Disc Diffusion Method Research Articles

Preparation and characterization of Ea-AgNPs-Si nanocomposite: investigating it as a poultry reformer, pathogen suppressor, sprouting catalyst and adsorbent

This study synthesizes nano composite (Ea-AgNPs-Si) using Euphorbia antisyphilitica(Ea), employing it as a poultry reformer, sorptive material, pathogen suppressor and sprouting catalyst. Characterization involved XRD, SEM, TEM, Zetasizer, UV-Visible and FT-IR techniques. Ea-AgNPs-Si adopted a face centered cubic arrangement with average crystalline size of 20.34 nm. Zeta potential assessed stability. PDI value of Ea-AgNPs-Si nanocomposite is 1 indicating the polydisperse distribution. SEM revealed flower shape (Ea-AgNPs-Si), ranging 70-100 nm in diameter. The disc diffusion method reveals that EaAgNPs-Si exhibits potent antimicrobial activity at 60 µl against Staphylococcus aureus, Actinomycetes, Escherichia coli, Klebsiella pneumonia and Pseudomonas aeruginosa, attributed to its deep diffusion and release of silver ions and silica. It is unequivocally evident from the data that Langmuir isotherm and Pseudo II order model provides a superior fit approaching R2 value as 0.9972, 0.9461, 0.916, 0.9827, 0.9455 and 0.9534 for LA(I), LA(II), LA(III) describing monolayer chemisorption onto surfaces with uniform adsorption energies than Freundlich, Tempkin and BET models, which is synonymous with the results obtained from R2011a Matlab neuro solution. Through final germination (FG) we concluded that among 130 corriandrum seeds sown,109 sprouted in 20 days. Higher germination index (GI) T2>T4>T1>T3> expedited that Ea-AgNPs-Si shall be used as a nutrient to boost the growth of crops. Ordinarily, it necessitates a span of 45 days for a single batch to attain harvest readiness; however, through our efforts, we have accomplished this feat in a mere 20 days. Henceforth, Ea-AgNPs-Si shall be employed as a Poultry Reformer, Pathogen Suppressor, Sprouting Catalyst and Adsorbent.

Occurrence and antimicrobial resistance of Salmonella isolates in farrow-to-finish pig farms in Bulgaria

Salmonella spp. is an important zoonotic and foodborne pathogen. It is spread worldwide and represents a public health risk. Pigs are a significant reservoir and are frequently subclinical carriers. The aim of this study was to detect the occurrence and antimicrobial resistance of Salmonella isolates being the five most important for public health Salmonella serovars in fattening pigs in Bulgaria. The isolation of Salmonella spp. was carried out according to EN ISO 6579-1 for the detection of Salmonella bacteria in feces and Salmonella serotyping following the Kauffmann-White scheme. All confirmed S. enterica isolates were analysed by the disk-diffusion method for susceptibility to 14 antimicrobials. Salmonella enterica was detected in 13 out of 32 tested farms in Bulgaria. The overall percentage of Salmonella positive pooled fecal samples was 6.8% (43 of 630 samples). The highest occurrence was present in fattening pigs aged between 121-180 days (16.3%; 20/123), followed by dry sows (6.5%; 4/62) and gilts (4.8%; 12/248). About 75% of the isolated strains belonged to three serotypes: Salmonella Infantis (41.9%), Salmonella Give (16.3%) and Salmonella Typhimurium monophasic (16.3%). All the tested isolates were resistant to Tilmicosin (100%), 88.4% to Ampicillin, followed by 69.8% to Tiamulin, 25.6% to Amoxicillin and Chlortetracycline. Multidrug resistance was recorded in 62.8 % of the tested strains. This study reports data regarding the circulation of the most important for public health five Salmonella serovars (S. Enteritidis, S. Typhimurium, S. Typhimurium monophasic, S. Infantis and S. Derby) in farrow-to-finish pig farms in Bulgaria and represent 74.4% of the total Salmonella spp. isolates. This phenomenon has critical effects for the health of consumers and therefore represents a key “one health” issue.

