Disk Diffusion Susceptibility Research Articles

P-2214. The Microbiome of Community-Dwelling Adults and Risk Factors for Colonization with Antibiotic-Resistant Bacteria in Chile

Abstract Background Intestinal colonization due to antibiotic-resistant bacteria (ARB) often precedes episodes of infection and fosters the spread of antibiotic resistance. This study explores the clinical, epidemiological, and microbiome factors associated with ARB colonization in Chilean adults. Methods A cross-sectional study of 357 community-dwelling individuals from a community in central Chile was conducted between December 2018 - May 2019, using stool samples and health questionnaires. Stool samples were cultured on selective media, followed by identification with MALDI-TOF and disc diffusion susceptibility method. Fecal microbiome assessments were conducted using 16S rRNA gene sequencing performed on Illumina MiSeq. ARB colonization was defined as phenotypic resistance of recovered isolates to extended-spectrum cephalosporins, fluoroquinolones, and/or carbapenems. Associations between colonization and clinical and epidemiological factors were analyzed through classification trees and logistic regression, while diversity and composition of microbiomes were compared between participants based on colonization status. Results No exposures were associated with the risk of ARB colonization. The microbiomes of colonized individuals featured Firmicutes, with Bacteroidetes, Actinobacteria, and Proteobacteria also present, paralleling the microbiome profile of the non-colonized individuals. However, ARB-colonized individuals had an overrepresentation of Escherichia/Shigella, Klebsiella, and Enterococcus genera. There were no differences in alpha or beta diversity by ARB colonization status. Conclusion The lack of risk factors regarding ARB colonization suggests that such colonization might occur without overt selective pressures. However, the overrepresentation of specific genera in colonized individuals could subtly indicate the influence of unrecognized selective pressures, such as environmental exposure to antibiotic residues. This scenario underscores the complexity of ARB dynamics and the need for further studies to explore potential environmental and indirect factors contributing to ARB colonization in the community setting. Disclosures All Authors: No reported disclosures

302. A Randomized Controlled Trial of Rapid Pathogen and Resistance Identification from Positive Blood Cultures

Abstract Background Morbidity from bacteremia may be exacerbated by inadequate initial antibiotic therapy. This concern however may lead to hesitance to de-escalate while awaiting pathogen identification and susceptibility results. We performed a randomized controlled trial evaluating the impact of a strategy for rapid pathogen and resistance detection directly from positive blood culture bottles (BCBs) using a rapid multiplex PCR (rmPCR) complemented with a rapid phenotypic screen (RPS) for extended-spectrum beta-lactamases and carbapenemases in a setting with moderate to high levels of antimicrobial resistance where routine direct-from-BCB disk diffusion susceptibility testing was in place Methods Patients with positive BCBs were randomized to 2 arms: 1) Standard BCB processing (including direct from BCB disk diffusion susceptibility testing - control, n=419) with antimicrobial stewardship (AS); or 2) rmPCR/RPS with AS (rmPCR/RPS, n=425). The primary outcome was time from positive blood culture result to prescription of an effective or optimal antibiotic regimen. An effective antibiotic regimen was defined as one active against the detected pathogen(s); an optimal antibiotic regimen was defined as an effective regimen which was also the most narrow spectrum and targeted one, as recommended by institutional guidelines. Mortality was analyzed as a secondary outcome. Results True bacteremia was identified in 658 patients (n=329 in both arms); 597 were monomicrobial (405 with aerobic or facultative anaerobic Gram negatives rods [AGNR]) and 61 polymicrobial (41 harboring AGNR). Time from BCB Gram stain to prescription of an effective antibiotic was 9.9 versus 3.2 hours in the control and rmPCR/RPS groups, respectively (p=0.58) and time from Gram stain to prescription of an optimal antibiotic regimen was 41.6 versus 29.4 hours in the two groups, respectively (p < 0.001). 14-day mortality was 7.6% versus 4.3% (p = 0.069) and 30-day mortality was 11.2% versus 8.8% (p=0.30) in the two groups, respectively. Conclusion Compared to control methods which included direct-from-BCB disk diffusion susceptibility testing, an intervention comprising rmPCR/RPS with AS applied to positive blood cultures improved time to optimal therapy but not time to effective therapy or mortality. Disclosures Shawn Vasoo, MBBS, MRCP, D(ABP), D(ABIM) (Inf Dis), FRCPath, bioMerieux: In-kind, for this study|Rosco Diagnostica: In-kind, for this study Robin Patel, MD, a patent on Bordetella pertussis/parapertussis PCR issued, a patent on a device/method for sonication with royalties paid by Samsung to Mayo Clinic, a: See above|MicuRx Pharmaceuticals and BIOFIRE: Grant/Research Support|PhAST, Day Zero Diagnostics, Abbott Laboratories, Sysmex, DEEPULL DIAGNOSTICS, S.L., Netflix, Oxford Nanopore Technologies and CARB-X: Advisor/Consultant|Up-to-Date and the Infectious Diseases Board Review Course.: Honoraria Paul Tambyah, MBBS (S'pore), Diplomate, American Board of Internal Medicine and Infectious Diseases, Moderna: Grant/Research Support|Sanofi-Pasteur: Grant/Research Support

