Alternative Antibiotics Research Articles

Effects of antibiotic, acidifier, and probiotic supplementation on mortality rates, lipoprotein profile, and carcass traits of broiler chickens

Antimicrobial resistance is a significant issue, therefore it's relevant to assess the effects of antibiotics, acidifiers, and probiotic supplementation finding a good alternative to reduce the use of antibiotics in broiler production in rural areas of Bangladesh. Using randomized control trial, this 28-day study evaluated 360 Hubbard Classic broiler chicks divided into four groups: oxytetracycline-treated, acidifier-treated, Lactobacillus-based probiotic-treated, and control (no antibiotics, acidifiers, or probiotics). Each group was replicated three times with 30 birds each with adlibitum feeding. Body weight and feed intake were recorded weekly, and on 28th day, carcass traits and blood lipoprotein levels were evaluated. Results showed that in first and fourth weeks, the body weight gain significantly varied in probiotics and acidifier-treated birds than the control group (P < 0.001). The probiotic group had gained considerable increase in body weight (185.0 g vs 161.7 g and 1745.0 g vs 1592.7 g) than the control group. Notably, in the first week, the feed conversion ratio for the probiotic group was 0.76, but the antibiotic group's was 0.96 (P < 0.001). The weights of the drumstick (88.33 g) and liver (61.0 g) having probiotic supplements were substantially higher than those in the control group (77.0 g and 51.33 g, respectively) (P < 0.001). According to serum lipoprotein analysis, the probiotic and acidifier groups exhibited lower LDL levels (71.1 mg/dl and 69.8 mg/dl, respectively) and higher triglyceride levels (122.9 mg/dl and 135.4 mg/dl). These findings highlight the potential of probiotics and acidifiers as effective antibiotic alternatives, promoting carcass traits and lowering LDL levels in broilers in Bangladesh.

1824. Impact of Social Determinants of Health on Preferred Treatment of Trichomonas vaginalis and Chlamydia trachomatis

Abstract Background The 2021 CDC Sexually Transmitted Infections (STI) Treatment Guideline modified preferred therapy for Trichomonas vaginalis (TV) and Chlamydia trachomatis (CT) from single dose to a 7-day course. Social Determinants of Health (SDOH) are non-medical factors that influence a person’s life; little is known regarding the association between SDOH and TV and CT treatment. The study objective was to evaluate treatment of TV and CT infections after the guideline update and determine if health inequities exist with use of preferred therapy. Methods IRB approved, retrospective cohort of patients ≥ 15 years with confirmed diagnosis of uncomplicated TV or CT in outpatient settings. Excluded: pregnant/nursing, allergy to preferred therapy, unable to take oral. Primary outcome: proportion who received guideline preferred vs non-preferred (alternative, discordant, or null) antibiotic therapy. Logistic regression was used to identify variables associated with preferred treatment; SDOH were exposures of interest. Secondary outcomes: test of cure (≤ 3 months), any repeat positive test (recurrence/reinfection), any retreatment, expedited partner therapy (EPT) offered. A sample of 712 patients was needed to detect a 10% difference between two exposures (α=0.05, β=0.2). Results 473 (66%) patients received preferred therapy; patient characteristics are in Table 1. Patients &amp;lt; 25 years had more asymptomatic disease compared to older patients (198 [54%] vs 150 [44%], P=0.01). Patients who received Emergency Department (ED) care were more likely to receive preferred therapy compared to outpatient clinics (201/264 [76%] vs 272/448 [61%], P=&amp;lt; 0.001). Black race, lower median income, and public insurance covaried with ED care. After adjusting for female sex, receipt of ED care was independently associated with preferred therapy (Table 2). 181 (25%) patients had 3-month test of cure performed; repeat positive test/retreatment was more frequent in patients who received non-preferred therapy (25 [11%] vs 24 [5%], P=0.01). EPT was offered in 35 (7%) and 8 (3%) patients in the preferred and non-preferred groups (P=0.03).Table 2:Variables Associated with Receipt of Preferred Therapy. Abbreviations: ED, Emergency Department; UnAdjOR, unadjusted odds ratio; AdjOR, adjusted odds ratio Conclusion Preferred therapy was more frequent in patients who received ED care. EDs represent an important safety net and provide high-level care for patients with SDOH barriers. Disclosures Erin Eriksson, PharmD, BCPS, BCIDP, Stryker Corp: Stocks/Bonds Indira Brar, MD, Gilead: Advisor/Consultant|Gilead: Grant/Research Support|Gilead: Honoraria|Janssen: Grant/Research Support|Janssen: Honoraria|ViiV: Advisor/Consultant|ViiV: Grant/Research Support|ViiV: Honoraria Michael Veve, PharmD, MPH, National Institutes of Health: Grant/Research Support|Paratek Pharmaceuticals: Grant/Research Support