Genetic diversity, virulence profiles, and antimicrobial resistance of Salmonella enterica serovar Typhi isolated from typhoid fever patients in Baghdad, Iraq

Typhoid fever is an important health issue in developing countries, and the pathogenicity of Salmonella enterica serovar Typhi (S. ser. Typhi) depends on the presence of different virulence factors. Therefore, this study aimed to investigate the spread of virulence genes among S. Typhi isolates from patients with typhoid fever in Baghdad, Iraq. Sixty S. Typhi isolates were collected from several hospitals in Baghdad and identified using VITEK-II and confirmed by polymerase chain reaction (PCR) to detect the 16S rRNA gene. After testing their susceptibility to different antimicrobials (via the disk diffusion method), we found the highest resistance rates (100 %) were to ampicillin, piperacillin, cefotaxime, and ceftriaxone. The highest sensitivity rates (100 %) were to ertapenem, imipenem, meropenem, and sulfamethoxazole/trimethoprim. The presence of genes encoding for virulence in S. Typhi isolates was tested by conventional PCR. The results showed that out of 60 isolates, 59 (98.3 %), 59 (98.3 %), 58 (96.7 %), and 60 (100 %) were positive for viaB, staA, cdtB, and orfL genes, respectively. The sequencing of PCR products (viaB, staA, cdtB, and orfL genes) was carried out at the Macrogen Company (Seoul, Korea). The sequences were compared with nucleotide sequences in the BLAST GenBank database, and data obtained from the sequencing of these virulence genes were submitted to GenBank under different accession numbers. A phylogenetic analysis of the 16S rRNA gene sequence found a high similarity between local sequences and the closely related sequences of genes in GenBank. The presence of the viaB, staA, cdtB, and orfL virulence genes in nearly all of the isolates under examination suggests that they play an important role in the pathogenicity of local isolates.

Lippia origanoides and Thymus vulgaris Essential Oils Synergize with Ampicillin against Extended-Spectrum Beta-Lactamase-Producing Escherichia coli.

(1) Background: Could compounds such as monoterpenes and sesquiterpenes present in essential plant oils inhibit bacterial growth as an alternative to help mitigate bacterial resistance? The purpose of this study is evaluating the in vitro antibacterial effect of Lippia organoides EO (LEO) and Thymus vulgaris EO (TEO), individually and in combination with ampicillin, against extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli strains; (2) Methods: Experimental in vitro design with post-test. The EOs were obtained by hydrodistillation and were analyzed by GC. ESBL-producing E. coli strains used were selected from urine cultures and the blaCTX-M and blaTEM resistance genes were identified by end point PCR. The disk diffusion method was used for the susceptibility tests. The MICs and MBCs were determined by microdilution test. Finally, the interaction effect was observed by checkerboard assay; (3) Results: A 39.9% decrease in the growth of the strain thymol in TEO and 70.4% in carvacrol in LEO was shown, observing inhibition halos of 32 mm for both EOs. MICs of 632 and 892 μg/mL for LEO and 738 and 940 μg/mL for TEO were determined. Finally, it was observed that, at low doses, there is a synergistic effect between TEO + LEO and EOs + ampicillin; (4) Conclusions: The findings demonstrate that TEO and LEO have an inhibitory effect on ESBL-producing E. coli, suggesting that they are candidates for further studies in the formulation of antibiotics to reduce bacterial resistance to traditional antibiotics.

Identification of novel drug targets to counteract efflux pump mediated multidrug resistance in Acinetobacter baumannii

The emergence of multidrug-resistant (MDR) Acinetobacter baumannii poses an escalating threat to the healthcare system worldwide. A significant factor contributing to increasing resistance is the overexpression of chromosomally encoded efflux pumps, which expel antibiotics from bacterial cells, thereby rendering treatments less effective. The efflux pumps not only mediate resistance to antibiotics through drug efflux but also work synergistically with other resistance mechanisms, thereby doubling the resistance. Despite their crucial role in antibiotic resistance, understanding of the structure, function, mechanisms of action, and regulation of efflux pumps remains limited, which is necessary for devising effective strategies to restore drug susceptibility and to combat MDR isolates. In this context, the present study evaluated the prevalence of efflux pump overexpression in clinical A. baumannii isolates using phenotypic and genotypic methods and identified potential therapeutic targets employing a network-based approach. A total of 172 A. baumannii isolates were collected and subjected to antibiotic susceptibility tests using the Kirby-Bauer disk diffusion method. All the isolates were found to be MDR, with 94.76 % showing resistance to carbapenems. Efflux pump overexpression was detected in 54.65 % of isolates using the Ethidium-Bromide Agar Cartwheel method, and efflux pump inhibitory activity was observed in 68.71 % of isolates using cyanide m-chlorophenylhydrazone (CCCP). A total of thirteen efflux pump genes were detected in the tested isolates using diagnostic PCR, which were considered for interaction network analysis using STRING. Clustering analysis of the merged network identified two highly interconnected clusters, each comprising functional partners crucial for efflux pump function and regulation. Key hub genes, including AdeB, AdeJ, AdeK, AdeC, macB, tolC, AIL80285.1, AdeR, and AdeS, were identified as primary targets due to their significant influence on the network. Additionally, 24 clustered genes were pinpointed as potential drug targets for developing novel therapeutics to combat the formidable challenge of efflux pump-mediated MDR in A. baumannii.