P-2111. Automated Bacterial Growth Detection, Bacterial Species Estimation and Antimicrobial Susceptibility Testing on Agar Plates Using a Light Transmission-based Monitoring System

Abstract Background Culturing bacteria on agar plates is essential for diagnosing bacterial infections, but it usually takes overnight and is labor-intensive. We have developed a novel device using a thin-film transistor image sensor to measure light transmission through agar plates every five minutes during incubation (Nakada et al. ASM 2023 and IDweek 2023). Here we present a proof of concept study for using this device for automated early detection and disk-diffusion susceptibility testing and compare the results to those obtained by experienced microbiology technicians. Methods Chromogenic agar plates were used for early detection and subsequent species estimation based on colony color changes, i.e. Enterobacteriaceae on CHROMagar mSuper CARBA plates and Staphylococci on MDRS-K plates. Statistical background subtraction was used for early detection of bacterial growth and histogram comparison of pseudo-color images created by correcting the intensity of red, blue, and green lights for species estimation. For disk diffusion tests susceptible and resistant E. coli and S. aureus were inoculated on Mueller-Hinton plates against the known agents and incubated for 18 hours with monitoring. Transmitted light images after 18 hours were first binarized and the distance of the shortest bacterial growth pixel from the center of the corresponding antibiotic disk was measured as the inhibition zone diameter. Results The device detected Enterobacteriaceae and MRSA as early as 6 and 8 hours after incubation, respectively, when the suspensions were densely streaked (Figure 1). The device also estimated the bacterial species with sensitivity and specificity over 90% for Enterobacteriaceae, however, the specificity for MRSA against MRCNS was approximately 70% (Table 1). An example of the automated inhibition zone measurement is shown in Figure 2. All automated measurements agreed well with the manual measurements (Table 2). Conclusion The performance in the bacterial detection, species estimation and the zone diameter measurement indicated that the device can be useful in accelerating, automating, and standardizing routine testing in microbiology laboratories. Disclosures Goh Ohji, MD, Ph.D, CarbGem Inc.: Advisor/Consultant Masakazu Nakajima, B. Engineering, CarbGeM Inc.: Board Member|CarbGeM Inc.: Ownership Interest

Antimicrobial activity of Lactobacillus casei on Staphylococcus pseudintermedius isolates.

Antimicrobial resistance is increasing each year. For example, in 2019 it was directly responsible for an estimated >1 million deaths. Additionally, the development of new drugs is much slower, generating enormous concerns about responses to infection in the future health scenario. Therefore, probiotics have emerged as an alternative to antibiotics. This study aimed to isolate and identify a Lactobacillus casei from healthy canine skin and investigate its antimicrobial effect on isolates of Staphylococcus pseudintermedius originating from dogs with pyoderma. L. casei was isolated from skin samples collected with a sterile cotton swab from the inner pinnae of healthy dogs. It was then cultured, identified using matrix-assisted laser desorption ionisation time-of-flight mass spectrometry, and tested against 30 different clinical isolates and one American Type Culture Collection strain of S. pseudintermedius using the spot-on-the-lawn technique. Its safety was assessed through a modified Kirby-Bauer disc diffusion susceptibility test. L. casei inhibited the growth of all isolates of S. pseudintermedius. The mean value of the inhibition halo of all isolates was 11.3 mm. A significant positive correlation (Pearson's linear correlation = 0.444; p = 0.014) was noted between the inhibitory halos formed by L. casei on the S. pseudintermedius isolates and the halos produced by the tested antimicrobial discs on the same isolates. The L. casei strain demonstrated sensitivity to all tested antimicrobials. The study indicates that using commensal bacteria from canine skin, specifically L. casei, to control bacterial infections caused by S. pseudintermedius can be a promising complementary or alternative therapy to antibiotics relevant to animal and human health.