1643. Journey Mapping Penicillin Allergies in Children: Parental Experiences, Care Gaps, and Suggestions Offered by Parents to Address Unmet Needs

Abstract Background Penicillin allergies are commonly reported in children but rarely true and perpetuate the use of alternative antibiotics. Leading allergy societies recommend a proactive approach to penicillin allergy delabeling. We use patient journey mapping to identify opportunities to improve the delabeling of penicillin allergies in children before, during, and after a child’s initial reaction to penicillin. Methods Mapping was conducted via a secondary analysis of a qualitative study consisting of 18 interviews with parents recruited via social media reporting a penicillin allergy in their child. Two researchers coded interviews using a directed content analysis to capture parent’s experiences before, during, and after their child’s penicillin reaction. We describe the common experiences of parents ( &amp;gt;9 participants). Results Pre-reaction, parents reported a lack of awareness regarding potential reactions children may experience when taking penicillin. Intra-reaction, parents reported their child’s provider suspected their child’s reaction was due to a penicillin allergy, wrote the child’s reaction in the medical record, and suggested or advised that penicillin be avoided in the future without mention of the availability of penicillin allergy testing. Post-reaction, parents remained unaware of the availability of penicillin allergy testing and uninformed of the implications of penicillin allergies on their child’s care. To better engage parents in penicillin allergy testing, participants suggested that providers inform parents of: 1) potential reactions their child may experience at the time of penicillin prescription (pre-reaction); 2) the availability of penicillin allergy testing to confirm the presence of true allergy (intra-reaction); and 3) penicillin allergy testing procedures and the benefits of penicillin allergy testing for their child’s health (post-reaction), see Table 1. Conclusion Using patient journey mapping, we describe the common experiences of parents concerning their child’s penicillin allergy, gaps in care parents experienced, and suggestions offered by parents to address their unmet care needs. These findings may inform future efforts to improve the delabeling of penicillin allergies in children. Disclosures Sherry Pagoto, PhD, Astellas Pharmaceuticals: Scientific Advisor|Weight Watchers, International,: Scientific Advisor

