resistance, clarithromycin susceptibility testing of 22 M. abscessus subsp. abscessus strains detected 15 (68.18%) resistant strains, while among 22 M. abscessus subsp. massiliense strains 5 (22.72%) exhibited resistance, and among 15 M. abscessus subsp. bolletii 8 (53.33%) were resistant. Our study revealed a significant level of antibiotic resistance in isolates of the M. abscessus complex.

A computational investigation of galactopyranoside esters as antimicrobial agents through antiviral, molecular docking, molecular dynamics, pharmacokinetics, and bioactivity prediction.

One of the most common viral infections worldwide is the Human Papilloma Virus (HPV) which has been linked to cancer and other diseases in many countries. Monosaccharide esters are significant in the field of carbohydrate chemistry because they are efficient in the synthesis of pharmacologically active compounds. Therefore, the present study aimed to perform thermodynamic, molecular docking and molecular dynamics study of a series of previously designed monosaccharaides, methyl ß-d-galactopyranoside (MGP, 1) esters (2-10) with along with their physicochemical and pharmacokinetic properties. We have optimized the MGP esters employing the DFT study at the B3LYP/6-311 + G (d,p) level of theory. The subsequent analysis also investigated the electronic energies, enthalpies, entropies, polarizability, and natural bond orbital (NBO) of these modified esters. Then, MGP esters were docked into CTX-M-15 extended-spectrum beta-lactamase from Escherichia coli (PDB: 4HBT) and E2 DNA-binding domain from human papillomavirus type 31 (PDB: 1A7G), and the results revealed that most of the esters can efficiently bind to the target. Desmond was used to doing molecular dynamics simulations at 200 ns in addition to molecular docking to look at the binding conformational stability of the protein-ligand complex. Based on RMSD and RMSF, it was determined that the stability of the protein-ligand combination was maintained during the whole 200 ns simulations for all compounds. Finally, a pharmacokinetic study suggests that modified esters of MGP exhibited better pharmacokinetic characteristics and were less hazardous than the parent drug. This work demonstrated that potential MGP esters can efficiently bind to 4HBT and 1A7G proteins and opened avenues for the development of newer antimicrobial agents that can target dangerous pathogens.Communicated by Ramaswamy H. Sarma.

Occurrence of some common carbapenemase genes in carbapenem-resistant Klebsiella pneumoniae isolates collected from clinical samples in Tabriz, northwestern Iran.

OBJECTIVES: This study aimed to evaluate the antibiotic resistance patterns and prevalence of carbapenemase genes in Klebsiella pneumoniae isolates in different clinical samples from Tabriz city, northwestern Iran. RESULTS: This cross-sectional study was conducted in the Department of Microbiology, Islamic Azad University, Ahar Branch, Iran, in 2020. K. pneumoniae isolates were collected from different clinical samples, including blood, wounds, sputum, and urine. The isolates were identified using a series of standard bacteriological tests. Antibiotic resistance was determined by the disc diffusion method. The presence of blaVIM, blaNDM, blaKPC, blaOXA, and blaIMP genes were screened by polymerase chain reaction (PCR). A total of 100 non-duplicated K. pneumoniae isolates were collected from 57 urine samples, 27 blood samples, 13 wound samples, and 3 sputum samples. Overall, 70.0% of the samples were from inpatients, while 30.0% were from outpatients. The most resistance rate was related to ampicillin (94.0%), while the lowest resistance rate was related to imipenem (18.0%) and meropenem (20.0%). Overall, 25.0% of the isolates were carbapenem-resistant, of which 13.0% were resistant to both imipenem and meropenem. The PCR showed the total prevalence of 23.0% for carbapenemase genes, including 18.0% for blaKPC, 3.0% for blaVIM, 1.0% for blaIMP, and 1.0% for blaOXA gene. The blaNDM gene was not detected in any isolate. The prevalence of carbapenemase-producing K. pneumoniae isolates was relatively lower in northwestern Iran than in other regions of the country. However, special attention should be paid to the proper use of antibiotics, particularly carbapenems, to prevent further spread of antibiotic resistance and its related genes.

A study on the effect of natural products against the transmission of B.1.1.529 Omicron.

