Kirby-Bauer Method Research Articles

The Impact of Metal and Heavy Metal Concentrations on Vancomycin Resistance in Staphylococcus aureus within Milk Produced by Cattle Farms and the Health Risk Assessment in Kurdistan Province, Iran.

In today's food landscape, the paramount focus is on ensuring food safety and hygiene. Recognizing the pivotal role of the environment and its management in safeguarding animal products, this study explores vancomycin resistance in raw milk from livestock farms in the Kurdistan province and its correlation with metal and heavy metal. One hundred and sixty raw milk samples were collected from various locations, with heavy metal concentrations analyzed using ICP-MS. Identification of Staphylococcus aureus and vancomycin resistance testing were conducted through culture and the Kirby-Bauer method. This study investigates the relationship between resistance and heavy metal levels, revealing that 8.75% of milk samples contained Staphylococcus aureus, with 28.58% exhibiting vancomycin resistance. Significant variations in arsenic, iron, zinc, sodium, and aluminum concentrations were observed between resistant and sensitive samples (p < 0.01). The increase in arsenic, iron, and aluminum, along with the decrease in zinc, demonstrated a significant association with vancomycin resistance (p < 0.001). Levels of lead, cadmium, mercury, zinc, and iron exceeded permissible limits (p < 0.05). The Target Hazard Quotient (THQ) for cadmium indicated a high non-carcinogenic risk, while the Target Risk (TR) for arsenic fell within the carcinogenic range. Accumulation of heavy metals has the potential to impact antibiotic resistance in milk, underscoring the imperative to control arsenic residues for national safety.

ESSENTIAL OILS FROM Melaleuca leucadendra AND Pogostemon cablin Benth AS ACTIVE IN HAND SANITIZER WITH ANTIBACTERIAL AND ANTIVIRAL PROPERTIES

In addition to giving a pleasant scent, essential oils in hand sanitizer formulation could contribute to the increase on its efficacy. Herein, we aimed to evaluate the antioxidant, antibacterial, as well as antiviral activities of eucalyptus oil (EO) and patchouli oil (PO), followed by their application in hand sanitizer formulation. Essential oils were obtained from a simple distillation and followed by fractionation using a rotary evaporator. Antioxidant activities of the essential oils were determined based on a DPPH scavenging assay. The antibacterial activities against Staphylococcus aureus as well as Escherichia coli were evaluated under the Kirby-Bauer method. The antiviral activities of EO and PO were based on the replication inhibition of Simian retrovirus-2 (SRV-2) in an A549 cells model. Our data suggest that the fractionation increases the purity of EO and PO based on the content of 1,8-cineole (from 54.08% to 85.05%) and patchouli alcohol (from 29.28% to 85.01%), respectively. IC50 values of fractionated EO and PO in DPPH scavenging activity were 131.21 and 118.20 ppm, categorized as moderately active antioxidants. The optimum inhibition zones against S. aureus along with E. coli were achieved by fractionated EO (10.49 and 15.79 mm, respectively). SRV-2 replication could be effectively attenuated even until day-7 post-infection. When applied in hand sanitizer formulation (in a small amount), only antibacterial activity against E. coli was found higher as compared with usual hand sanitizer. Moreover, in hand sanitizer formulation, the efficacy of antiviral activity against SRV-2 was reduced to only last for 5 days post-infection. EO and PO can be used as active ingredients in hand sanitizer formulation owing to their antibacterial, antiviral, and antioxidant activities.

Identification of beta-lactamase genes in Nitrofurantoin-resistant gram-negative bacteria isolated from pregnant women using molecular techniques

The predominant infection among pregnant women is urinary tract infection (UTIs), which may lead to various complications. So, this investigation was to detect gram-negative UTIs isolates and beta-lactam resistance genes. The study included 100 (28.57%) inpatient pregnant women and 250 (71.42%) outpatient pregnant women treated at Al-Zahraa teaching hospital for children’s health and maternity, Al-Najaf City, Iraq. Finding showed that The majority of the age group was 31-40 years old which involved 80 (22.85%) growth and 45 (12.85%) no growth. Results also showed the high rate of bacteria among pregnant women in third-trimester was 127 (36.28%). According Kirby-Bauer methods, only 33/150 (22%) of gram-negative isolates were nitrofurantoin-resistant. Results of PCR amplification showed that all 33 out of 33 (100%) gram negative isolates had the ctx-m gene. Additionally, a significant prevalence of AmpC gene was discovered in 32 out of 33 isolates (96.96%). The veb gene, on the other hand, was only detected in P. aeruginosa isolates, with a prevalence of 1 out of 33 (3.03%). The PCR findings revealed the presence of oxa-like 5 genes in 12.12% (4/33) of the isolates. Although oxa-69 was not identified in this study.

