Antimicrobial Profiles Research Articles

1692. Ceftibuten-Xeruborbactam: In vitro Potency against Enterobacterales in Comparison with Other Oral Beta-lactams (BL) and Beta-lactamase Inhibitor (BLI) Combinations

Abstract Background The broad spectrum BLI xeruborbactam (XER, formerly, QPX7728) can be delivered IV or orally as the isobutyryloxymethyl prodrug. The prodrug form is in clinical development in combination with ceftibuten (BUT) for oral treatment of resistant gram-negative infections. The objective of this study was to compare the in vitro potency of BUT-XER to that of other investigational oral BL/BLI combinations and tebipenem (TBP) in blinded head-to-head testing against extended beta-lactamase (ESBL) producing and carbapenem-resistant Enterobacterales (CRE). Methods A total of 980 Enterobacterales including 515 ESBL and 460 CRE, including 195 KPC-, 97 OXA-48-like- and 168 metallo beta-lactamase (MBL) producers, were susceptibility tested by reference broth microdilution against BUT-XER (at fixed 4 mg/L) and comparator BLs or BL/BLI combinations (tested at their recommended BLI concentrations). MIC testing was conducted blinded to drug identity using CLSI reference microdilution methods and controlled using approved quality control bacterial strains and ranges. Results BLI inhibitor combinations and TBP had excellent potency against ESBL isolates with MIC90 in the ≤ 0.03-0.06 mg/L range for BUT-avibactam (AVI) and BUT-XER and in 0.125-0.25 mg/L range for TBP, BUT-VNTX-6236 (VNRX) and cefpodoxime (CPD)-ETX1317 (ETX) (Table). Against KPC and OXA-48-producers, BUT-XER and BUT-AVI (MIC90 0.25-0.5 mg/L) were 4-fold more potent than BUT-VNRX and CPD-ETX (MIC90 of 1-2 mg/L); TBP was not active against these strains. BUT-XER and CPD-ETX were the most potent agents against MBL-producing strains; however, anti-MBL activity of CPD-ETX was due to intrinsic antibacterial activity of ETX. TPB, BUT-AVI and BUT-VNTX did not have any relevant activity against MBL-producing strains. Conclusion BUT-XER had the broadest antimicrobial profile, with activity against ESBL and all carbapenemase producing isolates. Its potency against ESBL-producing isolates was comparable to the carbapenem TBP. Its in vitro potency and spectrum combined with the potential of once-daily administration based on PK studies warrants further clinical development. Disclosures Mariana Castanheira, PhD, AbbVie: Grant/Research Support|Cidara: Grant/Research Support|GSK: Grant/Research Support|Melinta: Grant/Research Support|Pfizer: Grant/Research Support|Shionogi: Grant/Research Support Jill Lindley, BS, AbbVie: Grant/Research Support.

Evaluation of antimicrobial susceptibility and genetic profiles (ERIC-PCR) of Enterococcus species, isolated from chicken viscera

The genus Enterococcus can be found in water, soil, and food, and above all, they are part of the animal (including human) intestinal microbiota. Food prevalence is mainly due to their resistance to adverse environmental conditions. Seventy-three isolates from chicken viscera were confirmed to belong to the Enterococcus genus by biochemical tests and carbohydrate fermentation. Phenotypic characterization of the species indicates that E. casseliflavus was the predominant specie. Antimicrobial resistance to amikacin (42 %), kanamycin (38 %), streptomycin (55 %), and erythromycin (33 %) in the isolates was notorious. The analysis obtained from ERIC-PCR profiles shows a high genetic variability among the isolates. In addition, a relationship between the antimicrobial and ERIC-PCR profiles was observed among isolates. These results indicate the presence of multi-resistant Enterococcus in commercial chicken viscera with high genetic variability, which could be a potential nosocomial bacterium or transfer this resistance to another pathogenic species causing human diseases.

Epidemiology, Evolution of Antimicrobial Profile and Genomic Fingerprints of Pseudomonas aeruginosa before and during COVID-19: Transition from Resistance to Susceptibility.