Phenotypic characterization and antibiotic resistance of enterobacteria strains isolated from samples of patients in the towns of Moundou and Sarh in Chad

Today, enterobacteria constitute one of the most predominant causes of nosocomial and acquired infections in our communities. The bactericidal action of antibiotics on bacteria is used therapeutically, unfortunately the latter have started to develop resistances. Antibiotic resistance remains a major global public health issue, a serious problem in some of the world's poorest countries such as Chad. The objective of this study is to identify the strains of enterobacteria coming from samples of patients admitted to the Moundou and Sarh health centers, and to report their resistance profiles. A total of 278 samples consisting of urine (133) and stools (145) were collected in the laboratories of the two provincial hospitals of Sarh and Moundou between September and December 2021. The samples were processed and analyzed according to standard microbiology methods. The study of the sensitivity of different strains of enterobacteria with 14 antibiotic disks was evaluated by the disk diffusion method in agar medium. A total of 278 samples (urine, stool) including 111 strains of Enterobacteria, including 55 strains of E. coli, Enterobacter spp (n=17), klebsiella (n=11), Salmonella (n=9), Serratia ( n=7), Citrobacter (n=6) and Shigella (n=2) were isolated in the laboratory in the towns of Moundou and Sarh in Chad. The antibiogram carried out on all isolated strains of enterobacteria expressed a resistance ranging between 33.3% and 83.3% to 3rd generation cephalosporins, 30.3% and 50.0% to aminoglycosides. On the other hand, a strain of Salmonella is resistant to imipenem in Sarh. This study shows a high level of resistance acquired to different families of antibiotics by our bacterial strains studied. This resistance highlights the need to adapt therapeutic regimens to local epidemiology. Keywords : Characterization, Phenotype, Antibiotic resistance, Enterobacteria, Cities, Chad

Identification of vancomycin resistance in enterococcus & determination of minimal inhibitory concentration of vancomycin by E-test

Infections due to Enterococcal species is 2 prevalent cause of Nosocomial Infections in health care settings. They are crucial because to their inherent resistance to penicillins, cephalosporins, and low level aminoglycosides & their tendency to develop higher level of aminoglycoside and vancomycin resistance, which leaves few therapeutic alternatives for therapy. Isolation and identification of Enterococci with their Antibiogram & determination of Minimal Inhibitory Concentration (MIC) of Vancomycin by E-test. The antibiogram generated by Kirby Baur disc diffusion method and standard microbiological procedures were used to identify enterococcal isolates from distinct clinical samples. MIC level for Vancomycin was tested for all the isolates using E-test from BIOMERIEUX. Total of 108 isolates (62 E.faecalis and 46 E. faecium) were tested by E-test for MIC of Vancomycin, of which 40 (37.03%) (22 E.faecalis & 18 E. faecium) were Vancomycin Resistant (VRE) strains, having MIC level >32 μg/ml. Nine strains out of 40 (45%) were found to have MIC >256 μg/ml. The enterococcal isolates were observed to be sensitive to Linezolid (80%), Ofloxacin (74%), Amoxyclav (74%) and Cefaperazone (70%). For the Indian medical community, the rise of antibiotic resistance among Enterococcal species has been a significant concern. So this is need of present era that our laboratories must be well-equipped to report the resistance patterns displayed by enterococci in order to practise evidence-based medicine and reduce hospital acquired infections.

Antibacterial and antibiofilm effect of Zinc Oxide nanoparticles on P. aeruginosa variants isolated from young patients with cystic fibrosis