Prevalence of Extended‐Spectrum Beta‐Lactamase Producer Gram‐Negative Rods and Associated Factors Among Patients With Wound Infection at University of Gondar Comprehensive Specialized Hospital, Northwest Ethiopia

Background: Multidrug‐resistant (MDR) bacteria have significantly affected the management and treatment of wound infections globally. Data on the prevalence of MDR bacterial profiles that cause wound infections in Ethiopia are scarce. Therefore, this study aimed to determine MDR as well as extended‐spectrum beta‐lactamase production profiles of Gram‐negative rods that are difficult to treat with conventional antibiotics and that cause wound infections.Objective: The aim of the study was to determine the prevalence of extended‐spectrum beta‐lactamase producer Gram‐negative rods and associated factors among patients with wound infection at University of Gondar Comprehensive Specialized Hospital, northwest Ethiopia.Materials and Methods: This hospital‐based cross‐sectional study was conducted at University of Gondar Comprehensive Specialized Hospital between May and July 2022. Convenience sampling was used to recruit 228 participants. Swabs from different wound types were inoculated onto the MacConkey agar and blood agar plates and incubated overnight at 37°C for 24 h. Biochemical tests were performed on isolated colonies for the identification of bacterial species based on their biochemical reaction. Antimicrobial susceptibility tests were performed using the disk diffusion technique as per the standard Kirby–Bauer method by using Muller–Hinton agar, and the zone of inhibition was interpreted as resistant, intermediate, and sensitive as per the recommendation of Clinical Laboratory Standard Institute. Isolates were tested against ceftriaxone, cefotaxime, and ceftazidime for extended‐spectrum beta‐lactamase screening using the Kirby–Bauer disk diffusion method, and combined disk tests were applied for phenotypic confirmatory test of extended‐spectrum beta‐lactamase producing isolates.Result: Of 228 study participants, 162 (71.1%) were culture‐positive. Among culture‐positive patients, 165 Gram‐negative bacteria were recovered. The most common Gram‐negative isolates were Pseudomonas aeruginosa (47; 28.5%), followed by Escherichia coli (43; 26.1%) and Klebsiella pneumoniae (24; 14.5%). The susceptibility rates of the isolate for imipenem and tobramycin were 97.0% and 73.2%, respectively, and the overall multidrug resistance rate was 80.5%. Extended‐spectrum beta‐lactamase producer bacteria were also isolated. Besides, all (100%) of extended‐spectrum beta‐lactamase producer bacteria were MDR. Living in rural areas (AOR 5.8; 95% CI [2.01–16.7]), hospital admission (AOR 3.95; 95% CI [1.13–13.83]), antibiotic use (AOR 2.83; 95% CI [1.03–7.72]), and comorbidity (AOR 0.25; 95% CI [0.07–0.59]) were significantly associated with wound infection.Conclusions and Recommendations: There was a high prevalence of Gram‐negative bacterial isolates in this study. Pseudomonas aeruginosa (28.5%) was the predominant isolate. In addition, high rates of multidrug resistance were observed. The high level of multidrug resistance in this study implies that definitive therapy should be based on culture and susceptibility analysis to promote the rational use of antibiotics and to reduce the emergence of bacterial resistance to antimicrobials.