The purpose of the study was to describe the epidemiological implication of Pseudomonas aeruginosa between 2017-2022 in a tertiary hospital from Romania, including the molecular fingerprinting of similar phenotypic strains (multidrug-resistant isolates), which would have an important health impact. The study also describes the resistance profile of P. aeruginosa before and during COVID-19, which might bring new information regarding the management of antibiotic treatments. Information regarding wards, specimen types, species, and antibiotic resistance profile of 1994 strains of Pseudomonas spp. Isolated over a period of 6 years in Mures Clinical County Hospital, Romania, was collected from the WHONET database. From 50 multidrug-resistant isolates, molecular fingerprinting was performed by Enterobacterial Repetitive Intergenic Consensus Polymerase Chain Reaction (ERIC-PCR) to prove the potential clonal distribution. A number of 1994 Pseudomonas spp. were isolated between 2017-2022, from which P. aeruginosa was the most frequent species, 97.39% (n = 1942). P. aeruginosa was most frequently isolated in 2017 (n = 538), with the dermatology department as the main source, mainly from pus secretion. A drop in the harvesting rate was noted in 2020 due to COVID-19 restrictions. Regarding the resistance profile, there are a few modifications. The susceptibility of P. aeruginosa to carbapenems, piperacillin-tazobactam, and amikacin suffered alterations before and during COVID-19. The molecular fingerprinting showed three P. aeruginosa clusters, including strains with 80-99% similarity.

Evaluation of biofertilization on antimicrobial activity and phytochemical profile of Moringa olifera plant

Evaluation of biofertilization on antimicrobial activity and phytochemical profile of Moringa olifera plant

Identification, 16S rRNA-based characterization, and antimicrobial profile of Gallibacterium isolates from broiler and layer chickens.

Gallibacterium spp., particularly G. anatis, have received much attention as poultry pathogens in recent years. We report here the presence and antimicrobial resistance profile of 69 Gallibacterium isolates obtained from 2,204 diagnostic submissions of broiler and layer chickens in 2019-2021. Gallibacterium-positive chickens had lesions primarily in the respiratory tract, reproductive tract, and related serosal surfaces. Gallibacterium spp. were initially identified based on their typical cultural characteristics on blood agar. The isolates were confirmed by a genus-specific PCR spanning 16S-23S rRNA and MALDI-TOF mass spectrometry. Phylogenetic analysis based on 16S rRNA gene sequence revealed distinct clades. Of the 69 isolates, 68 clustered with the reference strains of G. anatis and 1 with Gallibacterium genomospecies 1 and 2. Antimicrobial susceptibility testing of 58 of the 69 isolates by a MIC method showed variable responses to antimicrobials. The isolates were all susceptible to enrofloxacin, ceftiofur, florfenicol, and gentamicin. There was a high level of susceptibility to trimethoprim-sulfamethoxazole (98.0%), streptomycin (98.0%), amoxicillin (84.0%), sulfadimethoxine (71.0%), and neomycin (71.0%). All of the isolates were resistant to tylosin. There was resistance to penicillin (98.0%), erythromycin (95.0%), clindamycin (94.0%), novobiocin (90.0%), tetracycline (88.0%), oxytetracycline (76.0%), and sulfathiazole (53.0%). A high rate of intermediate susceptibility was observed for spectinomycin (67.0%) and sulfathiazole (40.0%). Our findings indicate a potential role of G. anatis as an important poultry pathogen and cause of subsequent disease, alone or in combination with other pathogens. Continuous monitoring and an antimicrobial susceptibility assay are recommended for effective treatment and disease control.

Facile One Pot Synthesis of Acridinediones Using Caffeine Hydrogen Sulfate Catalyst and Their Antimicrobial Evaluation

A facile approach for the synthesis of bioactive acridinedione analogs using dimedone, aryl aldehydes, and ammonium acetate was developed using caffeine hydrogen sulfate catalyst in ethanol and water (2:1) solvent mixture at room temperature. The significant advantages of this procedure are efficient and simple method, ambient conditions, short reaction time (5–30 min), simple workup, easily recoverable catalyst, broad substrate scope and good yields (45–80%). Being water soluble, the catalyst was easily recovered by water and reused up to 4 runs. Moreover, the antimicrobial profile of synthesized derivatives was performed against different bacterial and fungal strains using broth microdilution method. Most of the synthesized derivatives exhibited significant activity against bacterial and fungal strains compared to standard. Compounds 4e (31.25 µg/mL and 31.25 µg/mL) and 4g (31.25 µg/mL and 62.5 µg/mL) were found the most active against E. coli. and S. aureus respectively with good MIC values. Compound 4f and 4j displayed the highest antifungal activity against A. niger with 31.25 µg/mL MIC value.

