Mueller-Hinton Research Articles

Uji Resistensi Campylobacter sp. Yang Diisolasi Dari Rusa Timor (Rusa Timorensis) Terhadap Antibiotik

Timor deer (Rusa timorensis) is a protected animal and is categorized as vulnerable in the International Union for Conservation of Nature of Threatened Species Red List (IUCN Red List). Efforts to save and prevent timor deer from extinction are through conservation in captivity. Captive-bred timor deer can be infected with Campylobacter sp. which is one of the causes of diarrhea in humans. Antibiotic resistance to Campylobacter sp. has been widely reported in various parts of the world. Timor deer are not directly exposed to antibiotics but can experience antibiotic resistance due to interactions with humans. The purpose of this study was to determine resistance and determine the level of resistance of Campylobacter sp. isolated from timor deer to antibiotics. This research was conducted using Campylobacter sp. isolates on modified charcoal-cefoperazone-deoxycholate agar (mCCDA) media. Kirby-Bauer method resistance test with Mueller-Hinton agar media using test antibiotics: ampicillin, ciprofloxacin, erythromycin, chloramphenicol, and tetracycline. Data were analyzed by looking at the inhibition zone formed and compared with Clinical and Laboratory Standards Institute (CLSI) standards. The results showed that Campylobacter sp. from timor deer had developed resistance to ampicillin, erythromycin, and tetracycline antibiotics. The inhibition zones formed from the five types of test antibiotics were ampicillin (7.58 mm), ciprofloxacin (26.76 mm), erythromycin (11.65 mm), chloramphenicol (24.40 mm), and tetracycline (9.05 mm).

Investigating lactic acid bacteria genus Lactococcus lactis properties: Antioxidant activity, antibiotic resistance, and antibacterial activity against multidrug-resistant bacteria Staphylococcus aureus

BackgroundLactic acid bacteria (LAB) are utilized as a starter culture in the manufacturing of fermented dairy items, as a preservative for various food products, and as a probiotic. In our country, some research has been carried out, even if LAB plays a principal role in food preservation and improves the texture and taste of fermented foods, that is why we tried to evaluate their probiotic effect. The objective of this research was to determine the antibacterial activity of Lactococcus lactis (L. lactis) against Staphylococcus aureus (S. aureus) ATCC 29213, investigate their antioxidant activity, and characterize their sensitivity against 18 antibiotics. MethodsA total of 23 LAB (L. lactis subsp. cremoris, L. lactis subsp. Lactis diacetylactis, L. lactis subsp. lactis) were isolated from cow's raw milk. The antibacterial activity was performed using two techniques, competition for nutrients and a technique utilizing components nature, using the disk diffusion method. The sensitivity of the studied LAB to different antibiotics was tested on Man rogosa sharp (MRS) agar using commercial antibiotic disks. All strains of LAB were examined for their antioxidant activity. The antioxidant activity of L. lactis was tested by 2,2-diphenyl-1 picrylhydrazyl (DPPH). ResultsThe results showed that the MRS medium was more adapted than Muller Hinton Agar (MHA) to investigate the antibacterial activity of L. lactis against S. aureus ATCC 29213. Also, L. lactis exhibited a notable degree of antibacterial activity against S. aureus ATCC 29213. L. Lactis subsp. Lactis displayed higher antibacterial activities, followed by L. lactis ssp. lactis biovar. diacetylactis, and lastly, L. lactis ssp. cremoris against S. aureus ATCC 29213. Lc 26 among all strains of L. lactis showed a high potential antibacterial activity reaching 40 ± 3 mm against S. aureus ATCC 29213. All strains of L. lactis showed a slightly moderate antioxidant activity (10.56 ± 1.28%-26.29 ± 0.05 %). The results of the antibiotic resistance test indicate that all strains of L. lactis were resistant to cefotaxime, sulfamethoxazole-trimethoprim, and streptomycin and were sensitive to Ampicillin, Amoxicillin, Penicillin G, Teicoplanin, Vancomycin, Gentamicin 500, Tetracycline, and Chloramphenicol. These test results indicate that this strain falls within the criteria of not posing any harmful effects on human health. The important antibacterial properties recorded for all L. Lactis strains were derived from the production of antibacterial active metabolites, such as protein, diacetyl, hydrogen peroxide, and lactic acid, together with the fight for nutrients. ConclusionThis study suggests that the strains of L. lactis could be added as an antibacterial agent against S. aureus ATCC 29213 and can provide an important nutritional property for their antioxidant potential.