Molecular study of antibiotic resistance gene among nitrofurantoin-resistant gram-negative bacteria isolates from pregnant women

In pregnancy, urinary tract infection (UTIs) is a significant risk factor for morbidity, and nitrofurantoin is a common UTI therapy. The goal was to identify gram-negative UTI isolates and detect antibiotic resistance genes. The research involved 350 pregnant women hospitalised to Al-Zahraa teaching hospital for children’s health and maternity between September and December 2024. Out of 250 pregnant patients, 200 (57.14%) urine samples were bacterial-free, whereas 150 (42.86%) were positive for gram-negative bacteria. The findings showed that 105 isolates (70%) were Escherichia coli, 33 (22%) were Klebsiella pneumoniae, 8 (5.3%) were Pseudomonas aeruginosa, 3 (2%) were Proteus mirabilis, and 1 (0.7%) were Acinetobacter baumannii. The disc diffusion Kirby-Bauer method determined 150 (100%) gramme negative bacteria’s nitrofurantoin sensitivity. 33 (22%) isolates were antibiotic-resistant, 16 (10.66%) intermediate, and 101 (67.33%) susceptible. PCR analysis showed that all 33 out of 33 (100%) gram negative isolates had Ribe, and AcrAB genes. Additionally, a significant prevalence of nfsA-2 genes was discovered in 32 out of 33 isolates (96.96%) the nfsA-1 gene in 78.78% (26/33) of the isolates. The NfsB gene was detected in 30 out of 33 (90.90%) distinct isolates of nitrofurantoin-resistant gram-negative bacteria. The Nucleic acid and amino acid sequence study of NfsA and Ribe genes in some local isolates of K. pneumoniae reveals variations in sequence when compared to other global strains with the same genes.

Evaluación de la actividad antimicrobiana de la bebida de kéfir contra escherichia coli, salmonella typhimurium y shigella flexneri

Objective: Evaluate the antimicrobial activity of the Kefir drink against Escherichia coli, Salmonella typhimurium and Shigella flexneri Method: The Kefir used in the investigation was acquired in Toluca, State of Mexico. We performed a reactivation of Kefir with pasteurized milk and analyzed 3 carbohydrates (honey, sugar and piloncillo) at different concentrations and times, 80, 100, 120% and 24, 48 and 72 hours respectively. Isolated cultivable microorganisms were characterized by phenotypic, biochemical and mass spectroscopy techniques. The initial and final pH were determined during the study time. The antimicrobial activity was carried out by extracting the metabolites present in the ferment with the Kirby-Bauer method, in addition the direct ferment was evaluated, to determine if there was inhibition with the Escherichia coli (ATCC 11229) strains, Salmonella typhimurium (ATCC 14028) and Shigella flexneri (ATCC 12022). Results: It was observed that in the three carbohydrates used at a concentration of 120% and at a time of 72 h, a lower pH was obtained (3.51 to 3.64) compared to their initial concentration (6.50 to 6.64). From the metabolites extracted in the different ferments, no inhibition halo was obtained with the strains analyzed. However, when using direct ferments, it was observed that in the carbohydrates used (sugar, honey, piloncillo) there was the presence of an inhibiting halo or the growth of colonies other than those evaluated. The isolated cultivable microorganisms were: Pichia kudriavzevii (yeast); Enterococcus sp (gram-positive coconut) and Lactobacillus sp (gram-positive bacillus). Conclusions : Kefir ferments made with different carbohydrates, came to present a degree of inhibition only as a consortium against Gram-negative microorganisms analyzed. Keywords: Kefir; fermentation microbiota; infection; antimicrobial activity

Antibiotic Resistance in Escherichia Coli Bacteria Isolated from Water Sources and Waste Disposal in Livestock Farms in East Lombok

Poor antimicrobial stewardship in livestock farms will lead to the emergence of bacterial resistance to antibiotics. Dug wells as a water source and waste disposal on livestock farms have a close distance, allowing transmission of Escherichia coli-resistant bacteria through soil absorption and fecal contamination. This study aims to isolate Escherichia coli from water sources and livestock waste disposal in East Lombok Regency and determine their sensitivity to several antibiotics. The type of this research is a descriptive cross-sectional survey using four water wells and four waste disposals with a criterion of &lt; 10m range. Escherichia coli bacteria were isolated using culture techniques on Eosin Methylene Blue Agar, and identification was carried out using gram staining and biochemical tests. Determining sensitivity to antibiotics was performed using the Kirby-Bauer disk-diffusion method. The results showed that Escherichia coli bacteria have been isolated from water sources and waste disposal on livestock farms in East Lombok Regency. 100 % Escherichia coli isolates sensitive to Gentamicin, Ciprofloxacin, and Cefotaxime. 87.5% Escherichia coli isolates sensitive to Oxytetracycline, 12.5% ​​Escherichia coli isolates resistant to Oxytetracycline, 100% Escherichia coli isolates resistant to Penicillin G. Escherichia coli bacteria isolated from water sources and waste disposal at a livestock farm in East Lombok.