Differential Antimicrobial Potential of Ajuga integrifolia Buch. Ham. Ex D.Don Based on Extraction Solvents

The current study aimed to evaluate the effect of extraction solvents on the anti-bacterial and anti-fungal efficacy of the stem and roots of Ajuga integrifolia Buch. Ham. ex D. Extracts were prepared in different solvents and tested against fungi and bacteria species including, Agrobacterium tumefaciens, Xanthomonos oryzae, Citrobacter freundi, Alternaria alternata, A. solani and Aspergillus niger. Antibacterial efficacy of the Ajuga integrifolia was carried out by disc diffusion susceptibility method and antifungal efficacy by well diffusion susceptibility method. Methanol stem extract revealed efficacy against C. freundi by producing a 63% zone of inhibition at 3000µg/disc while methanol roots extract produced 77% ZI against A. tumifaciens. Methanol root and stem extracts produced an equal zone of inhibition (97%) at 1000 µg/ml concentration against A. alternata and A. solani. The results of the study clearly stated that the polarity of the solvents used in the extraction procedure affects the bioactivities of the extracts.

Interactions among Zinc, Iron, and Paraquat in the Physiological and Toxicological Responses of the Egyptian Cotton Leafworm Spodoptera littoralis.

Agricultural pollutants co-interact and affect the vital functions, stress tolerance, resistance, immunity, and survival of insect pests. These metal-herbicide interactions have inevitable but remarkable effects on insects, which remain poorly understood. Here, we examined the effects of the interactions among zinc (Zn), iron (Fe), and paraquat (PQ) at a sublethal dose on the physiological response of the Egyptian cotton leafworm Spodoptera littoralis. Co-exposure to Zn and Fe improved leafworm survival (100% at 10-20 mg, 85% at 40 mg) compared to separate exposures. Low Zn/Fe/PQ toxicity likely stemmed from metal complexes having efficient chelating activity, enhancing resilience. Low exposure to Zn, Fe, and Zn/Fe increased food intake and larval weight and affected frass production. Interestingly, the combined application of Zn/Fe/PQ increased larval and pupal weight in surviving individuals. Zn/Fe was found to be crucial in the ecdysis of larvae into pupae, resulting in reduced larval mortality and a prolonged pupal ecdysis duration (% days). Providing important information regarding physiological responses and pest management, this study demonstrated the realistic conditions caused by the interactions of biological trace elements, such as Zn and Fe, with PQ. A disc diffusion susceptibility test in hemolymph bacteria revealed differences among Zn, Zn/Fe, and Zn/Fe/PQ, suggesting that their interaction might play an immunomodulatory role in S. littoralis.

Evaluation of anti-acne activity of human whole saliva against acne vulgaris: An invitro study.

Acne vulgaris (AV) is a multifactorial inflammatory skin disorder, affecting 9.45% of the world's population. AV can be painful, discomforting, and disfiguring due to scarring, leading to physiological distress, and economic burden. AV pathogenies can be due to various factors, key ones include follicular plugging, colonization by the microorganism, endocrinological factors, and inflammation. Gram-positive bacteria Cutibacterium acnes and Staphylococcus epidermidis are the most common pathogens isolated from patients with AV. The present study aimed to investigate the anti-acne activity of whole human saliva against bacteria that cause AV. The saliva sample from four different individuals was collected at three different intervals. These samples were used to perform antimicrobial susceptibility test (AST) against the pathogens. Kirby-Bauer disk diffusion susceptibility test, and Broth dilution method using Resazurin were performed. The human saliva was effective in inhibiting Cutibacterium acnes and Staphylococcus epidermidis those causing AV. The Minimum inhibitory activity and disc diffusion assay depicted potency of saliva. The pH of the saliva samples was found to be more acidic in the morning samples when compared with the evening samples. The afternoon sample was found to be more effective when compared with the other two intervals. Saliva shows effective anti-acne activity by inhibiting the growth and proliferation of acne-causing bacteria.

CRISPR/Cas9-Mediated Genome Editing of T4 Bacteriophage for High-Throughput Antimicrobial Susceptibility Testing.