Nasal carriage rate, associated factors, and antimicrobial susceptibility patterns of methicillin resistance Staphylococcus aureus among pre-clinical undergraduate students at the College of Health and Medical Sciences, Haramaya University, Ethiopia

BackgroundStaphylococcus aureus nasal carriage has been linked to higher rates of infection and morbidity. People with Methicillin-resistant Staphylococcus aureus can be a potential source of infection for others. University students living together in crowded conditions increase their risk of acquiring infections. The prevalence of S. aureus, particularly Methicillin-resistant Staphylococcus aureus nasal carriage, in Ethiopian university students is sparse.ObjectiveThis study aimed to determine the nasal carriage rate, associated factors, and antimicrobial susceptibility patterns of methicillin-resistant Staphylococcus aureus among pre-clinical students at the College of Health and Medical Sciences, Haramaya University, Ethiopia, from 1 July to 30 August 2022.MethodsAn institutional-based cross-sectional study was conducted among 270 randomly selected pre-clinical Health and Medical Sciences students. Data on associated factors were collected using pre-tested, structured questionnaires. A nasal swab was taken from each participant and sent to the microbiology laboratory via Amies transport media in a cold chain. There, it was cultivated using conventional techniques. The isolated colonies were found to be S. aureus, and its antimicrobial susceptibility was performed using the Kirby–Bauer disk diffusion method on Muller–Hinton agar. Methicillin-resistant Staphylococcus aureus expressing using cefoxitin based on CLSI breakpoint. Data were entered into Epi-Data version 4.4.2.1 and exported to the Statistical Package for Social Sciences (SPSS) software version 25 for analysis. Pearson’s chi-square test was performed to predict the associations between variables. A p-value less than 0.05 was regarded as statistically significant.ResultMethicillin-resistant Staphylococcus aureus nasal carriage was 5.9% (95% CI: 3.09–8.7) of cases of S. aureus nasal colonization, which was found to be 12.96% (95% CI: 8.85–16.96). Methicillin-resistant Staphylococcus aureus nasal colonization was significantly associated with the history of cigarette smoking (p = 0.000), intake of khat (p = 0.042), nose-picking habit (p = 0.003), history of sharing personal goods (p = 0.021), and history of hospitalizations (p = 0.00). All of the Methicillin-resistant Staphylococcus aureus isolates were resistant to ampicillin and cefoxitin.ConclusionBased on the findings, a considerable proportion of healthy students harbored Methicillin-resistant Staphylococcus aureus strains associated with behavioral factors. Furthermore, these isolates showed high resistance to cefoxitin and ampicillin. Hence, it is crucial to regularly test pre-clinical students to prevent endogenous infections and the spread of Methicillin-resistant Staphylococcus aureus.

Characterisation of a novel AmpC beta-lactamase, DHA-33, resistant to inhibition by cloxacillin

Plasmid-encoded DHA-type AmpCs have been extensively reported in Enterobacterales. The expression of the genes encoding these plasmid-mediated enzymes are inducible and these enzymes are capable of conferring resistance to a wide spectrum of beta-lactams including penicillins and broad-spectrum cephalosporins. The identification of infections caused by AmpC-producing bacteria is a necessity, both for infection control/epidemiology purposes and to inform treatment choices. A common testing method for AmpC production in the clinical laboratory setting is to supplement Mueller-Hinton agar plates used for antibiotic disk diffusion with cloxacillin, a potent inhibitor of AmpC enzymes. Here we describe a novel DHA variant, produced by a clinical Escherichia coli isolate, which is resistant to cloxacillin inhibition.

Assessment of Antimicrobial Efficacy of Triphala, Neem, and Chlorhexidine Root Canal Irrigants.

Complete eradication of microorganisms from the root canal and three-dimensional obturation of the canal space are necessary for a successful root canal therapy. In root canal failures, Enterococcus faecalis is the most often detected bacterium. Microorganisms can be eliminated with the aid of chemical irrigation. The current research was conducted to evaluate the antimicrobial effect of triphala, neem, and chlorhexidine root canal irrigants. Mueller-Hinton agar plates were inoculated with the E. faecalis (ATCC) bacterial culture after it had been cultured overnight in brain heart infusion (BHI) broth. Agar well diffusion was used to measure antibacterial inhibition. After being introduced to their appropriate wells in agar plates, the three research irrigants were incubated for 24 hours at 37°C. Every well's bacterial inhibition zone was noted. After tabulating the results, statistical analysis was done. When triphala and A. indica extract (neem) were added to chlorhexidine, the highest inhibitory zone against E. faecalis was observed. The herbal remedy triphala and the extract from A. indica exhibited an inhibitory zone when tested against E. faecalis. As a result, these irrigants might be utilized as a substitute for root canal irrigants.