Evaluation of antimicrobial activity of biomaterials based on alginate and decametoxin against Staphylococus aureus and Escherichia coli

The aim was to study the antimicrobial activity of new biomaterials based on decamethoxine and commercially available wound dressings against reference and clinical strains of S.aureus and E.coli. Materials and methods. Developed biomaterials with 0.05 % decamethoxine (DCM No. 1-3) and wound dressings containing antiseptics Suprasorb®, SILVERCEL®, Urgotul SSD®, GUANPOLISEPT®, Bétadine® were used for the study. Antimicrobial properties were studied by zone of inhibition (ZOI) testing using the Kirby-Bauer method. Results. In relation to S.aureus ATCC 25923, a significantly higher antimicrobial activity of biomaterials with DCM compared to silver- and iodine-containing wound dressings was found to be 1.97-2.11 (p &lt;0.001) and 1.73-1.86 times (p &lt;0.001), respectively. Similar activity against S.aureus ATCC 25923 was possessed by all three samples with DCM (ZOI - from 21.98±0.18 to 23.58±0.26 mm) and Suprasorb® (19.31±0.17 mm), Guanpolisept® (19.13±0.12 mm). Such a tendency was also found in relation to clinical strains of staphylococci. A high level of activity against E.coli ATCC 25922 was shown by biomaterials No. 1-3 DCM (ZOI - from 19.01±0.33 to 21.54±0.23 mm), Guanpolisept® (18.74±0.12 mm) and Suprasorb® (18.43±0.13 mm). Clinical strains of E.coli showed greater tolerance to antimicrobial biomaterials: the difference in mean values between the ZOI of the reference and ZOI of clinical strains of E.coli was significant for all biomaterials (p &lt;0.001). The most effective were biomaterials with DCM No. 1-3 (ZOI - from 15.58±0.25 to 16.41±0.16 mm), as well as Suprasorb® (15.82±0.31 mm). Conclusions. Biomaterials based on decamethoxine No. 1, No. 2, No. 3, Suprasorb®, Guanpolisept®, and Bétadine® have the highest antistaphylococcal activity. Biomaterials with decamethoxin No.1-3, Suprasorb® and Guanpolisept® show the strongest effect on reference and clinical strains of E.coli

Antibiotic Resistance of Bacillus cereus in Plant Foods and Edible Wild Mushrooms in a Province.

Bacillus cereus is a common pathogen causing foodborne diseases, secreting and producing a large number of toxins that can cause a variety of diseases and pose many threats to human health. In this study, 73 strains of Bacillus cereus were isolated and identified from six types of foods from seven different cities in a province, and the antibiotic-resistant phenotype was detected by using the Bauer-Kirby method. Results showed that the 73 isolates were completely sensitive to gentamicin and 100% resistant to chloramphenicol, in addition to which all strains showed varying degrees of resistance to 13 other common antibiotics, and a large number of strains resistant to multiple antibiotics were found. A bioinformatic analysis of the expression of resistance genes in Bacillus cereus showed three classes of antibiotic-resistant genes, which were three of the six classes of antibiotics identified according to the resistance phenotype. The presence of other classes of antibiotic-resistant genes was identified from genome-wide information. Antibiotic-resistant phenotypes were analyzed for correlations with genotype, and remarkable differences were found among the phenotypes. The spread of antibiotic-resistant strains is a serious public health problem that requires the long-term monitoring of antimicrobial resistance in Bacillus cereus, and the present study provides important information for monitoring antibiotic resistance in bacteria from different types of food.