BackgroundP. aeruginosa, a biofilm-forming bacteria, is the main cause of pulmonary infection in CF patients. We applied ZnO-np as a therapeutic agent for eradicating multi-drug resistance and biofilm-forming P. aeruginosa isolated from young CF patients. MethodsA total of 73 throat and sputum samples taken from young CF patients were inquired. ZnO-np was synthesized and characterized in terms of size, shape, and structure for anti-bacterial activity. The antibiotic susceptibility of isolates before and after the addition of 16 μg/ml of ZnO was evaluated using disc diffusion and microtiter methods, respectively. The gene expression level of QS genes was assessed after treatment with 16 μg/ml ZnO-np. ResultsThe optimum concentration of ZnO-np with a higher inhibitory zone was 16 μg/ml (MIC) and 32 μg/ml (MBC). All isolates were resistant to applied antibiotics, and about 45 % of isolates were strong biofilm-forming bacteria. After treatment with 16 μg/ml ZnO-np, all strains became susceptible to the applied antibiotic except for amikacin, which confers an intermediate pattern. About 63 % and 20 % of isolates were, respectively, non-biofilm and weak biofilm-forming bacteria following the addition of ZnO-np. Relative gene expression of gacA, lasR, and rhlR genes were downregulated significantly (P < 0.001). Although the retS did not have a significant reduction (P = 0.2) ConclusionZnO-np at a concentration of 16 μg/ml could significantly reduce the P. aeruginosa infection by altering the antibiotic susceptibility pattern and inhibiting biofilm formation. Due to their photocatalytic properties and their ability to penetrate the extracellular polysaccharide layer, ZnO nanoparticles can produce ROS, which increases their susceptibility to antibiotics. Nasal delivery of ZnO-np in the form of aerosol can be considered a potential strategy to decrease the mortality rate in CF patients at an early age.

SHEDDING LIGHT ON GENETIC RELATIONSHIPS, PLASMID PROFILES AND ANTIBIOTIC RESISTANCE PATTERNS OF CLINICAL ESCHERICHIA COLI STRAINS: PULSED-FIELD GEL ELECTROPHORESIS PERSPECTIVE

In the present work, 47 Escherichia coli isolates collected from various clinical samples were elucidated with regard to genetic relationship, antibiotic resistance and plasmid profile. The genetic diversity of the isolates was defined by the pulsed field gel electrophoresis (PFGE) method. With a degree of similarity of 80%, the results from PFGE separated the E. coli strains into 39 different groups representing four subtypes. Antibiotic resistance patterns and extended spectrum of beta lactamase (ESBL) producing properties of the strains were determined by using a disk diffusion and double disc synergy method, respectively. According to the susceptibility test results, 36 distinct resistance profiles (resisto type) were observed among clinical strains. The strains were mostly resistant to ampicillin (100%) and this has been followed by cephalothin and ticarcillin/clavulanic acid with the ratio of 89.36%, cefuroxime with the ratio of 87.24%, tetracycline and cefotaxime with the ratio of 80.85%. It was observed that 24 of the strains (51.06%) were defined as ESBL positive. When E. coli strains were evaluated according to plasmid size, it was determined that 27 of 47 strains (57.44%) carried plasmids and the sizes of the determined plasmids were ranging between 77.1 kb and 1.6 kb. It was concluded that plasmids of E. coli strains are randomly distributed and no significant correlation was found between antibiotic resistance patterns and plasmids.

Occurrence and Antibiotic Resistance Profiles of Metallo Beta Lactamase Producing Pseudomonas aeruginosa among Clinical Isolates in Enugu Metropolis, Nigeria

Introduction: Antibiotic resistance is rising worldwide, posing a challenge for contemporary medicine. Metallo-beta-lactamases (MBLs) confer resistance to beta-lactam antibiotics other than monbactams. It threatens public health because of its vast scope of action and quick spread. The study was undertaken to assess the occurrence of MBL in clinical isolates of Pseudomonas aeruginosa in the Enugu metropolis and to determine their resistance profile. Materials and Methods: The work was conducted from October 2020 to July 2021 in the microbiology laboratory of the University of Nigeria Teaching Hospital, Ituku-Ozalla. A total of 127 non-duplicate bacterial isolates recovered from clinical samples including wounds, urine, sputum, ear discharge, and catheter tip processed in the microbiology laboratory of four referral hospitals within the Enugu metropolis was used for the study. Isolates were identified and characterized using standard microbiology protocols. Antimicrobial susceptibility was done using the Kirby-Bauer disc diffusion method. Phenotypic detection of Metallo-beta-lactamase production was done using the Combined Disk diffusion Test (CDDT). Results: Of the 127 isolates, 68 (53.5%) were resistant to imipenem. Among these, 35 strains were positive for MBL production while 33 isolates were non-MBL producers. The highest percentage occurrence of MBL producers was recorded from catheter tips 33% followed by urine 30.6%. Both MBL producers and non-MBL producers displayed high resistance to most of the antibiotics used except Aztreonam. Conclusion: The overall occurrence of MBL among Pseudomonas aeruginosa in our study was found to be 27.6%. MBL-producing strains showed higher resistance than the non-MBL-producing strains. Aztreonam was the most potent antibiotic. The most effective approaches to combating this organism include early detection, stringent antibiotic regimens, and adherence to infection control measures.