BACKGROUND: The recent outbreak of the Coronavirus pandemic resulted in a successful vaccination program launched by the World Health Organization. However, a large population is still unvaccinated, leading to the emergence of mutated strains like alpha, beta, delta, and B.1.1.529 (Omicron). Recent reports from the World Health Organization raised concerns about the Omicron variant, which emerged in South Africa during a surge in COVID-19 cases in November 2021. Vaccines are not proven completely effective or safe against Omicron, leading to clinical trials for combating infection by the mutated virus. The absence of suitable pharmaceuticals has led scientists and clinicians to search for alternative and supplementary therapies, including dietary patterns, to reduce the effect of mutated strains. MAIN BODY: This review analyzed Coronavirus aetiology, epidemiology, and natural products for combating Omicron. Although the literature search did not include keywords related to in silico or computational research, in silico investigations were emphasized in this study. Molecular docking was implemented to compare the interaction between natural products and Chloroquine with the ACE2 receptor protein amino acid residues of Omicron. The global Omicron infection proceeding SARS-CoV-2 vaccination was also elucidated. The docking results suggest that DGCG may bind to the ACE2 receptor three times more effectively than standard chloroquine. CONCLUSION: The emergence of the Omicron variant has highlighted the need for alternative therapies to reduce the impact of mutated strains. The current review suggests that natural products such as DGCG may be effective in binding to the ACE2 receptor and combating the Omicron variant, however, further research is required to validate the results of this study and explore the potential of natural products to mitigate COVID-19.

The global prevalence of gastric cancer in Helicobacter pylori-infected individuals: a systematic review and meta-analysis.

BACKGROUND: Helicobacter pylori is a gastrointestinal pathogen that infects around half of the world's population. H. pylori infection is the most severe known risk factor for gastric cancer (GC), which is the second highest cause of cancer-related deaths globally. We conducted a systematic review and meta-analysis to assess the global prevalence of GC in H. pylori-infected individuals. METHODS: We performed a systematic search of the PubMed, Web of Science, and Embase databases for studies of the prevalence of GC in H. pylori-infected individuals published from 1 January 2011 to 20 April 2021. Metaprop package were used to calculate the pooled prevalence with 95% confidence interval. Random-effects model was applied to estimate the pooled prevalence. We also quantified it with the I2 index. Based on the Higgins classification approach, I2 values above 0.7 were determined as high heterogeneity. RESULTS: Among 17,438 reports screened, we assessed 1053 full-text articles for eligibility; 149 were included in the final analysis, comprising data from 32 countries. The highest and lowest prevalence was observed in America (pooled prevalence: 18.06%; 95% CI: 16.48 - 19.63; I2: 98.84%) and Africa (pooled prevalence: 9.52%; 95% CI: 5.92 - 13.12; I2: 88.39%). Among individual countries, Japan had the highest pooled prevalence of GC in H. pylori positive patients (Prevalence: 90.90%:95% CI: 83.61-95.14), whereas Sweden had the lowest prevalence (Prevalence: 0.07%; 95% CI: 0.06-0.09). The highest and lowest prevalence was observed in prospective case series (pooled prevalence: 23.13%; 95% CI: 20.41 - 25.85; I2: 97.70%) and retrospective cohort (pooled prevalence: 1.17%; 95% CI: 0.55 - 1.78; I 2: 0.10%). CONCLUSIONS: H. pylori infection in GC patients varied between regions in this systematic review and meta-analysis. We observed that large amounts of GCs in developed countries are associated with H. pylori. Using these data, regional initiatives can be taken to prevent and eradicate H. pylori worldwide, thus reducing its complications.

Computational design of medicinal compounds to inhibit RBD-hACE2 interaction in the Omicron variant: unveiling a vulnerable target site.

The COVID-19 pandemic, caused by SARS-CoV-2, has globally affected both human health and economy. Several variants with a high potential for reinfection and the ability to evade immunity were detected shortly after the initial reported case of COVID-19. A total of 30 mutations in the spike protein (S) have been reported in the SARS-CoV-2 (BA.2) variant in India and South Africa, while half of these mutations are in the receptor-binding domain and have spread rapidly throughout the world. Drug repurposing offers potential advantages over the discovery of novel drugs, and one is that it can be delivered quickly without lengthy assessments and time-consuming clinical trials. In this study, computational drug design, such as pharmacophore-based virtual screening and MD simulation has been concentrated, in order to find a novel small molecular inhibitor that prevents hACE2 from binding to the receptor binding domain (RBD). three medicinal compound databases: North-East African, North African, and East African were screened and carried out a multi-step screening approach that identified three compounds, which are thymoquinol 2-O-beta-glucopyranoside (C1), lanneaflavonol (C2), and naringenin-4'-methoxy-7-O-Alpha-L-rhamnoside (C3), with excellent anti-viral properties against the RBD of the omicron variant. Furthermore, PAIN assay interference, computation bioactivity prediction, binding free energy, and dissociation constant were used to validate the top hits, which indicated good antiviral activity. The three compounds that were found may be useful against COVID-19, though more research is required. These findings could aid the development of novel therapeutic drugs against the emerging Omicron variant of SARS-CoV-2.