2590. Efficacy of Doxycycline Versus Azithromycin in Community Acquired Pneumonia

Abstract Background Guideline-based CAP treatment has consisted of 2 preferred regimens: a beta lactam with a macrolide (azithromycin), or monotherapy with fluoroquinolone or beta lactam with doxycycline as an alternative regimen. While doxycycline may represent a more attractive option due to concerns for increased cardiovascular risks associated with azithromycin, individual trials assessing efficacy Methods Individuals over 18, admitted for greater than 48 hours at NYU Brooklyn, NYU Long Island, and NYU Tisch from January 1, 2019 to December 31, 2022 with clinical or radiographic evidence of pneumonia treated with ceftriaxone plus either azithromycin or doxycycline were included. Subjects were excluded if received alternative antibiotics for &amp;gt;24 hours, were hospitalization for &amp;gt;48 hours within the last 90 days, were pregnant or breastfeeding, had history of structural lung disease, active lung cancer, suspected tuberculosis, or bloodstream infections, immunocompromising condition, ventilated, or with non-infectious cause of pulmonary infiltrates. Results A total of 91 patients met inclusion criteria, 42 patients in the azithromycin group and 49 patients in the doxycycline group. Primary outcomes defined as treatment failure requiring broadening of antibiotics, all-cause inpatient mortality and time to clinical stability were similar between the groups. In the azithromycin group, 11.9% of patients required broadening antibiotics compared to 6.12% in the doxycycline group (p=0.46). Time to clinical stability was 3 in the azithromycin group versus 3.14 days (p=0.6) in the doxycycline group. Secondary outcomes including time to hospital discharge, time to stepdown to oral antibiotics and length of treatment had no difference between groups. There was no difference in safety outcomes between groups. Conclusion Azithromycin and doxycycline were comparable in terms of efficacy and safety when treating CAP. These findings can be added to the existing body of evidence supporting doxycycline as an attractive option for atypical CAP coverage. Disclosures All Authors: No reported disclosures

2263. Amoxicillin Use for Common Acute Respiratory Infections During a National Shortage: Results from the SHARPS-OP Benchmarking Collaborative

Abstract Background Amoxicillin is a first-line agent for most pediatric acute respiratory infections (ARIs). In Fall 2022, a nationwide amoxicillin shortage occurred. This study sought to provide precise estimates in outpatient amoxicillin usage during the shortage, using a nationally representative sample of institutions providing pediatric care. Methods Twenty-two institutions from the Sharing Antimicrobial Reports for Pediatric Stewardship Outpatient (SHARPS-OP) Collaborative provided aggregate quarterly data from Jan 2019 - Dec 2022. Data included total counts of encounters with an ARI ICD-10 code and proportions of ARIs treated with any oral antibiotic, amoxicillin, and azithromycin. Data were stratified by location type (Emergency Department [ED], Urgent Care [UC], and primary care clinics [PCC]). We compared ARI prescribing (ARI encounters resulting in any antibiotic prescription) and the amoxicillin and azithromycin indices (ARI encounters resulting in amoxicillin or azithromycin prescription out of ARI encounters resulting in any antibiotic prescription) between pre-shortage (Jan 2019 - Sep 2022) and shortage (Oct 2022 - Dec 2022) time periods by location type. Results A total 4.89 million ARI encounters (4.24 million during pre-shortage and 0.65 million during the shortage) were reported across 22 institutions. Overall antibiotic prescribing for ARI encounters changed slightly from pre-shortage to shortage period for ED (28.7% to 22.6%; delta: -6.1 [-6.4, -5.8]), UC (41.1% to 39.6%; delta: -1.6 [-1.8, -1.3]) and PCC (38.1% to 38.1%; delta: 0.03 [0.001, -0.003]). Substantial declines in the amoxicillin index were observed for ED (76.1% to 60.9%; delta: -15.1 [-15.8, -14.5]), UC (71.9% to 60.1%; delta: -11.7 [-12.1, -11.3]) and PCC (63.9% to 53.3%; delta: -10.6 [-14.2, -9.6] with considerable variation within and between SHARPS-OP institutions (Figure 1). Azithromycin use among ARI encounters decreased slightly during the amoxicillin shortage (-0.3% [-0.38%, -0.20%]).Figure 1:Amoxicillin indices for pre-shortage and amoxicillin shortage time periods for included SHARPS-OP institutions, stratified by location type.Location types: Emergency Department [ED]; Urgent Care [UC]; Primary Care Clinic [Primary] Conclusion Amoxicillin utilization disproportionately decreased compared to overall antibiotic prescribing for ARIs during the shortage. Providers may have prescribed alternative antibiotics rather than no therapy for ARIs. Disclosures Michael J. Smith, M.D., M.S.C.E, Merck: Grant/Research Support|Pfizer: Grant/Research Support Bethany A. Wattles, PharmD, MHA, Merck: Grant/Research Support