The accurate and effective determination of antimicrobial resistance is essential to limiting the spread of infectious diseases and ensuring human health. Herein, a simple, accurate, and high-throughput phage-based colorimetric sensing strategy was developed for antimicrobial susceptibility testing (AST). Taking advantage of the CRISPR/Cas9 system, the genome of the T4 phage was modularly engineered to carry lacZ-α (lacZa), a marker gene encoding the α-fragment of β-galactosidase (β-gal). T4lacZa phages were identified by blue-white selection and then used for a biosensing application. In this strategy, the bacterial solution is exposed to the T4lacZa phage, causing target bacteria to overexpress β-gal. Upon the addition of a colorimetric substrate, the β-gal initiates an enzymatic reaction, resulting in a solution color change from yellow to red. This sensing strategy offers a visual way to monitor bacterial growth in the presence of antibiotics, enabling the determination of bacterial antimicrobial susceptibility. As a proof of concept, our developed sensing strategy was successfully applied to identify 9 different multidrug-resistant Escherichia coli (E. coli) in urine samples with 100% specificity. Compared with conventional disk diffusion susceptibility tests, the engineered phage-based sensing strategy can shorten the detection time by at least half without losing detection sensitivity, providing an alternative high-throughput method for AST in clinical diagnosis.

The context of blaOXA-23 gene in Iraqi carbapenem-resistant Acinetobacter baumannii isolates belonging to global clone 1 and global clone 2.

Of the genes conferring resistance to carbapenems in Acinetobacter baumannii, the blaOXA-23 gene is the most widely found across the world. The gene carrying blaOXA-23 transposons in A. baumannii isolates of global clones GC1 and GC2 is found worldwide. Here, we examined whether transposons play a role in the dissemination of the blaOXA-23 in globally distributed clones, GC1 and GC2 A. baumannii isolates from Iraq. The 119 non-repetitive A. baumannii isolates including 94 recovered from clinical specimens and 25 isolates from hospital environment between September 2021 and April 2022 from different medical centers located at various regions in Baghdad, Iraq. The global clones (GC) and the genes encoding carbapenem resistance, including blaOXA-23, blaOXA-24, and blaOXA-58 were identified using multiplex PCR assays. Antibiotic susceptibility testing was performed by the Kirby-Bauer disk diffusion susceptibility method. The transposons carrying blaOXA-23 were examined using PCR mapping. In cases when carbapenem susceptible A. baumannii isolates were found, they were subjected to E test, full length sequencing of blaOXA-Ab (blaOXA-51-like) and Institut Pasteur multi-locus sequence typing scheme. All but two isolates (92 clinical and 25 environmental) were identified carbapenem-resistant A. baumannii (CRAB). Of 117 CRAB isolates, 20 belong to GC1, 19 contained blaOXA-23; of them, 17 isolates harbored the blaOXA-23 located on Tn2006. Among the 46 CRAB belonging to GC2, 39 contained blaOXA-23; of them, 34 carried the blaOXA-23 located on Tn2006. The remaining GC1 and GC2 isolates, one GC1 as well as one GC2 isolate, were susceptible to imipenem, doripenem, and meropenem and considered carbapenem-susceptible A. baumannii (CSAB). Full-length sequencing of the blaOXA-Ab and MLST for the two CSAB isolates belonging to GC1 and GC2 confirmed that the GC1 isolate belongs to ST 623 and contained an allele that encodes an blaOXA-69 variant of the blaOXA-Ab while the GC2 belong to ST2 and carried an blaOXA-66 variant. This study provides evidence for the dissemination of blaOXA-23 on the Tn2006 in CRAB isolates in Baghdad, Iraq. It appears that this transposon is widespread in GC1 and 2 isolates as in the other parts of the world. Interestingly, one GC1 and one GC2 isolate from Iraq were found to be susceptible to carbapenem while the isolates belonging to GC1 and GC2 have so far rarely been found to be susceptible to carbapenem globally.