Molecular evaluation of aminoglycosides resistance and biofilm formation in Klebsiella pneumoniae clinical isolates: A cross-sectional study.

Background and Aims: Resistance to antibiotics and the capability to develop biofilm as two main virulent determinants of Klebsiella pneumoniae have important role in infection persistence. The aim of the study was to evaluate the association between the prevalence of aminoglycoside resistance and virulence genes and biofilm formation capacity in K. pneumoniae strains isolated from hospitalized patients in South-West of Iran. Methods: A total of 114 non-duplicate clinical isolates of K. pneumoniae collected from Ahvaz teaching hospitals. Identification of species was performed by biochemical tests and then confirmed by polymerase chain reaction (PCR) of rpoB gene. The susceptibility to antibiotics was determined by Kirby-Bauer disk diffusion method. Biofilm formation was assessed by microtiter plate method. Finally, PCR was conducted to detect virulence gene determinants including fimbrial genes, aminoglycoside modifying enzymes- and 16S rRNA methylase (RMTase) genes. Results: Totally, all collected strains were carbapenem resistant and showed multidrug- and extensively drug-resistance phenotype (75% and 25%, respectively). Seventy-one percent (n = 81) of isolates were non-susceptible to aminoglycosides. Among aminoglycoside antibiotics, K. pneumoniae isolates showed the highest and lowest resistance rates to tobramycin (71%) and the amikacin (25%), respectively. All biofilm producer strains were positive for the presence virulence determinants including ecpA, fimA, mrkD, and mrkA. Of 81 aminoglycosides non-susceptible isolates 33% were positive for the presence ant (2″)-Ia as the most prevalent gene followed by aac (3')-IIa and armA (27%), aac (6')-Ib (18%), and aph (3')-Ia (15%). Conclusion: K. pneumoniae isolates showed the highest and the lowest aminoglycoside resistance rates to tobramycin and amikacin, respectively. Majority of isolates were biofilm producers and there was significant association between antibiotic resistance pattern and the strength of biofilm production. The ant(2″)-Ia, aac (3')-IIa, and armA genes in aminoglycoside-resistant isolates.

Seroprevalence of antibodies to herpes simplex virus 1 and 2 in patients with HIV positive from Ebonyi State, Nigeria: a cross-sectional study.

OBJECTIVES: To assess the seroprevalence of herpes simplex virus (HSV) types 1 and 2 in patients infected with HIV in Nigeria. DESIGN: Cross-sectional design from January to June 2019. SETTING: Federal Teaching Hospital, Ebonyi State, Nigeria. PARTICIPANTS: A total of 276 patients with HIV were analysed using ELISA method for the presence of HSV-1 and HSV-2 specific IgG antibodies. OUTCOMES: Fisher's exact test was used to determine the association between the seroprevalence of HSV and demographic variables (statistically significant=p value ≤0.05). RESULTS: Totally, 212 (76.8%) and 155 (56.2%) patients with HIV were seropositive for HSV-1 and HSV-2 IgG antibodies, respectively. The seroprevalence of HSV-1 was significantly higher than the HSV-2 in patients with HIV (p value <0.0001). HSV-1 and HSV-2 seroprevalence were higher in patients aged more than 30 years. The seroprevalence of HSV-1 was significantly higher (p=0.01) in females (82.4%, 131/159) than males (69.2%, 81/117), but there was no significant difference in seroprevalence of HSV-2 in females (57.9%, 92/159) compared with males (53.8%, 63/117) (p=0.51). Professional drivers had a higher seroprevalence of HSV-1 and HSV-2 and there was a significant association between the occupation and the HSV-1 and HSV-2 seropositivity (p>0.05). The seroprevalence of HSV-1 was significantly higher in the singles (87.4%, 90/103) than the married patients with HIV (p=0.001). However, HSV-2 seroprevalence was significantly higher in the married patients with HIV (63.6%, 110/173) (p=0.001). CONCLUSIONS: Prevalence of 76.8% for HSV-1 and 56.2% for HSV-2 among patients with HIV was seen. The HSV-1 was significantly higher in the singles while HSV-2 seroprevalence was significantly higher in the married patients with HIV with HSV-1 and HSV-2 coinfection rate of 7.6%. This study became very imperative to provide an important insight into the hidden dynamics of HSV infections.