Integrating network pharmacology and experimental validation to explore the mechanisms of luteolin in alleviating fumonisin B1–induced intestinal inflammatory injury

Contamination with fumonisin B1 (FB1) represents a global health problem. FB1 exposure may also trigger intestinal injury by activating inflammatory responses, leading to a reduction in production performance and economic benefits. However, the mechanism of FB1-induced intestinal inflammatory injury is still unclear. At the same time, it is urgent to develop antibiotic alternatives and therapeutic targets to alleviate antibiotic resistance and to ensure effective treatment of intestinal inflammatory injury. We combined network pharmacology and in vitro experiments to explore the core therapeutic targets and potential mechanism of luteolin in FB1-induced intestinal inflammatory injury. Network pharmacology and molecular docking revealed that nuclear factor kappa B (NF-κB) p65, extracellular signal-regulated kinase (ERK), interleukin 6 (IL-6) and IL-1β are the important targets, and the NF-κB and ERK signalling pathways are critical in FB1-induced intestinal inflammatory injury. Besides, in vitro experiments further demonstrated that luteolin can inhibit FB1-induced intestinal inflammatory injury by inhibiting activation of the NF-κB and ERK signalling pathways and reducing the expression of IL-6 and IL-1β in IPEC-J2 cells. We have comprehensively illustrated the potential targets and molecular mechanism by which luteolin can alleviate FB1-induced intestinal inflammatory injury. Luteolin may be an effective antibiotic alternative to prevent intestinal inflammatory injury.

Distinct mode of action of a highly stable, engineered phage lysin killing Gram-negative bacteria.

Engineered lysins are considered as highly promising alternatives for antibiotics. Our previous screening study using VersaTile technology identified 1D10 as a possible lead compound with activity against Acinetobacter baumannii strains under elevated human serum concentrations. In this manuscript, we reveal an unexpected mode of action and exceptional thermoresistance for lysin 1D10. Our findings shed new light on the development of engineered lysins, providing valuable insights for future research in this field.

Phage-induced bacterial morphological changes reveal a phage-derived antimicrobial affecting cell wall integrity.

In a looming post-antibiotic era, antibiotic alternatives have become key players in the combat against pathogens. Although recent advances in genomic research allow scientists to fully explore an organism's genome in the search for novel antibacterial molecules, laborious work is still needed in order to dissect each individual gene product for its antibacterial activity. Here, we exploited phage-induced bacterial morphological changes as anchors to explore and discover a potential phage-derived antimicrobial embedded in the phage genome. We found that, upon vibriophage KVP40 infection, Vibrio parahaemolyticus exhibited morphological changes similar to those observed when treated with mecillinam, a cell wall synthesis inhibitor, suggesting the mechanism of pre-killing that KVP40 exerts inside the bacterial cell upon sieging the host. Genome analysis revealed that, of all the annotated gene products in the KVP40 genome that are involved in cell wall degradation, lytic transglycosylase (LT) is of particular interest for subsequent functional studies. A single-cell morphological analysis revealed that heterologous expression of wild-type KVP40-LT induced similar bacterial morphological changes to those treated with the whole phage or mecillinam, prior to cell burst. On the contrary, neither the morphology nor the viability of the bacteria expressing signal-peptide truncated- or catalytic mutant E80A- KVP40-LT was affected, suggesting the necessity of these domains for the antibacterial activities. Altogether, this research paves the way for the future development of the discovery of phage-derived antimicrobials that is guided through phage-induced morphological changes.

A retrospective case-control study to evaluate the use of beta-lactam desensitization in the management of penicillin-allergic patients: a potential strategy for Antimicrobial Stewardship Programs.