The synergistic effect of capsicum aqueous extract (Capsicum annuum) and chitosan against multidrug-resistant bacteria

ObjectivesThis study investigated the effects of chitosan, capsicum and chitosan and capsicum combined (Capsicum annuum) on Gram-positive pathogenic bacteria, such as Staphylococcus aureus, and Gram-negative bacteria, such as Salmonella typhimurium and Pseudomonas aeruginosa. MethodsThe obtained extracts were categorised as chitosan, capsicum and chitosan and capsicum combined. The antimicrobial action of the extracts was determined by the inhibition zone compared to the control. Antimicrobial bioassays using S. typhimurium, P. aeruginosa and S. aureus were performed on the extracts. ResultsThe antimicrobial profiles showed that the chitosan and capsicum combined possessed antimicrobial effects. This is mostly attributed to the high concentration of components that possess antibacterial action. The growth of bacterial pathogens was inhibited by all samples of capsicum with chitosan, but the largest inhibition zone was against S. typhimurium (18 mm) with a capsicum and chitosan concentration of 10 mg/ml. ConclusionThe combination of chitosan and capsicum can be effective against pathogenic bacteria. This is an innovative approach to enhancing these extracts’ antibacterial activity. Further investigation is required to explore further aspects of these extracts’ antimicrobial activity against pathogenic bacteria. The observed results showed that chitosan and capsicum were more active against S. aureus.

Assessment on the Awareness of Antimicrobial Drug Resistance on Human Health and Animal Health Professionals and Antimicrobial Profile of Staphylococcus aureus from Kality Clinic in Addis Ababa, Ethiopia

A cross-sectional study with purposive sampling was conducted from November 2021 to March 2022 to investigate the antimicrobial susceptibility patterns of Staphylococcus aureus. A questionnaire survey was also undertaken to assess the awareness of human and animal health professionals from St.Paul Hospital and Addis Ababa University- Aklilu Lemma Pathobiology Institute / AAU-ALIPB/ on antimicrobial drug resistance. Out of the 40 participants 20 of them were physicians and the remaining 20 were veterinarians. Among the interviewed 20 veterinary professionals 80% of them were well aware of antimicrobial drug resistance and its impact on animal and public health. Parallel to that all veterinarians involved in this questionnaire survey or 100% of them had previous knowledge on one health approach and its role in solving the problem of anti-microbial drug resistance. Compared to the veterinarians, about 39.3% of physicians had poor awareness and knowledge on AMDR. Besides this only 40% of the physician know about one health approach and its role in fighting against AMDR. A statistically significant (P<0.05) relation was observed between the professionals and their knowledge. A total of Forty wounds, and nasal and vaginal swab samples from bovine, ovine, caprine and equine species were collected for Staphylococcus aureus isolation and antimicrobial susceptibility test. The samples collected from Kality veterinary clinic were examined using standard microbiological techniques including culture, colony characterization, primary and secondary biochemical tests as well as species-level identification of S.aureus done by Matrix-Assisted Laser Desorption/Ionization (MALDI) Bio typer. Among the 40 samples, only 3 S.aureus is confirmed. Out of the tested 3 isolates, 100% of them were highly resistant to Penicillin G, and 100% of isolates were equally susceptible to all list of drugs used. Staphylococcus aureus completely develops resistance to penicillin G which mean this antibiotic doesn’t have any relevant importance in treating clinical cases that are caused by pathogenic Staphylococcus aureus species in both human and animal.

Differential plasticity and fate of brain-resident and recruited macrophages during the onset and resolution of neuroinflammation.