Extended spectrum and metalo beta lactamase producing gram negative bacterial pathogens from cockroaches collected at hospital, Southern Ethiopia

BackgroundCockroaches can pose a significant health risk in hospital environments because they may serve as reservoirs and vectors for nosocomial pathogens. Cockroaches harbor epidemiologically significant extended spectrum and metalo beta lactamase producing Gram negative bacterial pathogens, which complicate nosocomial infections.ObjectivesThe main aim of this study is to determine aetiology and phenotypic extended spectrum and metalo beta lactamase producing Gram negative bacteria pathogens from cockroaches collected in hospitals.MethodsA cross-sectional study was employed from February to May 2022 to determine the antibiotic resistance producing bacterial isolates from cockroaches by giving special emphasis to metalo beta lactamase and extended spectrum beta lactamase production from different wards of WSUCSH. Cockroaches were collected with hands wearing sterile gloves. External homogenate was prepared and incubated microbiologically by using different culture media and differentiated biochemically. Antimicrobial susceptibility testing was performed by disk diffusion method. ESBL production was conducted using double disc synergy method and double disk method was used to detect MBL enzyme detection. Descriptive statistics was used to determine prevalence and percentage.ResultOut of 245 cockroaches, 108 Gram negative bacteria were isolated. K. pneumoniae 29(26.9%) was the most predominant bacteria and Enetrobacter spp. 8(7.4%), was the least. All, K. pneumoniae, P. mirabilis, and Enterobacter isolates were pan-resistant to Ampicillin. P.aeruginosa and P.mirabilis antibiotics showed ≥ 80% resistant for amoxicillin/clavulanic acid antibiotics. Cefotaxime, ceftazidime, ceftriaxone and imipenem showed relative efficacy compared with other antibiotics. Out of 78 amoxicillin-clavulanic acid resistant isolates, 42(34.7%) were ESBL producers. ESBL production is more depicted by P. aeruginosa, A. baumannii, K. pneumoniae and E. coli. The overall prevalence of MBL production is 29(23.1%). K. pneumoniae P. aeruginosa, E.coli, A. baumannii, Enterobacter spp and K.oxytoca revealed MBL production.ConclusionThe overall prevalence of ESBL and MBL producing nosocomial agents from hospital cockroaches was 34.7% and 23.1% respectively. P.aeruginosa, A.baumannii, K.pneumoniae and E.coli showed pronounced ESBL production. All bacterial isolates except P. mirabilis and C. freundii showed MBL production. The needed to evaluate our antibiotic stewardship program and antibiotic resistance detection for treatment is mandatory. The impact of cockroach as a source of AMR should be sought.

Bacterial pathogens and antimicrobial susceptibility in ocular infections: A study at Boru-Meda General Hospital, Dessie, Ethiopia

IntroductionThe eye consists of both internal and external compartments. Several variables, including microbes, dust, and high temperatures can cause eye illnesses that can result in blindness. Bacterial eye infections continue to be a major cause of ocular morbidity and blindness, and their prevalence is periodically rising. The objective of the study was to detect bacterial pathogens and assess their susceptibility profiles to antibiotics in the ophthalmology unit of Boru-meda Hospital in Dessie, Ethiopia.MethodsA hospital-based cross-sectional study was conducted from February 1 to April 30, 2021, among 319 study participants with symptomatic ocular or peri-ocular infections who were enrolled using a consecutive sampling technique. After proper specimen collection, the specimen was immediately inoculated with chocolate, blood, and MacConkey agar. After pure colonies were obtained, they were identified using standard microbiological methods. The Kirby Bauer disk diffusion method was used to test antimicrobial susceptibility patterns, based on the guidelines of the Clinical and Laboratory Standards Institute.ResultsThe majority of participants developed conjunctivitis 126 (39.5%), followed by blepharitis 47 (14.73%), and dacryocystitis 45 (14.1%). Overall, 164 (51.4%) participants were culture positive, six (1.9%) participants had mixed bacterial isolates, giving a total of 170 bacterial isolates with an isolation rate of 53.3%. The predominant species was CoNS 47 (27.6%), followed by S. aureus 38 (22.4%) and Moraxella species 32 (18.8%). The overall Multi-Drug Resistance (MDR) rate was 62.9%, with 33 (44.6%) being gram-negative and 74 (77.1%) being gram-positive isolates.ConclusionConjunctivitis was the dominant clinical case and CoNS, was the predominant isolate. A higher rate of MDR isolates, particularly gram-positive ones, was observed. Efficient peri-ocular or ocular bacterial infection surveillance, including microbiological laboratory data, is necessary for monitoring disease trends.