Antimicrobial Resistance Profile of Foodborne Salmonella spp. and E. coli Isolates from Rodents and Shrews in Morogoro Municipality, Tanzania

Background: Antimicrobial resistance (AMR) is a pressing global public health issue that affects both human and animal health. Small mammals, such as rodents and shrews, represent a significant reservoir of zoonotic infections. However, there is limited documented research specifically addressing Escherichia coli and Salmonella spp. resistant strains from small mammals. Purpose: This study was conducted to examin the occurrence of AMR E. coli and Salmonella spp. and their associated resistance genes in rodents and shrews. Methods: A total of 148 fecal samples from rodents and shrews were examined for E. coli and Salmonella spp. using culture methods and biochemical tests. Fifty isolates were subjected to antibiotic susceptibility testing using the disk diffusion method on Muller-Hinton agar. Genotypic analysis by PCR was used to confirm the bacterial strains and their resistance pattern genes. Results: Two bacteria were confirmed in 57 (38.5%) of the fecal samples. Specifically, E. coli and Salmonella spp. were identified in 54 (36.5%) and 3 (2%) fecal samples, respectively. Antimicrobial susceptibility testing revealed significant resistance in Rattus rattus. Molecular analysis confirmed that Salmonella spp. carry a larger proportion of resistance genes than E. coli. Specific resistance genes, including Sul1 and Sul2, were identified, constituting 15.4% of the total resistance genes. The prevalence of β-lactamase genes was remarkable, with a higher occurrence in Salmonella spp. Conclusion: In terms of human health, the implications of rodents and shrews serving as carriers and transmitters of various pathogens were highlighted. Given the possibility of unexpected zoonoses arising from the bacteria found in this study, these findings contribute to the understanding AMR in the context of bacterial infections in animals and humans.

Multi-Omics of Campylobacter jejuni Growth in Chicken Exudate Reveals Molecular Remodelling Associated with Altered Virulence and Survival Phenotypes.

Campylobacter jejuni is the leading cause of foodborne human gastroenteritis in the developed world. Infections are largely acquired from poultry produced for human consumption and poor food handling is thus a major risk factor. Chicken exudate (CE) is a liquid produced from defrosted commercial chicken products that facilitates C. jejuni growth. We examined the response of C. jejuni to growth in CE using a multi-omics approach. Changes in the C. jejuni proteome were assessed by label-based liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). We quantified 1328 and 1304 proteins, respectively, in experiments comparing 5% CE in Mueller-Hinton (MH) medium and 100% CE with MH-only controls. These proteins represent 81.8% and 80.3% of the predicted C. jejuni NCTC11168 proteome. Growth in CE induced profound remodelling of the proteome. These changes were typically conserved between 5% and 100% CE, with a greater magnitude of change observed in 100% CE. We confirmed that CE induced C. jejuni biofilm formation, as well as increasing motility and resistance against oxidative stress, consistent with changes to proteins representing those functions. Assessment of the C. jejuni metabolome showed CE also led to increased intracellular abundances of serine, proline, and lactate that were correlated with the elevated abundances of their respective transporters. Analysis of carbon source uptake showed prolonged culture supernatant retention of proline and succinate in CE-supplemented medium. Metabolomics data provided preliminary evidence for the uptake of chicken-meat-associated dipeptides. C. jejuni exposed to CE showed increased resistance to several antibiotics, including polymyxin B, consistent with changes to tripartite efflux system proteins and those involved in the synthesis of lipid A. The C. jejuni CE proteome was also characterised by very large increases in proteins associated with iron acquisition, while a decrease in proteins containing iron-sulphur clusters was also observed. Our data suggest CE is both oxygen- and iron-limiting and provide evidence of factors required for phenotypic remodelling to enable C. jejuni survival on poultry products.