Microglia and border-associated macrophages (BAMs) are brain-resident self-renewing cells. Here, we examined the fate of microglia, BAMs, and recruited macrophages upon neuroinflammation and through resolution. Upon infection, Trypanosoma brucei parasites invaded the brain via its border regions, triggering brain barrier disruption and monocyte infiltration. Fate mapping combined with single-cell sequencing revealed microglia accumulation around the ventricles and expansion of epiplexus cells. Depletion experiments using genetic targeting revealed that resident macrophages promoted initial parasite defense and subsequently facilitated monocyte infiltration across brain barriers. These recruited monocyte-derived macrophages outnumbered resident macrophages and exhibited more transcriptional plasticity, adopting antimicrobial gene expression profiles. Recruited macrophages were rapidly removed upon disease resolution, leaving no engrafted monocyte-derived cells in the parenchyma, while resident macrophages progressively reverted toward a homeostatic state. Long-term transcriptional alterations were limited for microglia but more pronounced in BAMs. Thus, brain-resident and recruited macrophages exhibit diverging responses and dynamics during infection and resolution.

NDM-1 and OXA-48-Like Carbapenemases (OXA-48, OXA-181 and OXA-252) Co-Producing Shewanella xiamenensis from Hospital Wastewater, China.

Shewanella genus, as an important carrier of resistance genes, has the potential to transmit resistance to many antimicrobials in many circumstances, especially in aquatic environment. The aim of the study was to describe the risk of Shewanella xiamenensis in hospital environment through analysis of genomic comparison and resistance status. Seven S. xiamenensis strains were isolated from hospital wastewater. PCR and Sanger sequencing were carried out for detection of common carbapenemase genes. Antimicrobial susceptibility testing was performed to determine the antimicrobial profile. Whole genome sequencing was applied, and sequences were further used for genomic analysis. Seven Shewanella xiamenensis were all positive for bla NDM and bla OXA-48. Antimicrobial susceptibility testing showed all Shewanella xiamenensis were resistant to cefotaxime, ceftazidime, imipenem, meropenem, gentamycin and trimethoprim-sulfamethoxazole. Whole genome sequencing and phylogenetic analysis demonstrated the diversity of Shewanella xiamenensis despite isolating from one wastewater pool. To the best of our knowledge, this is the first report of detection of three types bla OXA-48-like genes in one hospital in China. And we have detected multi-drug resistant S. xiamenensis from hospital wastewater. This emphasizes that the presence of naturally existing carbapenemases in the environment may be significantly overlooked and that the bla OXA-48-like genes in China may originate through the horizontal gene transfer from S. xiamenensis to Enterobacterales rather than import from other countries.

Hospital-Based Air-Borne and Surface-Borne Bacterial Pathogens and Their Antimicrobial Profiles in Wolaita Sodo, Southern Ethiopia.

It is well documented that hospital environments are the niche/reservoir of many clinically important microorganisms, including multidrug-resistant air-borne and surface-borne pathogens. This problem is the most pressing public health concern, particularly in developing countries like Ethiopia, due to its poor infection management system. This study was planned to detect air-borne and surface-borne bacterial pathogens and their antimicrobial resistance patterns in Wolaita Sodo University Comprehensive Hospital, Southern Ethiopia. A laboratory-based cross-sectional study was conducted from May to July 2021. Swabbing and open-plate sample collection methods were used to collect specimens. Standard bacteriological techniques were used to isolate and identify bacterial pathogens. The Mueller-Hinton agar was used to detect the drug susceptibility pattern of bacteria by using the Kirby-Bauer disc diffusion method. From a total of 323 samples tested, 118 (36.5%) showed the growth of bacteria. The detection rate of bacterial pathogens in the intensive care unit (35.4%) was higher than in operation theater. From the total of 118 bacterial isolates, 39.8%, 27.9%, 20.3%, and 11.5% of S. aureus, P. aeruginosa, Klebsiella pneumoniae, and E. coli, respectively, were surface-borne. Whereas 37%, 25%, 20.83, and 16.6% of S. aureus, P. aeruginosa, Klebsiella species, and E. coli, respectively, were air-borne. S. aureus showed a 19.04 to 80.9% range of antimicrobial resistance to different classes of antibiotics from surface specimens. A 12.5-100% range of antibiotic resistance levels was detected for all Gram-negative surface-borne bacterial pathogens. P. aeruginosa was 66.7%, 73.3%, and 73.3% resistant to gentamicin, chloramphenicol, and ceftriaxone, respectively. K. pneumoniae showed 75% and 87.5% resistance to ceftriaxone and ciprofloxacin, respectively, and a completely ampicillin-resistant E. coli was detected. From a total of 48 bacterial pathogens identified from surfaces in the intensive care unit, 34 (70.8%) developed multidrug resistance. A significant prevalence of surface-borne bacterial pathogens was detected. This study revealed that S. aureus, P. aeruginosa, K. pneumoniae, and E. coli were nosocomial infection concerns of the hospital, and this could be the reason for different types of hospital acquired infections in the study area. A high prevalence of MDR was detected in the most surface-borne bacterial isolates.