The prevalence of clarithromycin-resistant Helicobacter pylori isolates: a systematic review and meta-analysis.

Background: Knowledge of global clarithromycin (CLA)-resistant rates of Helicobacter pylori (H. pylori) is crucial for decision of the most appropriate eradication therapies with good clinical outcomes. Therefore, this review and meta-analysis aimed to evaluate the global prevalence of the CLA resistance in H. pylori to provide some guidance for selecting the first-line antibiotics. Method: A comprehensive search was performed for relevant literature until April 2021 in PubMed, Embase, and Web of Science databases. Freeman-Tukey double arcsine transformation was performed to estimate the weighted pooled prevalence of resistance. Results: The meta-analysis included 248 articles. The prevalence of CLA-resistant H. pylori was 27.53% (95% CI [25.41-29.69]). The heterogeneity between reports was significant (I2 = 97.80%, P < 0.01). The resistance rate increased from 24.28% in 2010-2017 to 32.14% in 2018-2021 (P < 0.01). Iran, with 38 articles, has the most report. Nevertheless, Switzerland, Portugal, and Israel had the highest resistance rates (67.16%, 48.11%, and 46.12%, respectively). The heterogeneity between the continents and the antimicrobial susceptibility methods also interpreted standard guidelines and breakpoints was insignificant (P > 0.05). Conclusion: Overall CLA resistance rate was 27.53%, worldwide. The difference in CLA resistance rate among the included studies can be due to several reasons such as differences in antibiotic prescription rates in various geographic areas, use of different breakpoints or inaccurate criteria in performed studies, and the emergence of multidrug-resistant (MDR) strains.

Biofilm Formation Capacity and Presence of Virulence Determinants among Enterococcus Species from Milk and Raw Milk Cheeses.

Bacterial biofilm is one of the major hazards facing the food industry. Biofilm-forming ability is one of the most important virulence properties of enterococci. The genus Enterococcus includes pathogenic, spoilage, and pro-technological bacteria. The presence of enterococci in milk and dairy products is usually associated with inadequate hygiene practices. The study examined the isolates' capacity for biofilm formation and identification of the genetic determinants of its formation among 85 Enterococcus strains isolated from raw milk (n = 49) and soft-ripened cheeses made from unpasteurized milk (n = 36). E. faecalis and E. faecium were the dominant species. The obtained results showed that 41.4% isolates from milk and 50.0% isolates from cheeses were able to form biofilm. All of the isolates analyzed had at least one of the studied genes. As regards the isolates from raw milk, the most prevalent gene was the gelE (85.6%), followed by the asa1 (66.7%). None of the isolates from cheeses showed the presence of cylA and sprE. The most prevalent gene among the strains from this source was the epbC (94.4%), followed by the gelE (88.9%). In isolates from both sources, the presence of proteins from the Fsr group was noted the least frequently. Nevertheless, results showed that were no significant differences between the biofilm-producing Enterococcus spp. and non-biofilm-producing isolates in term of occurrences of tested virulence genes. The ability to produce a biofilm by enterococci isolated from raw milk or ready-to-eat products emphasizes the need for continuous monitoring of the mechanisms of microbial adhesion.

Co-existence of extended-spectrum ß-lactamases blaCTX-M-9 and blaCTX-M-15 genes in Salmonella species isolated from febrile and diarrhoeagenic patients in Lagos, Nigeria: a cross-sectional study.