FORMULATION OF PROPOLIS-BASED RECURRENT APHTHOUS STOMATITIS (RAS) PROTECTIVE PATCH WITH COMBINATION OF PVP AND CELLULOSE MATERIALS

Objective: The objective of this study was to obtain a mucoadhesive patch for recurrent aphthous stomatitis (RAS) with propolis, proven propolis’ antibacterial ability against bacteria in the oral cavity, and to obtain the physical characteristics of the produced patch. Methods: The patch was produced using a solvent-casting method. The antibacterial properties were determined by the disc diffusion method against S. mutans, S. oralis, S. sanguinis, and S. gingivalis. The physical characteristics of the patch was determined by examining weight and thickness dimension, swelling, surface pH, and structure observation. Results: The patch was made from 8 formulations with different propolis concentrations, Polyvinylpyrrolidone (PVP), and the use of cellulose materials (Hydroxypropyl methylcellulose and Carboxymethylcellulose). The concentrations of propolis used were 3%, 5%, 7%, and 10%. While the ratio of PVP and cellulose material in the formulation is 2:1. Results showed that propolis had a zone of inhibition greater than 2 mm against S. oralis, S. sanguinis, S. mutans, and P. gingivalis bacteria. Patches produced were clear to brown-colored films with high swelling percentage due to hydrophilic polymers used. The patch thickness that is closest to the requirements of the buccal patch was F8 with 0.36+0.04 mm. The mean values of the patches have matched normal salivary pH of 5.5–7. Physically, PVP/CMC formulations were more sticky, and the PVP/HPMC patches were more solid and stronger. Conclusion: A mucoadhesive patch was obtained with a combination of PVP/CMC and PVP/HPMC, tween 80 as a surfactant, glycerin as a plasticizer, peppermint oil as a flavor enhancer and preservative, with the active ingredient propolis.

Investigation of Cytotoxic Effects and Antimicrobial Activities of Light-cured and Self-cured Universal Adhesive Systems

Objective: This study aimed to compare the cytotoxicity and antimicrobial activity of a light-cured adhesive system and a self-cured adhesive system from the same company. Materials and Methods: A Tokuyama BOND force II (Light-cured) adhesive system (TF2B) and a Tokuyama Universal Bond (Self-cured) adhesive system (TUB) were selected for the study. The cytotoxicity evaluation of these two systems on cell cultures was performed using MTT assay and Agar Diffusion assay in L929 fibroblast cells. Disk diffusion method and liquid microdilution (MIC) method were used to evaluate their antimicrobial activity. The experiments were performed on 6 pathogenic bacteria and 1 yeast fungus. Results: According to MTT test results, both adhesive systems have no significant toxic effect on healthy cells (L929). However, when TUB and TF2B were compared with each other, it was found that TF2B had almost no toxic effect. In the agar diffusion test, when the two bonds were compared with each other, a weak color lightening was observed only around the first concentration of TUB. No visible melting was detected in other concentrations of TUB and TF2B. Both adhesive systems failed to reach MIC values effectively on the test microorganisms. Since the results were far above the MIC values of the reference antibiotics, it was determined that they did not have antimicrobial effects. Disk diffusion results similarly showed that both bonds did not form an inhibition zone on the test microorganisms. Conclusions: In dentistry, cytotoxic effects of universal adhesive systems on living cells can be observed. Self-cured and Light-cured adhesive systems did not show toxic effects on L929 cells. In addition, antimicrobial effects on test microorganisms were not detected. The cytotoxicity of the materials can be tested on different cells.

Changing Face of Antimicrobial Resistance: A Cross-Sectional Study

Introduction Infections of sterile body fluids are significant contributors to mortality and morbidity. Accurate species-level identification and understanding of the antimicrobial resistance profiles are crucial for selecting appropriate antimicrobials for empirical and targeted therapy. This study aims to examine the distribution of various bacterial species and their evolved antimicrobial resistance profiles isolated from different body fluids. Methods This retrospective study evaluated 301 body fluid samples collected at a tertiary hospital between January 2023 and December 2023. Samples were gram-stained and cultured on an appropriate media. Bacterial identification and susceptibility testing were performed using the BD Phoenix™ system, with disk diffusion method used for antibiotics not available in the system. Results Microbial growth was detected in 151 cases (50.2%), with a comparable prevalence among males and females (53.0% vs. 46.7%). The mean age was 49.81± 24.1 years. Growth rates were slightly higher in hospital-acquired infections (55.7%) than in community-acquired infections (49.2%). Cerebrospinal fluid showed the highest growth rate at 34.3%. Among the isolates, Streptococcus species were the most common (14.6%), while Escherichia coli was the predominant Gram-negative bacterium (13.2%). Sensitivity was highest with tigecycline (100%) and meropenem (92%), whereas resistance was most notable against ampicillin-sulbactam (100%) and azithromycin (95.2%). Multidrug resistance was identified in 106 isolates (70.2%). Conclusion High antibiotic resistance and multidrug-resistant strains underscore the need for rigorous antibiotic stewardship and improved infection control to address untreatable infections.