Selective antimicrobial food packaging of composite poly(lactic acid) cobalt-citrate films

Food spoilage is a well-known subject in worldwide research, involving a plethora of approaches linked to physical and chemical processes. Poised to develop active antimicrobial packaging materials addressing the specific issue, a composite film was prepared from biocompatible-biodegradable poly(lactic acid) (PLA), incorporating a bioinorganic hybrid metal-organic Co(II)-citrate (Co-cit) complex. The fabricated PLA-(Co-cit) film retained its physicochemical profile as attested to through FT-IR, UV-Visible, SEM, DSC, TGA, nanofocus-confocal microscopy, weight variation, moisture, bending, and mechanical tests, thus justifying further investigation in antimicrobial potency biological experiments. Testing involved Gram-positive/Gram-negative bacteria, revealing a well-defined antimicrobial profile, with clear specificity toward Listeria monocytogenes, thereby asserting proof of concept on the design of such materials. Collectively, the work sets the stage for development of materials conforming to demands of active packaging and employing physicochemically well-defined hybrid metal-organic species, bearing bacteria-specific antimicrobial properties, ultimately contributing to the maintenance of integrity and extension of shelf-life for foods.

Studies on antimicrobial stress with reference to biofilm formation of faecal microbial communities from Apatani tribe of Arunachal Pradesh

PurposeAntibiotic resistant bacteria have created serious health conditions worldwide, disseminating various infections to people and community along with direct clinical implications in therapeutic options. MethodsThe present study analysed 20 samples from human faeces of Apatani tribe, Arunachal Pradesh, India. Biofilm assay, antimicrobial susceptibility tests and antimicrobial profiling were performed along with phylogenetic analysis. ResultsPhenotypic screening indicated the presence of 21 aerobic isolates comprising Escherichia sp 42.8% (n ​= ​9), Citrobacter sp 9.52% (n ​= ​2), Klebsiella sp 23.8% (n ​= ​5) and Enterococcus sp 23.8% (n ​= ​5). Tetracycline, ciprofloxacin, ceftadizime, gentamicine, vancomycin and erythromycin were observed to highly dominate the biofilm producing bacteria. Antimicrobial activity of Escherichia sp, Citrobacter sp, Klebsiella sp, and Enterococcus sp inhibited the growth of at least one of the tested pathogens. Phylogenetic analysis revealed that antibiotic resistant Klebsiella sp belonged to Klebsiella pneumonia; Escherichia sp belonged to Escherichia fergusonii and Escherichia coli; Enterococcus sp belonged to Enterococcus faecium while Citrobacter sp belonged to Citrobacter freundii. ConclusionThe present work shows that antibiotic resistant bacteria-Klebsiella sp, Enterococcus sp, Escherichia sp and Citrobacter sp were highly prevalent in the faecal microbial communities of Apatani tribe from Arunachal Pradesh. Presence of such antibiotic resistance and biofilm formation in faecal microbiota poses serious concerns regarding health and therapeutic options as this tribe mostly resides in remote vicinities of Arunachal Pradesh. Thus, exploring the mechanisms for dissemination of antibiotic resistance in this tribe helped us to identify key factors pertaining to the health of this tribe as well as their environment.