Determination of Biological Activity of Hylocereus polyrhizus Methanol Extracts: Antimicrobial Activity, Probiotic-Promoting Effect, Photoprotective Activity

In our study, the biological activity of Hylocereus polyrhizus obtained from Türkiye was determined. Firstly, antimicrobial activity of methanol extracts obtained from H. polyrhizus against test microorganisms was determined by disc diffusion susceptibility assay, minimum inhibition concentration (MIC) and minimum fungicidal or bactericidal concentration (MFC or MBC) tests. Then, viable cell counting against Limosilactobacillus fermentum MA-7 using the macro-dilution method was used to determine the probiotic-promoting effect of the fruit extracts. Finally, the photo-protective activity of the extracts and extract-cream mixtures was obtained spectrophotometrically. The inhibition zone diameter of the peel extract against the test microorganisms is in the range of 9.60-12.37 mm and the fruit extract is in the range of 7.85-12.00 mm. MBC values ranged from 40 µg/µl to 80 µg/µl in peel extract and between 10 µg/µl and >80 µg/µl in the fruit extract. The inhibition zone diameters of the extracts against probiotics were determined as 6.10 -10.25 mm. As a result of the viable cell count, the viability rate of L. fermentum MA-7 increased as the fruit methanol extract concentration and time increased. The photoprotective activities of the peel and fruit extracts were determined as 13.17 and 12.26. It was determined that the extracts increased sun protection factor (SPF) value of the cream. The results indicated that H. polyrhizus extracts may have potential for use in the nutraceutical products, cosmetic and pharmaceutical industries.

Frequency of Carbapenem Resistance in UTI Patients in a Tertiary Level Hospital

Background: Urinary tract infections (UTIs) remain the common infections diagnosed in outpatients as well as hospitalized patients. Current knowledge on antimicrobial susceptibility pattern is essential for appropriate therapy. Extended-Spectrum Beta-Lactamase (ESBL) producing bacteria may not be detected by routine disk diffusion susceptibility test, leading to inappropriate use of antibiotics and treatment failure. The aim of this study was to determine the distribution and antibiotic susceptibility patterns of bacterial strains isolated from patients with community acquired urinary tract infections (UTIs) at Comilla Medical College Hospital, Comilla as well as identification of ESBL producers in the population of different uropathogens. Objectives: To obseve the frequency of carbapenem resistance in UTI patients in a tertiary level hospital. Methods: This cross sectional observational study was done on inpatients and outpatients department of Comilla Medical College Hospital, Comilla in 6 months’ period. Formal ethical approval was taken before commencement of the study. Adult patients presenting with features of UTI were approached and finally selected in accordance to selection criteria. Convenience sampling technique was applied to enroll the total 100 study population. Following describing the purpose, methods and benefits of study written consent was taken from each patient. All patients were subjected to detail history, clinical examination and relevant investigation. Value of clinical investigations were noted on questionnaire. Following data collection, all were verified and prepared for data entry. Final analysis was done by using SPSS version 19. Results: Out of 100 patients attending in Comilla Medical College Hospital with symptoms suggestive of UTI, 31% had culture positive. Our study showed a high prevalence of UTI in females (61%) than in males (39%). Most common symptom was urgency (88%) followed by abdominal pain (77%), dysuria (67%) and ........

Comparative Evaluation of the Antibiotic Resistance Profile of Staphylococcus aureus Isolated From Breeders and Livestock.

Animals are a potential source of Methicillin Resistant Staphylococcus aureus. This study evaluated the antibiotics susceptibility pattern of S. aureus isolates from breeders and livestock. S. aureus strains were isolated from 180 livestock and 48 livestock farmers and identified using standard methods. Antibiotic susceptibility profiles and MRSA status were determined via disk diffusion susceptibility method. Among farm workers, 37.5% were colonized by S. aureus, with pig farm workers exhibiting the highest prevalence (56.2%), cattle herders (37.5%), and goat farm workers (18.7%). MRSA carriage among livestock isolates was 41.3%, while, six isolates from the poultry farm worker were MRSA, representing a carriage of 33.3%. Drug susceptibility profiles revealed differential patterns between isolates from breeders and animals. Gentamicin and levofloxacin demonstrated higher efficacy against farm worker isolates compared to animal isolates. Resistance to cefuroxime was higher among animal isolates (84.1%) as against the 66.7% for the breeders. The identification of multidrug-resistant S. aureus strains underscores the risk posed to humans in contact with animals. These findings stress the importance of monitoring and managing MRSA transmission between animals and humans.