Antibacterial Effects of Basil (Ocimum sanctum) Leaf Extract in Combination with Meropenem against Extended Spectrum Beta-Lactamase (ESBL) Producing Klebsiella pneumoniae

Highlights: O. sanctum leaf extract does not significantly increase its antibacterial effects when combined with meropenem against ESBL-producing K. pneumonia. O. sanctum leaf extract has different antibacterial effects depending on geological and environmental factors. Abstract Introduction: Antibiotic usage for bacterial infections causes antibiotic resistance in bacteria. One is extended-spectrum beta-lactamase (ESBL), which produces Klebsiella pneumoniae, a pathogen responsible for increased antibiotic resistance. Basil (Ocimum sanctum) is a candidate for combination therapy. It has been proven to have antibacterial effects. However, its combination with antibiotics is rarely researched. This study evaluated the antibacterial effects of O. sanctum leaf extract and meropenem combination against ESBL-producing K. pneumoniae. Methods: This study used the disk diffusion method. The extract was tested for each experiment at 6%, 4%, 2%, 1%, and 0.5% concentration. The research was divided into two experiments to evaluate the antibacterial effects of O. sanctum leaf extract (n = 18) and its combination with meropenem against ESBL-producing K. pneumoniae (n = 18). The data was analyzed using the International Business Machines Corporation (IBM) Statistical Package for the Social Sciences (SPSS) version 26.0 for Windows. A probability (p) value of &lt; 0.050 was considered significant. Results: The first experiment showed that the extract had the largest antibacterial effect at 0.5% concentration (n = 18, p = 0.007). Meanwhile, the second experiment showed that the combination of the extract and meropenem did not have significant antibacterial effects (n = 18, p = 0.597). Conclusion: O. sanctum leaf extract has viable antibacterial effects, but its combination with meropenem does not significantly improve its antibacterial effects against ESBL-producing K. pneumonia.

Quality Test of Drinks from Carica Papaya Tip with Addition of Artocarpus Heterophyllus L.

Drinks from papaya seeds and jackfruit have the potential to become functional drinks with health benefits. This study aims to test the quality of drinks from papaya seeds with the addition of jackfruit in various comparisons. The research method used was pre-test and post-test experimental design by analyzing data descriptively using table results. The quality parameters tested include antimicrobial tests on Escherchia colli bacteria, Staphyllococcus aureus bacteria, Candida albicans fungus using the disc diffusion method (well diffusion), vitamin C content test using the volumetric method, color, aroma, taste, and consumer liking with organoleptic testing. The results showed that the addition of jackfruit significantly had antibacterial effectiveness, and had vitamin C levels in composition 1 (5 gr papaya seeds) with a result of 0.2804%, and in composition 2 (4 gr papaya seeds: 1 gr jackfruit) with a result of 0.1400%. The color of the drink becomes brighter with the addition of jackfruit. The aroma and taste of the drink also became better with the addition of jackfruit. Based on the results of the consumer favorability test, drinks with a ratio of papaya seeds and jackfruit in composition 2 are most favored by panelists. Drinks from papaya seeds with the addition of jackfruit have good quality and are favored by consumers. This drink has the potential to become a functional drink with health benefits.

Molecular and phenotypic characterization of biofilm formation and antimicrobial resistance patterns of uropathogenic staphylococcus haemolyticus isolates in Casablanca, Morocco

This study aimed to establish the correlation between antibiotic resistance and biofilm formation by Staphylococcus haemolyticus and to examine the impact of sub-inhibitory concentrations of antibiotics (sub-MICs) on biofilm formation.Antibiotic susceptibility testing was conducted using the disk diffusion method, and biofilm formation was determined using Congo red agar and microtiter plate methods. Antibiotic resistance and biofilm-associated genes were detected using polymerase chain reaction.The majority of the twenty-one S. haemolyticus isolates were multidrug-resistant, methicillin-resistant (MRSH) and biofilm producers, including 43 % of moderate biofilm producers. A significant correlation was observed between MRSH and MSSH isolates in terms of biofilm production. Vancomycin, gentamicin, and ciprofloxacin at their sub-MICs tended to promote biofilm formation. The eno gene was present in 76.2 % of strains, followed by aap, and atlE.This study revealed a strong correlation between the biofilm-forming ability and antibiotic resistance in S. haemolyticus, which underlines a crucial public health issue.