Exploring the Relationships between Structure and Antimicrobial Potency of Quinolinequinones.

Microorganisms are responsible for hospital infections, and methicillin-resistant Staphylococcus aureus is one of them. In looking for the most effective lead structures to cope with the rise of antimicrobial (antibiotic) resistance, we evaluated the antimicrobial profile of quinolinequinones for potential antimicrobial applications. 1,4-quinone molecules fused with heteroatom have been studied extensively for many years as a source of drugs and lead structures. The aims of this study were to evaluate the antimicrobial activity of quinolinequinones against bacterial and fungal strains, and to probe for potential lead structures. For this reason, the activity of these compounds against three different strains of Candida fungi (C. albicans, C. parapsilosis, and C. tropicalis) and Gram-positive and Gram-negative pathogenic bacteria were investigated, searching for potential lead compounds. Five of nine quinolinequinones showed activity mainly against the Gram-positive strains with a minimal inhibitory concentration within the Clinical and Laboratory Standards Institute (CLSI) levels. The results revealed that quinolinequinones have significant activity against bacteria including Staphylococcus aureus and Staphylococcus epidermidis, and fungi including Candida albicans and Candida parapsilosis. QQ1, QQ2, QQ3, QQ5, and QQ6 exhibited the highest growth inhibition against two essential species of the Gram-positive strains (Staphylococcus epidermidis and Staphylococcus aureus). Among these, four molecules (QQ2, QQ3, QQ5, and QQ6) were also active against Enterococcus faecalis, the other member of the Gram-positive strains. The antifungal profile of two quinolinequinones (QQ7 and QQ8) indicated that they were as effective as the reference drug Clotrimazole against Candida albicans. The same molecules also have potential inhibitory antifungal activity against Candida tropicalis. For better understanding, the most active two quinolinequinones (QQ2 and QQ6) were examined for biofilm inhibition and a time-kill kinetic study.

RESISTANCE PATTERN OF ANTIBIOTIC ON RE-EMERGING ESBL PRODUCING Escherichia coli AND Salmonella species ISOLATED FROM DIARRHOEA PATIENT IN TWO HOSPITALS IN ENUGU

Antimicrobial resistance among Enterobacteriaceae is unavoidable in modern medicine, and it is a major concern in the treatment of bacterial infections both in the hospital and in the community. Extended spectrum β-lactamases (ESBL) are enzymes produced by a range of Gram negative bacteria that provide greater antibiotic resistance. This article aims to determine the antimicrobial resistance pattern of re-emerging ESBL producing Enterobacteriaceae isolated from diarrhea patients in Enugu. Its objective is to isolate ESBL producing bacteria, investigate the prevalence of ESBL producing bacteria in patients and determine antimicrobial sensitivity profile. Clinical stool samples were collected from diarrhea patients from two hospitals in Enugu and were isolated on Cysteine Lactose Electrolyte Deficient (CLED) and Salmonella Shigella agar, a total of 35 isolates were obtained from which only 9 isolates were identified as potential Esbl producing organisms after phenotypical method and double disk synergy.

Molecular Epidemiology of Staphylococcus aureus in China Reveals the Key Gene Features Involved in Epidemic Transmission and Adaptive Evolution.