Short Communication: Investigation of mecA-positive and Methicillin-Resistant Staphylococcus aureus (MRSA) in dairy goat with subclinical mastitis from traditional farms in Banyuwangi, Indonesia

Abstract. Praja RN, Edila R, Yudhana A, Saputro AL, Hamonangan JM, Praja SS. 2024. Short Communication: Investigation of mecA-positive and Methicillin-Resistant Staphylococcus aureus (MRSA) in dairy goat with subclinical mastitis from traditional farms in Banyuwangi, Indonesia. Biodiversitas 25: 1638-1643. Raw milk has the potential to transmit bacteria resistant to antibiotics and serve as a medium for the development of food-borne illnesses. Staphylococcus aureus is a harmful bacterium that can infect host cells and carry antibiotic-resistant genes. This study aims to investigate the occurrence of Methicillin-Resistant Staphylococcus aureus (MRSA) which contains mecA coding gene from raw goat milk in Banyuwangi, East Java, Indonesia. 150 raw milk samples were collected from five goat farms in Banyuwangi, East Java, Indonesia. S. aureus was isolated using selective media, and antibiotic susceptibility testing was conducted using the Mueller-Hinton agar diffusion method. MRSA was confirmed using the oxacillin and cefotaxime resistance screen agar test, with the presence of mecA genes identified through polymerase chain reaction. The results show that the prevalence of S. aureus was 30.6%. Of the 46 S. aureus isolates, 28 (60.87%) were categorized as MRSA. The mecA gene was observed in 9 (32.14%) MRSA isolates. The presence of MRSA in raw goat milk poses a significant public health threat, as bacteria carrying the mecA gene for antimicrobial resistance can spread through animal products like raw milk. Enhanced hygiene and sanitation protocols in dairy goat farms are essential prevention measures that must be strictly implemented.

Prevalence and Antibiotic Susceptibility of Urinary Tract Infections in Diabetic and Non Diabetic Individuals: A Prospective Study

Background & Objectives: Diabetes mellitus is increasingly recognized as a major health concern worldwide, particularly in developing countries like India. Diabetic individuals are known to have a higher susceptibility to urinary tract infections (UTIs), compounded by the emergence of drug-resistant uropathogens. This study aims to determine the prevalence and etiology of UTIs in diabetic patients. Materials and Methods: A cross-sectional prospective study involving 220 individuals was conducted from March to April 2023 to assess the spectrum of pathogens causing UTIs and their antibiotic susceptibility. Primary cultures were performed on McConkey agar and sheep blood agar, followed by identification and antimicrobial susceptibility testing (AST) using the Vitek2 system and Kirby Bauer's disc diffusion method on Mueller-Hinton agar. Results: Of the 220 samples tested, 150 exhibited significant bacteriuria, with 36 (75%) of 48 diabetic individuals testing positive for UTIs. Gram-negative bacilli (GNB) accounted for 135 (61.4%) isolates, with Escherichia coli (E. coli) being the most prevalent pathogen (52.7%), followed by Klebsiella spp. (25.3%). Among gram-positive organisms, Enterococcus spp. (5.3%) were predominant, with Candida isolates detected in 3 cases (2%). Meropenem (87.6%) exhibited the highest susceptibility against GNB, followed by Netilmycin (87.6%) and Imipenem (82.5%). For gram-positive organisms, Imipenem and Nitrofurantoin demonstrated high susceptibility. Conclusion: E. coli emerged as the predominant pathogen in both diabetic and non-diabetic populations. High sensitivity to meropenem, imipenem, amikacin, and fosfomycin was observed in both groups, suggesting their potential for empirical treatment. Regular surveillance of drug resistance patterns is crucial for identifying evolving resistance trends and optimizing treatment strategies.

The microenvironment in antibiotic susceptibility testing.

Antibiotic susceptibility testing (AST) by agar diffusion has been repeatedly standardized and, in most cases, gives results which predict clinical success when antibiotic treatment is based on such results. The formation of the inhibition zone is due to a transition from planktonic to biofilm mode of growth. The kinetics of the interaction of antibiotics with bacteria is similar during AST by agar diffusion and during administration of antibiotics to the patients. However, the Mueller-Hinton agar (MHA) recommended for AST agar diffusion test is fundamentally different from the composition of the interstitial fluid in the human body where the infections take place and human cells do not thrive in MH media. Use of RPMI 1640 medium designed for growth of eucaryotic cells for AST of Pseudomonas aeruginosa against azithromycin results in lower minimal inhibitory concentration, compared to results obtained by MHA. The reason is that the RPMI 1640 medium increases uptake and reduces efflux of azithromycin compared to MHA. During treatment of cystic fibrosis patients with azithromycin, mutational resistance occur which is not detected by AST with MHA. Whether this is the case with other antibiotics and bacteria is not known but it is of clinical importance to be studied.