Antibacterial, antifungal and antioxidant activities of Bacillus cereus SMPRL-2 isolated from seaweeds Eucheuma cottonii

Seaweeds have a strong relationship with prokaryotic community especially bacteria. Bacteria-associated with seaweeds generally produce active compounds which could be potential for pharmaceutical purposes. This research was focused to study antibacterial, antifungal and antioxidant activities from a bacteria encoded as SMPRL-2, isolated from Eucheuma cottonii. Molecular identification of the isolate was performed based on 16S rRNA sequencing and its morphology was assessed using scanning electronic microscope (SEM). The isolate SMPRL-2 was fermented in 100 mL ISP-2 liquid media for 14 days and extracted using ethyl acetate (1:1 ratio, v/v). The obtained crude extract was screened against bacterial and fungal isolates based on Kirby-Bauer method. The extract was screened for its antioxidant activities using DPPH method. The isolate was identified as Bacillus cereus, with short rod morphology under SEM observation. Zone of inhibition (ZOI) of the extract was 14.7±0.8 mm and 9.1±0.8 mm against Streptococcus mutans FNCC 0405 and Escherichia coli ATCC 25922, respectively. Furthermore, ZOI of the extract against Candida albicans and Aspergillus flavus were 9.6±0.9 mm and 8.8±2.3 mm respectively. A very weak antioxidant activity with IC50 value of 33000 ppm was observed. Overall, this result provides a preliminary finding of marine bacteria as naturally active compounds producer.

Inhibition of Lactobacillus acidophillus, Lactobacillus, Bacteria plantarum and Bifidobacterium spp. against Escherichia coli and Salmonella sp. in the digestive tract in vitro

The bacteria Lactobacillus acidophillus, Lactobacillus plantarum and Bifidobacterium spp. is a lactic acid bacteria that is used as a probiotic. The research was conducted with the aim of knowing the inhibition of the pribiotic bacteria Lactobacillus acidophillus, Lactobacillus plantarum and Bifidobacterium spp. against Escherichia coli and Salmonella sp. Supporting tests such as motility tests, catalase tests, and fermentation tests were also carried out. The media used in this study were: Mueller Hinton Agar (MHA) with the Kirby-Bauer method and Nutrient Broth (NB) media, TSIA, SIM. The control groups used in this study were P1 : Lactobacillus acidophillus, P2 : Lactobacillus plantarum, P3 : Bifidobacterium, P4 : Lactobacillus acidophilus + Bifidobacterium, P5 : Lactobacillus plantarum + Bifidobacterium, P6 : Lactobacillus acidophilus + Lactobacillus plantarum + Bifidobacterium, and P0 as control. The greatest inhibitory power on Escherichia coli bacteria was at P3, P4, P6 at 0.30 mm and Salmonella sp. namely at P4 by 15 mm. While the smallest inhibition on Escherichia coli bacteria is at P5, P7 is 0.2 mm and Salmonella sp. namely at P3, P5, P6 by 0.25 mm.

Frequency and Antimicrobial Resistance Patterns of Foodborne Pathogens in Ready-to-Eat Foods: An Evolving Public Health Challenge

Food products that are ready-to-eat have become increasingly popular in recent years due to their efficiency, affordability, and convenience. However, there are concerns about public health because certain products, particularly animal products, may contain antibiotic-resistant bacteria. This study aimed to quickly and accurately identify foodborne pathogens, such as Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), in samples of shawarma and chicken burgers using peptide mass fingerprinting (PMF) technology. Additionally, the prevalence and levels of antibiotic resistance in the pathogens were determined. The study utilized 300 samples obtained from fast food restaurants in Al Qassim, Saudi Arabia. A variety of methods were used to identify foodborne pathogens, including culture on specific media, bacterial counts by numerical dilutions of homogenized samples, and proteome identification by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The Kirby–Bauer method was applied to detect the susceptibility and resistance of the bacteria to various antibiotics. PCR was utilized to identify antimicrobial resistance genes such as blaTEM, tet(A), blaZ, and mecA in S. aureus and E. coli isolates. The percentage of E. coli, S. aureus, Salmonella, Listeria monocytogenes (L. monocytogenes), Acinetobacter baumannii (A. baumannii), and Hafnia alevei (H. alevei) was 34%, 31%, 10.67%, 7.33%, 6.67%, and 4%, respectively. Shawarma samples were found to contain the highest levels of pathogens, compared with chicken burger samples. According to the MBT Compass Flex Series Version 1.3 software, all isolates were identified with 100% accuracy. The log score for MBT identification ranged from 2.00 to 2.56. Among E. coli isolates, ampicillin, and penicillin had the highest resistance rate (100%), followed by tetracycline (35.29%). A number of antibiotics were reported to be resistant to S. aureus, including nalidixic acid (100%), followed by penicillin (96.77%), piperacillin (45.16%), and norfloxacin (32.26%). Some E. coli isolates were susceptible to tetracycline (49.02%), nalidixic acid (47.06%), and piperacillin (43.14%), whereas amikacin was the only drug that was effective against 32.72% of S. aureus isolates. The proportions of the blaTEM and tet(A) genes in E. coli isolates were 55.89% and 45.1%, respectively, whereas S. aureus strains did not possess either of these genes. However, 21.5% and 47.31% of blaz and mecA genes were present among various isolates of S. aureus, respectively. In contrast, E. coli strains did not possess either of these genes. In conclusion, the fast identification and antimicrobial profiles of the foodborne pathogens were useful in identifying which restaurants and fast food outlets may need to improve their food safety practices. Ultimately, our results will be used to devise targeted strategies to control foodborne pathogens.