Antibacterial Resistance and Extended-Spectrum Beta-Lactamase (ESBL) Phenotypes in Enterobacteriaceae Isolated from Fecal Samples of Humans and Animals in Selected Local Government Areas of Nasarawa State, Nigeria

It is quite alarming the increasing rate of antibacterial resistance all over the world considering the public health threat and the re-emergence of multi-drug resistant Enterobacteriaceae. The aim of this study is Antibacterial resistance and phenotypic detection of Extended Spectrum Beta-Lactamase (ESBL) producing Enterobacteriaceae isolated from human and animal fecal samples in selected local government areas of Nasarawa state, Nigeria was carried out in the study. Hundred (100) samples comprising human and animal (goats, cattle, and chicken) were collected and 55 samples were multidrug resistant. A commercial biochemical kit (Eneterosystem 18R) was used for the isolation and identification of Enterobacteriaceae. Kirby Bauer Disk Diffusion Method was used for antibacterial susceptibility testing of Enterobacteriaceae isolates. The Double Disc Synergy Test (DDST) method was also used for the phenotypic confirmation test of Extended Spectrum Beta Lactamase (ESBL). The occurrence of multidrug-resistant isolates shows that Escherichia coli (100.00%) which is the highest, Proteus mirabilis (14.54%), Klebsiella pneumoniae, and Salmonella enterica (10.90%), while the occurrence of Shigella flexneri (9.09%) was the lowest. The Enterobacteriaceae isolates were more resistant to Cefuroxime, Cefexime, Amoxicillin Clavulanate, and Imipenem/Cilastatin with percentage resistance ranges from 66.6% - 100%. The occurrence of ESBL producers shows that Escherichia coli (60.00%) and Proteus mirabilis (62.5%) were high while Shigella flexneri (20.0%) had a low occurrence of ESBL. The sale and in-discriminate use of antibiotics without a prescription is an important regulatory issue in the abuse of antibiotics for both humans and animals. The Beta-Lactam and gentamycin antibiotics were not effective against the Multi-Drug Resistant (MDR) isolates and most of the isolates were ESBL producers.

Extended-spectrum beta-lactamase (ESBL) production and virulence genes profile of avian pathogenic Escherichia coli (APEC) isolated from broiler chickens in eastern Thailand

Avian pathogenic Escherichia coli (APEC) causes colibacillosis, resulting in extensive economic losses for the broiler industry. To date, there is little information in Thailand about virulence-associated genes and antibiotic resistance of APEC strains. Here, this study aimed to investigate the virulence genes and extended-spectrum beta-lactamase (ESBL) characteristics of APEC isolated from broilers. This study used multiplex polymerase chain reaction (PCR) to determine the presence of virulence genes and resistance genes in APEC. Furthermore, the disc diffusion method examined ESBL phenotypes of APEC and antibiotic resistance profiles against 17 antimicrobials. In this study, E. coli was isolated 11 (6.32%) of 174 broiler visceral organs. All E. coli isolates were tested for five APEC-virulence-associated genes (iroN, ompT, hlyF, iutA, and iss). Eight E. coli isolates from broilers with colibacillosis-associated lesions carried two (iroN and ompT) of the APEC virulence genes. One APEC virulence gene (hlyF) was found in E. coli isolates from broilers without lesions. Possibly no individual virulence gene was specific to the APEC strain. Interestingly, the papC, previously detected in humans with uropathogenic E. coli, was found in an APEC isolate. All APEC isolates were ESBL-producing E. coli, and then they were tested for four beta-lactamase-encoding genes (blaTEM, blaCTX-M, blaOXA, and blaSHV). The blaTEM and blaCTX-M were identified in 81.81% (9/11) of the isolates, whereas blaOXA or blaSHV were not detected in any isolate. All APEC showed multi-drug resistance (MDR) phenotypes, especially chloramphenicol, erythromycin, and sulfamethoxazole-trimethoprim. Although antibiotics were not recently used, MDR might be encouraged by horizontally transferring antibiotic-resistance genes. In addition, fluoroquinolone resistances were found in APEC isolates which could transfer resistance genes to humans via the food chain. This study indicates that APEC isolates contain several virulence and bla genes and should be surveillance to prevent the transmission of those genes to humans.