BACKGROUND: Resistance to different antimicrobial classes by Salmonella species has generated a global public health concern. The spread of extended-spectrum ß-lactamases (ESBLs) blaCTX gene variants is also increasing. This study aimed to investigate the antibiotic resistance and the carriage of blaCTX-M-9 and blaCTX-M-15 as well as the quinolone resistance gene (qnrB19) among Salmonella species from hospitalised patients in Lagos, Nigeria. METHODS: In this cross-sectional study from April 2021 to August 2021, a total of 508 samples were collected from hospitalised patients. The samples were subjected to standard microbiological investigation. All the isolates were identified using API 20E kits and real-time polymerase chain reaction (RT-PCR). The in vitro antibiotic susceptibility testing (AST) was investigated using the disk diffusion method. Detection of antibiotic resistance and virulence gene makers was conducted using RT-PCR. RESULTS: In total, 24 Salmonella species were identified. All the isolates were non-typhoidal Salmonella isolates. None of the isolates screened was S. Typhi and S. Paratyphi. Most of the isolates were susceptible to imipenem, ciprofloxacin, ofloxacin and gentamycin, while a high level of resistance to all cephalosporins, penicillin, and some carbapenems was observed. In total, 79.2% (19/24) of the Salmonella isolates harboured the blaCTX-M variant including 54.2% (13/24) blaCTX-M-9 and 12.5% (3/24) blaCTX-M-15, while co-habitation of blaCTX-M-9 and blaCTX-M-15 was observed in 12.5% (3/24) of the isolates, respectively. None of the isolates harboured quinolone-resistant qnrB19 gene and virulence gene stn. However, invA gene was present in 66.7% (16/24) of all isolates. CONCLUSIONS: This study is considered the first report of blaCTX-M-9 and blaCTX-M-15 variants in Salmonella species in Nigeria. The continued existence of cefotaximase (CTX-M)-producing Salmonella within our environment calls for the prudent use of cephalosporins.

Bacterial profiles and their antibiotic resistance background in superinfections caused by multidrug-resistant bacteria among COVID-19 ICU patients from southwest Iran.

This study investigated the bacterial causes of superinfections and their antibiotic resistance pattern in severe coronavirus disease 2019 (COVID-19) patients admitted to the intensive care unit (ICU) of Razi Hospital in Ahvaz, southwest Iran. In this cross-sectional study, endotracheal tube (ETT) secretion samples of 77 intubated COVID-19 patients, confirmed by reverse transcription-quantitative polymerase chain reaction, were investigated by standard microbiology test and analytical profile index kit. Antibiotic susceptibility testing was performed by disc diffusion. The presence of Haemophilus influenzae and Mycoplasma pneumoniae was investigated by the polymerase chain reaction (PCR). Using culture and PCR methods, 56 (72.7%) of the 77 COVID-19 patients (mean age of 55 years, 29 male and 27 female) had superinfections. Using culture, 67 isolates including 29 (43.2%) Gram-positive and 38 (56.7%) Gram-negative bacteria (GNB) were identified from 49 COVID-19 patients. The GNB were more predominant than the Gram-positive pathogens. Klebsiella pneumoniae (28.4%, n = 19/67) was the most common isolate followed by Staphylococcus aureus (22.4%, n = 15/67). Using PCR, 10.4% (8/77) and 11.7% (9/77) of ETT secretion specimens had H. influenzae and M. pneumoniae amplicons, respectively. Gram-positive and Gram-negative isolates showed high resistance rates (>70.0%) to majority of the tested antibiotics including fluoroquinolone, carbapenems, and cephalosporins and 68.7% (46/67) of isolates were multidrug-resistant (MDR). This study showed a high frequency rate of superinfections by MDR bacteria among COVID-19 patients in southwest Iran. The prevention of long-term consequences caused by COVID-19, demands continuous antibiotic surveillance particularly in management of bacterial superinfections.

Beta-lactamase determinants and molecular typing of carbapenem-resistant classic and hypervirulent Klebsiella pneumoniae clinical isolates from southwest of Iran.