Effect of different face washes on the bacterial pathogens of skin

Pathogens like Propionibacterium acnes, Staphylococcus aureus, E. coli, and Candida species are kept at bay by the skin's natural flora. There are face washes and cleansers on the market now that eliminate specific skin germs and keep healthy skin infection-free. Each volunteer's face was used to take a sample, the sample was taken by gently scraping every surface of the participant's face, including the popped-up Acne, using a sterile swab dipped in normal saline. The gathered samples were cultured on Nutrient Agar, and the organisms that had developed there were recognised by Gram staining and the appropriate biochemical identification and placedin different levels. The organism was then put to the test against several isolated organisms using a sensitivity test (Kirby-bauer Method) using diluted versions of 5 different face washes. Staphylococcus aureus, Micrococcus spp., Bacillus spp., E. coli, and Klebsiella spp., were among the predominant strains among the 40 different strains that were recovered from the 40 different volunteers .The antimicrobial effects of five commercially available face washes Vicco, Cetaphil, Himalayas, Neem and Tulsi and Ponds were tested on the isolated organisms at dilutions of 1:10. When compared to other face washes, HIMALAYA has the strongest antibacterial activity and the second- highest maximum zone of inhibition against the following microorganisms: Staphylococcus aureus, Micrococci spp., and Klebsiella spp., According to the experiment, face washes PONDS and CETAPHIL have the least antibacterial activity, no zone of inhibition, and are resistant to all five detected organisms.

Green Synthesis of Silver and Copper Nanoparticles using Lemon pulp: Antibacterial and Antidiabetic activity

Diabetes mellitus is a complex and chronic metabolic disorder which has a critical impact on the body’s ability to utilize the energy acquired found in food. A major symptom of diabetes is hyperglycemia. In all types of diabetes mellitus, human body does not make enough insulin or it cannot utilize the insulin it produces. In this study we are using pulp extract of Citrus limon and preparing silver and copper nanoparticles. We have evaluated the antibacterial and antidiabetic activity with E.coli and Staphylococcus culture using Kirby bauer, α-amylase and glucose transfer method. The characterization of the nanoparticles is done by the Fourier Transform Infrared Spectroscopy (FTIR), dynamic light transfer test, scanning electron microscope.

Comparison of Antimicrobial Effectiveness of Orange and Lime’s Extracts on Aeromonas sobria and Aeromonas hydrophila

Aeromonas bacteria are often found in aquatic environments and can be isolated from various types of fish. Globally, the incidence of infection by Aeromonas reached 0.6–76 cases per 1 million people. Orange and lime are generally used as cooking spices to get rid of the fishy smell in fish, and also have antibacterial effects. The study compared the antibacterial effectiveness of lime and orange extracts on two Aeromonas species; A. sobria and A. hydrophila. Bacteria Aeromonas may emerge from fresh tuna bought in traditional markets. Lime and orange extracts were prepared using the maceration method using 96% methanol as solvent. The extract concentrations used were 6.25%, 12.5%, 25%, and 50%. Antimicrobial sensitivity test was carried out using the Kirby-Bauer method. The bacterial inhibition zone test revealed that the effectiveness of extracts on both oranges and limes was higher for the bacteria A. hydrophila compared to A. sobria. It is known from the average diameter of the inhibition zone, which is larger on A. hydrophila compared to A. sobria, except for the extract with a concentration of 6.25% orange and 50% lime. In a comparison between extracts, lime extract was found to be more effective as an antimicrobial than orange extract, except at a concentration of 6.5% in the bacterial test A. sobria and 50% concentration in the bacterial test A. hydrophila. In general, lime is more effective as an antimicrobial than orange.