Introduction: Penicillin allergy labels (PAL) are common in the hospital setting and are associated with worse clinical outcomes. Desensitization can be a useful strategy for allergic patients when alternative options are suboptimal or not available. The aim was to compare clinical outcomes of patients with PAL managed with antibiotic desensitization vs. those who received alternative non-beta-lactam antibiotic treatments. Methods: A retrospective 3:1 case-control study was performed between 2015-2022. Cases were adult PAL patients with infection who required antibiotic desensitization; controls were PAL patients with infection managed with an alternative antibiotic treatment. Cases and controls were adjusted for age, sex, infection source, and critical or non-critical medical services. Results: Fifty-six patients were included: 14 in the desensitization group, 42 in the control group. Compared to the control group, desensitized PAL patients had more comorbidities, with a higher Charlson index (7.4 vs. 5; p = 0.00) and more infections caused by multidrug-resistant (MDR) pathogens (57.1% vs. 28.6%; p = 0.05). Thirty-day mortality was 14.3% in the desensitized group, 28.6% in the control group (p = 0.24). Clinical cure occurred in 71.4% cases and 54.8% controls (p = 0.22). Four control patients selected for MDR strains after alternative treatment; selection of MDR strains did not occur in desensitized patients. Five controls had antibiotic-related adverse events, including Clostridioides difficile or nephrotoxicity. No antibiotic-related adverse events were found in the study group. In multivariate analysis, no differences between groups were observed for main variables. Conclusion: Desensitization was not associated with worse clinical outcomes, despite more severe patients in this group. Our study suggests that antibiotic desensitization may be a useful Antimicrobial Stewardship tool for the management of selected PAL patients.

The performance of plant essential oils against lactic acid bacteria and adverse microorganisms in silage production.

Plant essential oils have played an important role in the field of antibiotic alternatives because of their efficient bacteriostatic and fungistatic activity. As plant essential oils are widely used, their activity to improve the quality of plant silage has also been explored. This review expounds on the active ingredients of essential oils, their bacteriostatic and fungistatic activity, and mechanisms, as well as discusses the application of plant essential oils in plant silage fermentation, to provide a reference for the development and application of plant essential oils as silage additives in plant silage fermentation feed.

Porous silicon microneedle patches for delivery of polymyxin‐based antimicrobials

AbstractThere is a global trend of increasing antibiotic resistance to Gram‐negative bacteria and the medical research community is looking for alternative antibiotics. Antibiotics such as polymyxin B (PMB) show excellent efficacy and low resistance rates against Gram‐negative bacteria. The topical administration of PMB, however, has clinical limitations such as minimal residence time, making it difficult for its use to treat skin infections. Here, we present porous silicon microneedle (pSi MN) patches to deliver PMB to the skin. pSi MN patches are fabricated by, first, generating the projections by dry Si etching techniques, followed by an electrochemical etching to create porous layers around the MNs. After loading PMB into the porous layer, the antibacterial activity of pSi MNs is determined by measuring the inhibition zone of Gram‐negative Escherichia coli. Next, PMB is efficiently delivered into the epidermal layer of ex vivo skin models, as confirmed by chemical mapping using matrix‐assisted laser desorption/ionization mass spectrometry imaging (MALDI‐MSI). The results demonstrate that pSi MN patches are an efficient and versatile tool for the transdermal delivery of PMB with maintained bioactivity and antimicrobial efficacy, thus expanding the possibilities of current transdermal drug delivery systems.

PSV-26 Use of Garlic Drench in the Modulation of Galectin Gene Expression in St Croix Sheep