ABSTRACTStaphylococcus aureus is a Gram-positive pathogen that causes various infections in humans and domestic animals. In China, S. aureus is the most common Gram-positive pathogen that causes clinical infections. However, there are few comprehensive genome-based molecular epidemiology studies to investigate the genotypic background of the major S. aureus clones that are epidemic in China. Here, four S. aureus isolates that were recovered from hospital personnel were sequenced. In combination with whole-genome sequencing (WGS) data of 328 S. aureus strains as references, we performed a comprehensive molecular epidemiology study to reveal the molecular epidemic characterization of S. aureus that is epidemic in China. It was found that 332 S. aureus isolates were phylogenetically categorized into 4 major epidemic groups with different epidemiology phenotypes. Each group has exclusive features in virulence genotypic profiles, antimicrobial resistance genotypic profiles, core and pangenome features representing the differences involved in genetic features, evolutionary processes, and potential future evolutionary directions. Moreover, a comparative core genome analysis of 332 S. aureus isolates indicated several key genes that contributed to differences in molecular epidemic characterization and promoted the adaptive evolutionary process of each group. This study provides a comprehensive understanding of molecular epidemiological characteristics and adaptive evolutionary directions of major S. aureus clones that are epidemic in China.IMPORTANCE Staphylococcus aureus is an important Gram-positive pathogen that is epidemic worldwide and causes various infections in humans and domestic animals. However, there has been relatively little research on comprehensive molecular epidemiology in China. In this research, we reconstructed the phylogenetic relationship based on whole-genome data of strains almost all over China, screened for resistance and virulence genes, and took core and pan genome analysis to perform a comprehensive molecular epidemiology study of S. aureus that is epidemic in China. Our results highlight that there are 4 major epidemic groups with different epidemiology phenotypes after phylogenetic categorization with exclusive genetic features in virulence genotypic profiles, antimicrobial-resistance genotypic profiles, and core and pangenome features, and we found key gene features involved in epidemic transmission and adaptive evolution. Our findings are critical in describing molecular characteristic profiles of S. aureus infection, which could update existing preventive measures and take appropriate strategies.

Draft Genome Sequences and Antimicrobial Resistance Genes of Five Staphylococcus aureus Strains Isolated from Bovine Milk.

ABSTRACTStaphylococcus aureus is one of the most important bacterial pathogens causing bovine mastitis, which leads to huge economic losses worldwide. Here, we report draft genome sequences and antimicrobial resistance gene profiles of five Staphylococcus aureus strains that were isolated from bovine milk in Pakistan.

Identification and antimicrobial sensitivity profiling of bacteria isolated from cultured catfish shing (Heteropneustes fossilis)

The cultivated species of catfish (Heteropneustes fossilis), also known as "Shing" has a delectable flavor, a high market value, a high nutritional and therapeutic value, and a high iron and calcium content. In Bangladesh, the shing (H. fossilis) fish is one of the most sought-after, popular, and extremely valuable indigenous species. The purpose of this research was to isolate bacterial pathogens from infected shing (H. fossilis) fish and determine their antibiotic sensitivity. In total, 76 medically infected shing fish were collected by the cultivators from their own ponds in the Jashore district, in southern Bangladesh. Disease-causing bacteria were found in 62 (81.5%) of the infected fish, while normal flora were found in 14 (18.5%) of the 76 samples. There were 62 pathogenic bacterial isolates found, and Aeromona spp., Pseudomonas spp., Streptococcus spp., Flavobacterium spp. and Vibrio spp. were the main causes of disease in the sick fish. Among the species of bacteria that were isolated, the prevalence of the largest pathogens, Aeromonas spp. was 34 (51.4%) and the prevalence of the second largest, Pseudomonas spp. was 13 (20.3%). The other isolates were comprised of the following species: Streptococcus spp. 9 (9.4%), Flavobacterium spp. 4 (5.4%) and Vibrio spp. 2 (4.1%). The farming of shing (H. fossilis) fish has been increased rapidly all around the country. Therefore, bacterial infections may reduce the production of fish in ponds. In this research, bacterial strains showed a high degree of sensitivity to ciprofloxacin (77%) and levofloxacin (54%). Significantly, oxytetracycline (52%) enrofloxacin (45%) and erythromycin (45%) were the intermediate/moderate sensitive antibiotics. All the strains were found to be resistant to amoxicillin 57/62 (92%) and neomycin 42/62 (68%). The findings of this research will be beneficial to fish farmers in the treatment of bacterial infections in fish, as these diseases are caused by microorganisms. The PCR method might be studied further as a means of identifying all bacterial cultures, which would require additional research.