Deteksi Escherichia coli Resisten Antibiotik pada Sumber Air dari Lingkungan Peternakan Unggas di Kecamatan Kelapa Lima Kota Kupang”

Clean water is water that can be used for daily purposes whose quality meets health requirements and can be drunk if it has been cooked. The source of origin of the spread of resistant bacteria in addition to human and environmental origin has been reported to also come from animal husbandry. The presence of antibiotic-resistant bacteria such as Escherichia coli on farms is a threat to the health of farm animals and humans around the farm area. This studyaims to obtain information about the percentage of E. coli and the incidence of antibiotic resistance in E. coli bacteria isolated from water sources in the poultry farming environment in Kelapa Lima District, Kupang City. A total of 30 water source samples were taken by purposive sampling method, out of 30 samples 16 positive samples of E. coli were found. Samples are tested to obtain E. coli isolates supported by identification test examinations with biochemical tests and subsequently tested their sensitivity patterns to antibiots. The study was conducted by the Kirby-Bauer method. The type of antibiotic used in this study is based on the type of antibiotic in EFSA (2012) used in the monitoring of Resistant Antimicrobials (AMR) for Salmonella spp and E. coli through food. This guide suggests using a class of antibiotics commonly used in the treatment of bacterial infections in animals as well as humans. The interpretation of the results of this sensitivity test refers to the Clinical and Laboratory Standards Institute (CLSI 2012). The results of this study showed that as much as 53.3% (16/30 samples) of the water population in the poultry farming environment in Kelapa Lima District, Kupang City contained E. coli and obtained a percentage of E. coli that was resistant to tetracycline antibiotics, which was 6.25% (1/16 sample).

A Perusal of Phenolics Within Polar Peel Fractions of Malus domestica var Maharaji via Hyphenated Techniques Cum Anti-microbial with REMA and Tyrosinase Inhibitory Potential thereof

This study aims to scrutinize the phenolic secondary metabolites in the polar peel decocture of Malus domestica var Maharaji via hyphenated techniques along with the study of the antibacterial, anti-candida, and tyrosinase inhibitory potential of bioactive compound-rich fractions. Preliminary phenolics go over was performed together with thin layer chromatography before the polar decocture was subjected to hyphenated techniques. FTIR investigation revealed the C-O bonds as in phenols, O-H bond stretch, and vibrations of alcohols and carboxylic acids as well as portrayed the C-H and &gt;C=O stretches among other functional groups all of which are representative of phenolic and polyphenolic compounds. GC-MS perusal demonstrated the presence of bioactive compounds like Quercetin (13.04%), Ascorbic acid (6.48%), p-Coumaric acid (6.17%), Caffeic acid (5.69 %), Mallic acid (5.44%), Apigenin (5.28%), Citric acid (5.15%), Gallic acid (4.38%), Cyanidin (3.52%), and Ferulic acid (3.51%). Kirby-Bauer method followed by the resazurin microtiter assay technique (REMA) for MIC/MBC against six MTCC bacterial strains and one yeast, all producing stubborn opportunistic infection in humans, was used to assess the antibacterial property of all the bioactive rich fractions. Some fractions comparatively revealed a good activity index (AI) against tested microbes. MIC concentrations for bacteria ranged from 15-24 mg/ml while a lower MBC value recorded was 18 mg/ml. Methanol fraction revealed significant tyrosinase inhibitory activity by revealing IC50 of 980.98 µg/ml when L-Tyrosine was substrate and IC50 of 830.68 µg/ml when L-DOPA was substrate when juxtaposed to standard kojic acid that revealed IC50 of 128.822 µg/ml when L-Tyrosine was substrate and IC50 of 149.43 µg/ml when L-DOPA was substrate. The bioactive compounds possessed by the fractions, may be synergistically, turned out to be more effective in the diphenolase reaction and kojic acid acts more effectively in the monophenolase one. It was inferred that peel phenolics of this malus variety have a lot of therapeutic potential in the context of bacterial infections and pigmentation disorders.