Exploring bacterial profiles and antibiotic susceptibility patterns in urinary tract infection cases at Idlib university hospital, Syria

The main objective of this study was to identify, analyze, and evaluate the bacteriological profile and antimicrobial susceptibility patterns of symptomatic urinary tract infections (UTIs) among patients at Idlib University Hospital in Northwest Syria. By isolating and characterizing the uropathogens, the study aimed to gain insights into their current antimicrobial susceptibilities. This information is crucial in order to combat the increasing antibiotic resistance and provide effective treatment options for UTIs, which are prevalent both in the community and hospital settings.This observational research took place at Idlib University Hospital in Northwest Syria spanning from June 2022 to December 2023. Our study involved 320 patients exhibiting symptoms of UTI (68.4% females and 31.6% males). Urine samples were cultured to identify the microorganisms responsible for UTI. Biochemical tests were employed to identify the isolated bacteria, while the antimicrobial susceptibility was determined through disk diffusion susceptibility testing. Our study found to be the leading cause of UTIs, accounting for 58.4% of cases, followed by spp. Gram-negative bacteria comprised 85% of isolated strains. The 13–65 age group showed the highest UTI susceptibility (41.3%). High resistance was observed to ampicillin/sulbactam, cefotaxime, ceftriaxone, and co-trimoxazole. Conversely, minimal resistance was noted against Meropenem, Imipenem, Gentamicin, and Levofloxacin.This research highlights the prevalence of antibiotic-resistant infections within the hospital under study. Hence, there is an imperative to enhance the efficiency of comprehensive infection control initiatives to effectively handle and regulate hospital-acquired infections caused by highly resistant microorganisms.

Antibacterial Activity of Pineapple (Ananas comosus) Fruit Peel Extract Against Escherichia coli

Escherichia coli is generally considered a harmless bacterium, but numerous strains are well-known for causing diseases globally and frequently exhibit antibiotic resistance. Therefore, it's crucial to discover new natural products to combat these bacteria. Meanwhile, a significant amount of pineapple (Ananas comosus) peel ends up as waste. This study aims to examine the antibacterial activity of pineapple (Ananas comosus) fruit peel extract against E. coli. The preparation of pineapple (Ananas comosus) peel extract involves grinding, maceration with 96% ethanol, and evaporation. The phytochemical test was conducted to assess the presence of active compounds. Flavonoids were identified using Shinoda's test, tannins with Ferric Chloride, and saponins by detecting foaming development. Antibiotic analysis was carried out following the Kirby-Bauer Disk Diffusion Susceptibility Test Protocol. Disks soaked in Ananas comosus peel extract at concentrations of 25%, 50%, 75%, and 100% were placed on Mueller-Hinton (MH) agar inoculated with an E. coli suspension. One-way ANOVA was employed to analyze differences between treatments. The phytochemical test results revealed the presence of flavonoids, tannins, and saponins in pineapple peel extract. The highest inhibition zone, measuring 2.231 mm, was observed with 100% Ananas comosus peel extract. Statistical analysis confirmed significant differences between the groups with a significance value of 0.000 (p<0.05). This suggests that pineapple peel extract could be useful in removing E. coli, rather than being discarded as waste. Further research is needed to gain a better understanding of the antibacterial mechanism.

Gram Positive Cocci Associated Urinary Tract Infections, their Prevalence and Antibiotic Susceptibility Patterns

Background: Urinary tract infections (UTIs) are the third most common type of infection in humans globally. Gram-positive bacteria are said to be responsible for ten percent of urinary tract (UTI) infections. The study's goal was to profile gram-positive cocci-associated UTIs and their antibiogram, as they were observed at LASUTH. Methods: This was a retrospective assessment of the Medical Microbiology Laboratory records of the LASUTH to review the in vitro antibiotic susceptibility patterns of gram-positive urinary bacterial isolates between April 2020 and March 2021. The bacteria were isolated and identified from routine urine samples using standard bacteriological methods and the API. In vitro antibiotic susceptibility test (AST) was routinely performed by the modified Kirby-Bauer disk diffusion test and susceptibility breakpoints were determined using the Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: 2,253 urine samples were processed in the medical microbiology laboratory over the one year and 662 (29.4%) samples yielded Positive cultures. Of the 662 isolates, 494 (74.6%) were gram-negative bacteria. 164 (24.8%) were gram-positive cocci while 4 (0.6%) were gram positive rod. Among the gram-positive cocci’s isolated Enterococcus faecalis had the highest frequency 58 (35.4%). Aminoglycosides (Gentamycin and Amikacin) and Linezolid antibiotics were found to be the most effective drugs against gram-positive cocci bacteria except Enterococcus spp. For empirical treatment of Enterococcus spp in our facility Fosfomycin and Tigecycline are the best options, while for Streptococcus agalactiae associated UTI, Amikacin, Cefuroxime, Linezolid, and levofloxacin can be used for empirical treatment. Conclusion: The prevalence rate of gram-positive cocci associated UTI in this study was 7.3% (164/2253). The emergence of drug resistance in these pathogens to commonly used antibiotics is a thing of concern. Therefore, efficient antimicrobial stewardship programmes must be in place.