This study investigated the molecular epidemiology of carbapenem-resistant classic Klebsiella pneumoniae (CR-cKp) and carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKp) isolates in southwestern Iran. From 2019 to 2021, 136 (88.9%) cKp and 17 (11.1%) hvKp isolates were identified using biochemical tests and polymerase chain reaction (PCR). Antibiotic resistance, beta-lactamases, and clonal relatedness of carbapenem-resistant isolates were investigated using disk diffusion, PCR, and enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR), respectively. The different markers of hvKp isolates were as follows: string test (35.3%, n = 6/17), magA (11.8%, n = 2/17), rmpA (11.8%, n = 2/17), rmpA2 (52.9%, n = 9/17), iucA (52.9%, n = 9/17), and peg344 (35.3%, n = 6/17). Also, 55.1% (n = 75/136) of cKp and 47.1% (n = 8/17) of hvKp isolates were CR-cKp and CR-hvKp, respectively. All CR-hvKp (100.0%, n = 8) isolates were MDR. Colistin, tetracycline, and tigecycline were the most effective antibiotics. The occurrence of beta-lactamase genes in 75 CR-cKp and 8 CR-hvKp isolates was as follows: bla NDM (41.3, 25.0%), bla IMP (4.0, 0.0%), bla VIM (8.0, 0.0%), bla GES (14.7, 25.0%), bla OXA-48-like (20.0, 0.0%), bla CTX-M (26.7, 12.5%), bla SHV (24.0, 12.5%), bla TEM (10.7, 0.0%), bla FOX (6.7, 0.0%), bla DHA (6.7, 0.0%), bla CMY (5.3, 0.0%), bla LAT (12.0, 0.0%), and bla ACT (8.0, 0.0%). ERIC-PCR showed a high diversity among isolates. In this study, the occurrence of MDR CR-hvKp isolates harboring bla NDM and bla GES was detected for the first time in southwestern Iran. To prevent the spread of CR-hvKp and reduce selection pressure, long-term surveillance and more effective treatment strategies should be implemented.

Synergistic effects of silybin and curcumin on virulence and carbapenemase genes expression in multidrug resistant Klebsiella oxytoca.

OBJECTIVE: Silybin and curcumin have potential antimicrobial effects. This study aimed to evaluate the synergistic antimicrobial effects of silybin and curcumin on virulence and carbapenemase genes expression among multidrug-resistant (MDR) Klebsiella oxytoca. RESULTS: A total of 70 MDR K. oxytoca (carrying blaIMP and blaOXA-48-like genes) were included. The antibiotic susceptibility and biofilm production of isolates were determined. The silybin and curcumin at concentrations 10-500 mg/mL alone and in combination were exposed to bacterial isolates in Mueller Hinton broth medium for 24 h. The expression of blaIMP, blaOXA-48-like, mrkA, pilQ, matB and fimA genes was evaluated using quantitative real-time polymerase chain reaction (qRT-PCR). The mean minimum inhibitory concentration (MIC) of curcumin and silybin were 250 mg/mL and 500 mg/mL, respectively. The anti-virulent effect of 100 mg/mL of silybin and curcumin was shown by significant reduction in the expression of fimA (2.1-fold, P < 0.0001) and mrkA (2.1 fold, P < 0.0001) genes. Moreover, these compounds significantly decreased the expression of blaIMP1 (3.2-fold, P < 0.0001) gene. Notably, there was no significant effect on pilQ, matB and blaOXA-48-like genes. The results showed that silybin and curcumin can be candidate as natural way for control the MDR virulent strains of K. oxytoca.

Intimin (eae) and virulence membrane protein pagC genes are associated with biofilm formation and multidrug resistance in Escherichia coli and Salmonella enterica isolates from calves with diarrhea.

OBJECTIVES: This study aimed to evaluate the association of the intimin (eae) and pagC genes with biofilm formation and multidrug resistance (MDR) phenotype in Escherichia coli and Salmonella enterica collected from calves with diarrhea. RESULTS: Fecal samples (n: 150) were collected from calves with diarrhea. Of 150 fecal samples, 122 (81.3%) were culture positive and 115/122 (94.2%) were Gram-negative bacteria. Among them, E. coli (n = 64/115, 55.6%) was the most common isolate followed by S. enterica (n = 41/115, 35.6%). Also, 10 (8.6%) isolates were other Enterobacteriaceae bacteria including Klebsiella and Proteus species. Eighty-nine isolates (77.4%) from calf diarrhea, including 52 (81.3%) E. coli and 37 (90.2%) S. enterica were MDR. The eae and pagC genes were detected in 33 (51.5%) E. coli and 28 (68.3%) S. enterica isolates, respectively. There was a strong association between these genes and biofilm formation and MDR phenotype (P-value = 0.000). All E. coli isolates carrying the eae gene were biofilm producers and MDR. Also, all pagC-positive S. enterica isolates were MDR and 25 (89.3%) isolates of them produced biofilm.