P282 Bacterial co-infections in Mucormycosis infected COVID-19 patients: experience from a tertiary care center in India

Poster session 2, September 22, 2022, 12:30 PM - 1:30 PMDuring the second wave of COVID-19 in India, there was a deluge in Mucormycosis cases; which posed a serious threat as both conditions require extended hospital stay thus serving as an ideal setting for secondary infections.Objectives1. To ascertain the prevalence and anti-microbial profile of hospital-acquired secondary infections in COVID- 19 patients with Mucormycosis.2. To evaluate the outcome in these patients and compare it with the outcome of COVID-19 patients with Mucormycosis but without any other secondary infection.MethodsA 2-month retrospective observational study was conducted, where we compared outcomes in two groups of COVID-19 patients with Mucormycosis, one group being patients with secondary infections and the other group including patients without secondary infections.A total of 180 samples from suspected cases of Mucormycosis, that underwent evaluation by conventional methods, KOH mount and cultures on SDA, were included. Fungal pathogens were identified from the positive cultures, based on macroscopic and microscopic features, as per standard Mycological methods.Secondary infections inpatients were studied based on conventional bacteriological culture, microbiological profile, along-with identification and antibiotic susceptibility by VITEK 2. PCT and CRP values were also compared. The outcome was then evaluated. Data analysis was done using SPSS V-20.ResultsA total of 55 patients out of 140 patients, tested positive for Mucormycosis, either by KOH, culture or both. Rhizopus arrhizus was the most common isolate identified.A total of 12/55 (21.8%) people with Mucormycosis developed secondary infections during their stay in the hospital, bloodstream infection being the most common (7/15; 46.67%). Overall, gram-negative (GN) organisms were more common (11/16; 68.75%), in comparison to Gram Positives (GP) (5/16; 31.25%), but the most common organism isolated was Enterococcus faecium (5/16; 31.25%), followed by Klebsiella pneumoniae (4/16) and E. coli (4/16). A total of 4/5 isolates (80%) of Enterococcus faecium were multi-drug resistant (MDR) and two of them were vancomycin-resistant. In all, 10/11 GN isolates (90.9%) were MDR, high resistance to carbapenems was observed, nine out of 11(81.81%) isolates were resistant to imipenem and eight (72.72%) were resistant to meropenem. A total of 3/12 (25%) patients succumbed to their infection in the group with secondary infections, after an average length of stay of 23.33 days. The most common cause of death in these patients was septic shock. A total of 8/43 (18.6%) succumbed to their infection in the group without any secondary infection at an average stay of 9.12 days in the hospital. CRP was found to be consistently elevated, this biomarker might not have a predictive value for bacterial infections in COVID-19 but PCT had a positive predictive value for the secondary bacterial infections overall (P-value <.001). Length of stay in hospital co-related with the development of secondary infection and mortality (P-value <.001).ConclusionCulture-based testing should be carried out before the administration of anti-microbials. PCT can be used as a guiding tool. Controlled use of antibiotics along with periodic surveillance and hand hygiene practices will immensely contribute to infection control.

Clostridium perfringens associated with dairy farm systems show diverse genotypes

Clostridium perfringens is a bacterial species of importance to both public and animal health. Frequently found in food system environments, it presents a risk to food animal health such as dairy herds, and may cross contaminate associated ingredients or food products, with potential to cause sporadic and outbreaks of disease in human populations, including gastroenteric illness. In this study, we characterized C. perfringens isolated from bovine, caprine, and ovine dairy farm systems (n = 8, 11 and 4, respectively). Isolates were phenotypically screened for antimicrobial sensitivity profiling, and subjected to whole genome sequencing to elucidate related genetic markers, as well as examine virulence gene markers, mobile genetic elements, and other features. Both toxin type A and type D isolates were identified (78 % and 22 % of isolates, respectively), including 20 novel sequence types. Resistance to clindamycin was most prevalent among antibiotics screened (30 %), followed by erythromycin (13 %), then penicillin and tetracycline (4 %), although an additional 3 isolates were non-susceptible to tetracycline. Most isolates harboured plasmids, which mobilised virulence markers such as etx, cpb2, and resistance markers tetA(P), tetB(P), and erm(Q), on conjugative plasmids. The presence of type D isolates on caprine farms emphasizes the need for control efforts to prevent infection and potential enterotoxemia. Clostridium perfringens enterotoxin (cpe) was not identified, suggesting lower risk of gastrointestinal illness from contaminated foods, the presence of other virulence and antimicrobial resistance markers suggests farm hygiene remains an important consideration to help ensure food safety of associated dairy foods produced.