Preparation of Andrographis Paniculata and Rosa Formulation and its Antibacterial Activity Against Urinary Tract Infection Causing Pathogens

ABSTRACT Andrographis Paniculata also known as the “King of Bitters” is a herbal medicine of the Acanthaceae family which is native to India and Sri Lanka. Andrographis Paniculata is a very useful medicinal plant as it has antioxidant, antidiabetic, antipyretic, anticancer properties. The main antibacterial activity of Andrographis Paniculata is due to the presence of andrographolide and arabinogalactan proteins. The medicinal properties of rose are mostly due to their abundance in phenolic compounds. They have many pharmacological properties like antibacterial, antioxidant, thrombolytic, and anticancer properties. The hips of the rose plant have Vitamin C in a concentration that is three times more than a citrus fruit that can be used in the treatment of a flu or a cold. Mueller–Hinton agar was utilized for this activity to determine the zone of inhibition. The plant extracts with different concentrations were loaded, and the plates were incubated for 24 hours at 37°C. After the incubation time, the zone of inhibition was measured. The results of this study are significant because they demonstrate the antibacterial activity of Andrographis Paniculata and Rosa against three bacterial pathogens. This suggests that the formulation of Andrographis Paniculata and Rosa has potential as a natural antibacterial agent. Further studies are needed to explore the mechanism of action and potential applications of this formulation. In conclusion, the study shows that the formulation of Andrographis Paniculata and Rosa has significant antibacterial activity against Klebsiella, Escherichia Coli, and Enterococcus Faecalis. This suggests that the formulation of Andrographis Paniculata and Rosa has potential as a natural antibacterial agent that could be further explored for its potential use in the treatment of bacterial infections.

Antibacterial Activity of the Vancomycin and Cefotaxime-Incorporated Total Etch Adhesive System - An In Vitro Study.

Marginal failure at the resin dentin interface promotes biofilm formation, which further leads to secondary caries and hypersensitivity. This likelihood also increases if residual bacteria are present following cavity preparation. In order to achieve a proper biological seal without jeopardizing bonding, efforts were made to functionalize the adhesive system with antibacterial activity. Aim and objectives: To appraise the antibacterial activity of a total-etch adhesive system against S. mutans with and without incorporation of antibiotics Vancomycin and Cefotaxime. A commercially available 5th-generation total-etch bonding agent (Te-Econorm) was used. S. mutans broth had been standardized and streaked over Muller-Hinton agar culture medium and round wells about 6 mm in diameter were made in the centre of the agar plates. Each experimental group comprised 10 samples, which include: Group 1 - 30µg Cefotaxime, Group 2- 30µg Cefotaxime + Bonding agent, Group 3- 30µg Vancomycin, Group 4- 30µg Vancomycin + Bonding agent, Group 5- Bonding agent, and Group 6- No material. Inoculated culture plates were examined for the zone of inhibition after incubation at 37° C for 24 hours. There was a significant difference in the mean diameter of zone of inhibition (p=0.000), with the maximum exhibited by Group 4, followed by Group 3 and Group 2. The least zone of inhibition was exhibited by Groups 1 and 5. The negative control showed no zone of inhibition. The combination of Vancomycin and bonding agent had superior antibacterial activity against S. mutans in comparison to cefotaxime and bonding agent.