In vitro and in vivo burn healing study of standardized propolis: Unveiling its antibacterial, antioxidant and anti-inflammatory actions in relation to its phytochemical profiling.

Natural propolis has been used since decades owing to its broad-spectrum activities. Burn injuries are a global health problem with negative impacts on communities. Bacterial infections usually accompany burns, which demand implementation of antibiotics. Antibiotics abuse led to emergence of microbial drug resistance resulting in poor treatment outcomes. In such instances, the promising alternative would be natural antimicrobials such as propolis. Full chemical profiling of propolis and evaluation of in vitro antibacterial, antioxidant and anti-inflammatory activities as well as in vivo burn healing properties. Chemical profiling of propolis was performed using Liquid chromatography (UHPLC/MS-PDA and HPLC-PDA). In vitro assessment was done using Disc Diffusion susceptibility test against Staphylococcus aureus and infected burn wound mice model was used for in vivo assessment. In vitro antioxidant properties of propolis were assessed using DPPH, ABTS and FRAP techniques. The anti-inflammatory effect of propolis was assessed against lipopolysaccharide/interferon-gamma mediated inflammation. UHPLC/MS-PDA results revealed identification of 71 phytochemicals, mainly flavonoids. Upon flavonoids quantification (HPLC-PDA), Pinocembrin, chrysin and galangin recorded high content 21.58±0.84, 22.73±0.68 and 14.26±0.70 mg/g hydroalcoholic propolis extract, respectively. Propolis showed concentration dependent antibacterial activity in vitro and in vivo burn healing via wound diameter reduction and histopathological analysis without signs of skin irritation in rabbits nor sensitization in guinea pigs. Propolis showed promising antioxidant IC50 values 46.52±1.25 and 11.74±0.26 μg/mL whereas FRAP result was 445.29±29.9 μM TE/mg. Anti-inflammatory experiment results showed significant increase of Toll-like receptor 4 (TLR4), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) mRNA levels. Nitric oxide and iNOS were markedly increased in Griess assay and western blot respectively. However, upon testing propolis against LPS/IFN-γ-mediated inflammation, TLR4, IL-6 and TNF-α expression were downregulated at transcriptional and post-transcriptional levels. Propolis proved to be a promising natural burn healing agent through its antibacterial, antioxidant and anti-inflammatory activities.

Antimicrobial and antioxidant activities of lignin by-product from sugarcane leaf conversion to levulinic acid and hydrochar

To enhance the sustainability of lignocellulosic biomass utilization process, a significant attention is given to a high-value lignin byproduct of this process. Herein, antimicrobial, antioxidant, and physicochemical properties of lignin in black liquor extracted from sugarcane leaf (SCL) for levulinic acid (LA) and hydrochar production were investigated. The lignin was extracted from SCL through an alkaline pretreatment process using 5–25 wt% of either NaOH or KOH at 120–160 °C. Disk diffusion susceptibility tests, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) revealed that the SCL lignin is effective against Gram-positive bacteria (S. aureus) rather than Gram-negative bacteria (E. coli and S. typhimurium). Different alkaline reagents marginally affected the antimicrobial and antioxidant activities of the lignin. Py-GC/MS analysis results determined that the SCL lignin contained mainly p-hydroxyphenyl (H) and guaiacyl (G) with a small amount of syringyl (S) lignin. Furthermore, the structural alterations and linkages of SCL lignin during alkaline pretreatment were examined using 2D-HSQC NMR, providing valuable insights into the transformation processes. The conversion of delignified SCL to LA through a catalytic hydrothermal process using various acid catalysts indicated that the alkaline pretreatment could enhance LA yield with a maximum yield of 33.4 wt%. Additionally, fuel property characterization of the hydrochar co-product from LA production determined that the hydrochar can be used as a coal substitute.

Comparison of BD Phoenix and disk diffusion to broth microdilution for determining cefepime susceptibility among carbapenem-resistant Enterobacterales.