Effect of silver nanoparticles on the morphological, antibacterial activity and performance of graphene oxide-embedded polyvinylidene fluoride membrane

In this work, a different ratio of silver nanoparticles (Ag NPs) was used as a nanofiller on graphene oxide (GO)-embedded polyvinylidene fluoride (PVDF) membranes fabrication through a non-solvent induced phase separation method. The morphology of fabricated membranes was investigated using FTIR, XRD, and SEM-EDX techniques. The fabricated membranes were tested for Bovine Serum Albumin (BSA) rejection and Molecular Weight Cut Off (MWCO) with various initial concentrations of 100 – 400 ppm and 6 – 145 kDa, respectively using a crossflow method, as well as antibacterial activity against four strains bacteria via total plate counting and Kirby-Bauer method. The incorporation of hydrophilic GO and Ag NPs obviously alters membrane morphology, enhances membrane’s porosity and hydrophilicity. Moreover, it improves membrane crystallinity (> 70%) as indicated by the higher XRD peaks intensity. Based on the crossflow measurements, the membrane fabricated with GO and Ag ratio of 1: 3 (PVDF/GO/AgNPs – 3) demonstrated the highest BSA flux of 83.81 L/m2 h, which was third-fold higher than that of PVDF membrane as well as high BSA rejection (> 94%) and MWCO of ∼3 kDa. According to the observation, PVDF/GO/AgNPs – 3 also possessed a high bacteria killing ratio of > 94% and a large inhibition zone of ≥ 1.5 mm toward all bacteria strains. These results inferred that PVDF/GO/Ag membrane has great potential as antibiofouling membranes.

Screening of Undaria pinnatifida (Laminariales, Phaeophyceae) Lipidic Extract as a New Potential Source of Antibacterial and Antioxidant Compounds

The lipidic extract of Undaria pinnatifida, one of the worst invasive species, was investigated for its potential exploitation in biotechnological applications. The antimicrobial activity of the lipidic extract in three different portions (blade, sporophyll, and holdfast) was assessed by using the Kirby–Bauer method, while the antioxidant activity was evaluated by the TEAC, ORAC, and Folin–Ciocalteu assays. NMR spectroscopy and thin-layer chromatography were employed for the chemical characterization. The extracts showed antibacterial activity against several of the tested Vibrio species: V. aestuarinus, V. fischeri, V. furnisii, V. inusitatus, V. litoralis, and V. mediterranei, including some pathogens for farmed fish. Intriguing antioxidant activity was recorded, with the highest value in the blade (126.907 ± 28.993 mmol Trolox equivalent/g TEAC). Free, saturated, unsaturated, and polyunsaturated fatty acids were highlighted by 1D and 2D NMR spectroscopy. The presence of ω-3 and ω-6 PUFAs indicates the importance of this algal species in the food industry. We suggest the employment of U. pinnatifida as source of new and safer therapeutic agents to control fish and shellfish diseases due to vibriosis, as well as a source of natural antioxidants that are useful for human health, considering the growing interest in the development of strategies for invasive seaweed control.

Identification of Vibrio metschnikovii and Vibrio injensis Isolated from Leachate Ponds: Characterization of Their Antibiotic Resistance and Virulence-Associated Genes.

This study aimed to evaluate the antibiotic resistance of 22 environmental Vibrio metschnikovii isolates and 1 Vibrio injensis isolate from landfill leachates in southwestern Colombia. Isolates were identified by Matrix-Assisted Laser Desorption/Ionization-Time-Of-Flight (MALDI-TOF), and 16S ribosomal RNA gene sequencing. Analysis of the susceptibility to six antibacterial agents by the Kirby-Bauer method showed susceptibility of all the isolates to ciprofloxacin and imipenem. We recorded resistance to beta-lactams and aminoglycosides, but no multidrug resistance was observed. The genome of one of the isolates was sequenced to determine the pathogenic potential of V. injensis. Genes associated with virulence were identified, including for flagellar synthesis, biofilm formation, and hemolysins, among others. These results demonstrate that landfill leachates are potential reservoirs of antibiotic-resistant and pathogenic bacteria and highlight the importance of monitoring Vibrio species in different aquatic environments.