GRAM-NEGATIVE BACTERIA IN SOME CLINICAL SPECIMENS AND THEIR ANTIBIOTICS RESISTANCE PROFILES, SANA’A, YEMEN

Gram-negative bacteria (GNB) have emerged globally as significant public health problems owing to their high resistance to antibiotics, particularly in developing countries such as Yemen. Therefore, this study aimed to determine the antibiotic resistance profile of GNB isolated from clinical samples in Sana’a City, Yemen. A total of 420 clinical samples, including vaginal swabs, urine, and pus, were collected from patients who attended some hospitals in Sana’a City, Yemen, in 2018. The collected specimens were examined according to standard microbiological methods, and the isolated bacteria were tested against some antibacterial agents using the Kirby-Bauer disc diffusion method on Mueller-Hinton agar. Among 420 specimens, the prevalence of gram-negative bacteria infections was 49.76%. A high rate of GNB was reported among the age group of 41–50 years old (57.97%), female patients (52.19%), those who came from rural areas (60.0%), and those who were uneducated (86.56%). The vaginal specimens exhibited a higher prevalence of bacterial bacteria (60.42%), followed by urine (51.28%) and pus (35.0%). Escherichia coli accounted for the greatest proportion of bacteria recovered from the study's patients (36.62%), followed by Klebsiella pneumoniae (18.66%), Enterobacter sp. (12.32%), Acinetobacter sp. (10.92%), Pseudomonas aeruginosa (9.15%), Citrobacter sp. (6.34%), and Proteus mirabilis (5.99%). E. coli was highly resistant to imipenem and enrofloxacin. Similarly, K. pneumoniae and P. aeruginosa were highly resistant to imipenem and norfloxacin. About 62.86% of Enterobacter sp. isolates were resistant to imipenem. In addition, 83.33–78.97% of Acinetobacter sp. isolates were resistant to imipenem and meropenem. Citrobacter sp. had high resistance to norfloxacin. Additionally, over 50% of P. mirabilis isolates were resistant to ofloxacin, norfloxacin, cefuroxime, and ceftizoxime. The conclusion is that there exists a significant proportion of GNB prevalence and antibacterial resistance among the study subjects. Therefore, multisectoral approach is needed for implementing effective strategies to reduce the transmission of antibiotic-resistant bacteria among the community.

Antibacterial Activity of the Leaf Extract of Acalypha wilkesiana against some Human Bacterial Pathogens

Humanity has long been creating traditional treatments based on the knowledge of medicinal plants found worldwide. The medicinal potential of Acalypha wilkesiana in treating skin and gastrointestinal problems is highly appreciated. This study aimed to examine the Acalypha wilkesiana leaf extract's antibacterial effectiveness against a variety of human bacterial infections. Standard techniques were used to determine whether secondary metabolites were present in methanolic, ethanolic, and hot water extracts. The plant extracts were evaluated for their ability to inhibit the growth of bacteria obtained from Bells University of Technology, including Staphylococcus aureus, Staphylococcus saprophyticus, Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa. Agar diffusion was used for antibacterial activities, and Mueller Hinton Agar (MHA) minimum inhibitory concentration (MIC) was determined using the agar dilution method. According to the study's findings, the plant sample included flavonoids, tannin, alkaloids, and saponins. With a MIC of 2.5 mg/mL against Pseudomonas aeruginosa and Enterococcus faecalis and 5.0 mg/mL against Staphylococcus aureus, hot water extract exhibited the highest activity level against all tested isolates. As a result, Acalypha wilkesiana leaf extract exhibited broad-spectrum antibacterial activity.

Prevalence of Extensively and Pan-drug-resistant Acinetobacter spp. in Nosocomial Infections in Western Saudi Arabia

Multidrug resistance patterns of Acinetobacter spp. have led to their emergence as an important source of nosocomial infections. This study investigated the prevalence and clinical characteristics of Acinetobacter spp. in hospital-acquired wound and urinary tract infections. A total of 432 samples [wound swabs (210) and urine samples (222)] were analyzed for the presence of Acinetobacter spp. through selective culturing on MacConkey and Leeds Acinetobacter medium followed by identification with API 20E strips and Vitek 2 compact system. Antimicrobial susceptibility was assessed by adopting the disk diffusion method on Muller-Hinton agar, whereas the minimum inhibitory concentration procedure was carried out by using a ComASP™ Colistin test kit. Biofilm formation was examined using microtiter plates and following the crystal violet staining method. PCR was performed to amplify virulence (lasB, bap, and plcN) and antimicrobial resistance (blaOXA-51like) genes. The results revealed a low prevalence of Acinetobacter spp. (1.85 %) where Acinetobacter baumannii was the predominant species. Acinetobacter baumannii isolates harbored blaOXA-51-like gene to exert extensive or pan-drug resistance. Most Acinetobacter baumannii isolates demonstrated weaker to moderate biofilm-forming capabilities and carried the bap gene. Acinetobacter baumannii isolates lacked the combination of virulence factors encoding lasB and plcN genes. Acinetobacter baumannii infections are rising in Saudi Arabia. The results of this study highlight the epidemiology of virulent and antibiotic-resistant Acinetobacter spp., particularly A. baumannii, in Saudi Arabia. The detailed elaboration on the diversity, virulence, and antimicrobial susceptibility patterns of Acinetobacter spp. in Saudi Arabia requires further in-depth molecular investigations.