There are increasing reports of carbapenem-resistant Enterobacterales (CRE) that test as cefepime-susceptible (S) or susceptible-dose dependent (SDD). However, there are no data to compare the cefepime testing performance of BD Phoenix automated susceptibility system (BD Phoenix) and disk diffusion (DD) relative to reference broth microdilution (BMD) against carbapenemase-producing (CPblaKPC-CRE) and non-producing (non-CP CRE) isolates. Cefepime susceptibility results were interpreted according to CLSI M100Ed32. Essential agreement (EA), categorical agreement (CA), minor errors (miEs), major errors (MEs), and very major errors (VMEs) were calculated for BD Phoenix (NMIC-306 Gram-negative panel) and DD relative to BMD. Correlates were also analyzed by the error rate-bounded method. EA and CA for CPblaKPC-CRE isolates (n = 64) were <90% with BD Phoenix while among non-CP CRE isolates (n = 58), EA and CA were 96.6%, and 79.3%, respectively. CA was <90% with DD for both cohorts. No ME or VME was observed for either isolate cohort; however, miEs were >10% for CPblaKPC-CRE and non-CP CRE with BD Phoenix and DD tests. For error rate-bounded method, miEs were <40% for IHigh + 1 to ILow - 1 ranges for CPblaKPC-CRE and non-CP CRE with BD Phoenix. Regarding disk diffusion, miEs were unacceptable for all MIC ranges among CPblaKPC-CRE. For non-CP CRE isolates, only IHigh + 1 to ILow - 1 range was acceptable at 37.2%. Using this challenge set of genotypic-phenotypic discordant CRE, the BD Phoenix MICs and DD susceptibility results trended higher (toward SDD and resistant phenotypes) relative to reference BMD results yielding lower CA. These results were more prominent among CPblaKPC-CRE than non-CP CRE.

Antibiotic resistance of enteropathogenic bacteria in a teaching hospital in North Khuzestan during a three-year period.

Gastrointestinal infections affect many people annually. The most common bacterial agents involved in these infections are enteropathogenic bacteria and in the continuation of using broad-spectrum antibiotics, Clostridium difficile-associated diarrhea is involved, especially in hospitalized patients. The aim of the present study was to investigate the pattern of antibiotic resistance among enteropathogenic bacteria. In this cross-sectional study, 163 samples of patients with diarrhea in Dezful Ganjavian Hospital were examined. The samples were cultured in MacConkey, Hektoen enteric agar and GN broth, and cycloserine cefoxitin fructose agar media and incubated under standard conditions. In order to identify enteropathogenic bacteria, biochemical tests and serological confirmatory tests were used. Antibiotic resistance pattern of the isolates was investigated by Kirby-Bauer disk diffusion susceptibility test. The frequency of pathogenic bacteria includes 41.1% of Shigella flexneri, followed by 41.1% of S. sonnei, 6.7% of Enteropathogenic E. coli, 5.5% of Salmonella enterica Serogroup B, and 5.5% of Shigella dysenteriae. The results revealed a total of 46 patients with orders regarding C. difficile culture, no C. difficile was isolated from the samples. The studied isolates showed the highest resistance to trimethoprim-sulfamethoxazole, and ceftriaxone (88.3%), and the most effective antibiotic in the treatment of patients was ciprofloxacin with 86% sensitivity. Susceptibility to antibiotics was different among the isolates, which shows that the early identification of the infection agent and the selection of the correct antibiotic treatment are effective in improving the gastrointestinal infection and preventing the spread of the infection.

Cobalt, Copper and Magnesium Doped Nickel Zinc Nanoferrites by Solution-Combustion Method: Structural, Antibacterial and Antifungal Properties

The nickel zinc nanoferrites with configurationNi0.45Zn0.55–xMxFe2O4were achieved where x = 0.0, 0.1, 0.2 and 0.3 and M = Cobalt, Copper, Magnesiumusing solution-combustion method by availing sucrose as a fuel. The procured nanoferrites were investigated forstructural properties using TEM, antibacterial and antifungal propertiesby Kirby-Bauer Disk Diffusion Susceptibility Test also calledas Agar diffusion method. The synthesized nanoferrites were tested for their antibacterial activities against Gram negative (Escherichiacoli) and Gram positive (Bacillus cerus) bacterial strains. Also, investigation was evaluated for their antifungal activity against Aspergillus niger. Against Bacillus cerus, sample Ni0.45 Zn0.45Cu0.1Fe2O4 showed maximum antibacterial activity. The maximum antifungal activity was observed for Ni0.45 Zn0.35Co0.2Fe2O4.