ANTIMICROBIAL POTENCY AND PHYTOCHEMICAL CONTENTS OF THREE COMMON NIGERIA MEDICINAL PLANTS’ LEAF EXTRACTS

Morinda lucida, Tithonia diversifolia and Carica papaya are three medicinal plants commonly used for curing several diseases in traditional medicine. However, comparative scientific information as regards their antibacterial, antifungal, and phytochemical properties remains limited. Fresh leaves of Morinda lucida, Tithonia diversifolia, and Carica papaya were harvested and extracted by soaking pulverized samples of the plants in 250 mL of water and ethanol. The phytochemical constituents were determined by subjecting the decoction to qualitative and quantitative tests using standard methods. The antimicrobial and antifungal activities were determined by solidified Mueller-Hinton agar plate and solidified Potato Dextrose agar plate respectively. Alkaloids, flavonoids, saponins, tannins, and terpenoids were shown to be the primary metabolites in the ethanolic extract of the three plant species. Cardiac glycosides are only present in T. diversifolia. Aqueous and ethanolic leaf extracts of the three species had significant, but varying antibacterial activity and no antifungal properties. Ethanolic extracts of Morinda lucida were the most active against Escherichia coli with a 30 mm zone of inhibition and very active against Klebsiella pneumonia and Enterobacter aerogenes with 28 mm and 24 mm zone of inhibition, respectively. The aqueous extracts of T. diversifolia were more active against Staphylococcus aureus, Serratia marscences, and Enterobacter aerogenes than ethanolic extract. The ethanolic decoction of C. papaya was active against Enterococci. This study showed that depending on the decoction solvent and the microbes under investigation, the leaf extracts of the three plant species have a tolerable but variable level of activity.

Study of disinfectant activity against bee pathogenic enterobacteria in vitro

Dysbiosis is a pathological condition caused by violating the normal coexistence of bacterial organisms in one or more body systems. This disease arises due to the action of many ethological factors, the mechanisms of which arise from each other. Klebsiellosis of bee colonies is a relatively new disease of Apis mellifera, caused by pathogenic enterobacteria, which leads to the mass death of bees with signs of acute dyspepsia, particularly in the spring and autumn periods. To prevent klebsiellosis in bees, it is necessary to carry out veterinary and sanitary measures in apiaries every year, including disinfection. Modern beekeeping encourages the search for new antibacterial drugs to ensure the production technology of safe and high-quality beekeeping products suitable for sale. Preliminary laboratory assessment (in vitro) of the effectiveness of disinfectants against specific pathogens of specific diseases of bees will ensure an increase in the effectiveness of such agents in apiaries, which is economically effective for practical beekeeping. The purpose of the research was to determine the activity of different concentrations of the disinfectant (0.25 %, 0.5 %, 1.25 %, 2.5 %) with an active substance of an organic nature with covalent weakly polar bonds against pure cultures of pathogenic enterobacteria of bees of the species Klebsiella pneumoniae and Klebsiella (Enterobacter) aerogenes in vitro. The modified Kirby-Baur method on Mueller-Hinton agar was used for research. A bactericidal effect against a pure culture of Klebsiella pneumoniae species was registered after 24 hours with lysis zone diameters at 8.6 ± 0.27 mm (0.25 % concentration) – 15.0 ± 0.35 mm (2.5 % concentration). On the 3rd day of research, a bacteriostatic effect was registered with the largest diameter of the zone of growth retardation (24.4 ± 0.27 mm) at 2.5 % disinfectant concentration. Bactericidal and bacteriostatic effects were recorded on the culture of enterobacteria of bees of the species Klebsiella (Enterobacter) aerogenes for 24 hours of cultivation with zones of lysis – 6.8 ± 0.42 mm (0.25 %) – 11.8 ± 0.22 mm (2.5 %) and inhibition of bacterial growth at the level of – 21.8 ± 0.42 mm (0.25 %) – 25.8 ± 0.42 mm (2.5 %). At the same time, there was no significant difference between the zones of Klebsiella (Enterobacter) aerogenes growth retardation in concentrations of 0.5 % – 2.5 % on the 3rd day of research. The studied disinfectant has bactericidal and bacteriostatic effects on pure cultures of bee enterobacteria of the species Klebsiella pneumoniae and Klebsiella (Enterobacter) aerogenes in laboratory conditions, which is promising for further study of the drug.

DETECTION OF METHICILLIN RESISTANCE IN CLINICAL ISOLATES OF STAPHYLOCOCCUS AUREUS IN TERTIARY CARE HOSPITAL, TIRUPATI

Objective: The study aimed to estimate the prevalence of methicillin resistance of Staphylococcus aureus in various clinical samples received at tertiary care hospital. Initially, the Staphylococcus aureus and its antibiotic susceptibility tests is performed in clinical samples which are submitted to the department of Microbiology. And Methicillin Resistance Staphylococcus Aureus (MRSA) is determined by using cefoxitin (30 μg) as per CLSI guidelines.
 Methods: The prospective study was conducted in department of Microbiology in a tertiary care hospital. All Staphylococcus aureus organisms isolated in clinical samples were included in the study and processed as per the standard operating procedure. Methicillin susceptibility was tested by using cefoxitin (30μg) disks on Muller-Hinton agar plates that were inoculated with a suspension (equal to 0.5 McFarland standards) of the s. aureus.
 Results: In our study, amongst hundred staphylococcus aureus isolates, sixty isolates were shown resistance to cefoxitin (30µg), which indicates that percentage of methicillin-resistant s. aureus in our study is 60. Majority of s. aureus were isolated from blood samples 44% (n= 44) followed by pus samples 32% (n=32). Linezolid resistance reported was 3%. All isolates were sensitive to vancomycin and daptomycin by disc diffusion test as per CLSI guidelines 2021.
 Conclusion: To conclude, MRSA plays a significant role and it can be transmitted through endogenous, cross-infection and reinfections. Phenotypic methods like use of cefoxitin disc (30µg) can be considered for detection of methicillin resistance in S. aureus, as it consumes less time and easy to perform.

Antibiotic Susceptibility Profiles of Bacterial Isolates Recovered from Abscesses in Cattle and Sheep at a Slaughterhouse in Algeria.

Abscesses represent the most prominent emerging problem in the red meat industry, leading to great economic constraints and public health hazards. Data on etiological agents present in these purulent lesions in Algeria are very scarce. The aim of this study was to identify the bacteria responsible for these abscesses and to determine their antibiotic susceptibility profiles. A total of 123 samples of abscesses from 100 slaughtered sheep and 23 slaughtered cattle were cultured in several media. A total of 114 bacterial isolates were cultured from 103 abscesses. Bacteria were identified using MALDI-TOF, and antibiotic susceptibility was determined by the disk diffusion method on Mueller-Hinton agar. A total of 73.6% (n = 84) corresponded to Enterobacterales, of which four were multidrug-resistant (MDR). These isolates, together with Staphylococcus aureus, coagulase negative Staphylococci, and seven randomly chosen susceptible Escherichia coli isolates, were further characterized using WGS. Resistome analysis of the four MDR Enterobacterales isolates revealed the presence of OXA-48 carbapenemase in two Klebsiella pneumoniae ST985 and one E. coli ST10 isolates and a CTX-M-15 ESBL in one E. coli isolate ST1706. Two coagulase-negative Staphylococci isolates were found to carry the mecA gene. WGS showed the presence of different resistance genes and virulence genes. Our study revealed 5% of MDR Enterobacterales (including ESBLs and carbapenemases) identified from abscesses, thus urging the need for abscess monitoring in slaughterhouses.

A Comparative Evaluation of Antimicrobial Efficacy of Various Intracanal Medicaments (Curcuma longa, Honey, Nitrofurantoin, and Calcium Hydroxide) on Enterococcus faecalis: An in vitro Study

Background In the modern era of dentistry, natural and herbal alternatives are favored since they are renewable, have fewer adverse effects, and are cost-effective. Purpose To assess the effectiveness of different intracanal medications in eliminating Enterococcus faecalis. Materials and Methods In total, 50 single-rooted extracted teeth were decoronated at the cemento-enamel junction followed by the preparation of the canal. Then, in each of the presterilized samples, inoculum containing the E. faecalis was transferred and incubated at 37°C for 24 hours. Samples were allocated into 5 groups of 10 each: Group A (saline), Group B (calcium hydroxide), Group C ( Curcuma longa), Group D (honey), and Group E (nitrofurantoin group). The medicaments were injected into the canals respectively, the antibacterial assessment was done on the 1st and 7th day. Dentinal shavings are incubated and streaked on Mueller–Hinton agar plates and incubated for 24 hours at 37°C and the colony forming units (CFUs) were assessed. Results Among all the groups, there was a significant change in the number of colonies from Day 1 to Day 7, except in Group A (saline). Comparison between the groups revealed significant differences, with better efficacy by Group D (honey) followed by Group E (nitrofurantoin) and Group C ( C. longa). The least antimicrobial efficacy was observed with calcium hydroxide and no activity with saline. Conclusion Honey has the greatest antimicrobial efficacy among all the tested intra-canal medicament groups.