Abstract St. Croix sheep are parasite resistant and can live in a wide variety of climates. Dietary supplements can influence innate immunity. Garlic (Allium sativum) is used as an immune modulator and an alternative antibiotic. Lectins in garlic could interfere with animal lectins such as Galectins (Gals). Galectins bind β-galactosides and modulate pathological processes and immunity. The effect of garlic drench on Gal (1,3,9) gene expression in sheep blood was evaluated. All protocols were approved by the IACUC. Clinically healthy, adult St. Croix sheep were divided into two groups. The treatment group (n = 6) was drenched with 5 mL garlic barrier at a rate of 10 mL diluted in sterile distilled water 1:1. The control group (n = 6) was drenched with 10 mL sterile distilled water for four weeks. Cells and plasma were separated by centrifugation of whole blood. The concentration of total plasma protein was determined using the BCA assay kit (Pierce). Secretion of Galectins 1,3,9 was evaluated using Sheep-specific ELISA(My-BioSource). Data were analyzed using SAS Statistical analysis software 9.4 (SAS Institute). Nucleic acid purity and concentrations were assessed using the Nanodrop spectrophotometer. Galectin gene transcription was evaluated using sheep Gal 1,3 and 9 specific primers commercially sequenced (Eurofins Genomics). The house keeping genes, Ribosomal Protein Lateral Stalk Subunit P0 and Ubiquitin C-Terminal Hydrolase L5, were used as internal controls. Samples were amplified in duplicate using the CFX Connect real-time PCR system. The Livak Method was used to calculate the fold change in gene expression. Galectin 1, 3, and 9 were transcribed and translated. Transcription and translation were differentially affected by garlic. Galectin 1 transcription increased; secretion decreased. Galectin 3 transcription and secretion increased at P &amp;lt; 0.05. There was no change in the transcription of galectin 9, however, secretion was increased. Thus, garlic drench deferentially impacted transcription and secretion of structurally distinct Gal in sheep blood. Further studies are needed to determine the effect of Garlic on Gal-mediated functions important to sheep health and production.

PSXIII-10 Effects of Dietary Lactobacillus Reuteri on Growth Performance, Frequency of Diarrhea, and Blood Biochemical Parameters of Weaned Pigs

Abstract Weaning stress of pig causes reduction of growth performance and high risk of diseases. These effects are directly connected to economic losses. Antibiotic growth promotors commonly used for improving the negative effects of weaning stress of pigs, but are banned for public health concerns. Therefore, probiotics can be one potential of an antibiotic alternative. Dietary Lactobacillus reuteri is one of the strains of probiotics which has the ability to enhance growth performance of animals. This study was conducted to investigate the effects of dietary Lactobacillus reuteri on growth performance, frequency of diarrhea, and biochemical parameters of weaned pigs. A total of 48 weaned pigs [Duroc × (Landrace × Yorkshire); initial body weight (BW) = 6.51 ± 0.87 kg; 21 days old)] were randomly assigned to two dietary treatments (4 pigs/pen; 6 replicates/treatment) and fed for 4 weeks in a randomized complete block design (block = initial BW and sex). Dietary treatments consisted of a basal weaner diet (CON) and CON supplemented with 0.02% Lactobacillus reuteri IDCC 3701 (LR; ILDONG Bioscience Co., Ltd., Pyeongtaek, Republic of Korea). The frequency of diarrhea was calculated daily during two weeks in each pen with optical diarrhea scores. The scoring of diarrhea was from 1 to 5, and a score of over 4 was considered diarrhea. Blood samples were obtained from randomly selected one pig per pen at the end of the experiment. Sera were obtained from the blood sample to measure the blood biochemical parameters using the specific kits and a clinical auto-analyzer. All data were analyzed using PROC GLM of SAS. The experimental unit was a pen. Statistical model for growth performance and blood biochemical parameters included dietary treatments as a main effect and initial BW as a covariate. The frequency of diarrhea was analyzed by the Chi-square test. Pigs fed LR increased (P &amp;lt; 0.05) average daily gain from day 1 to 7 and 15 to 28 and gain to feed ratio from day 1 to 7 compared with those fed CON. Pigs fed LR tended to have reduced (P &amp;lt; 0.10) frequency of diarrhea during the first two weeks of experiment than those fed CON. In addition, pigs fed LR tended to have greater (P &amp;lt; 0.10) serum alanine aminotransferase than those fed CON, but no differences were observed in other blood biochemical parameters. In conclusion, addition of dietary Lactobacillus reuteri in weaner diet improved growth performance, reduced the frequency of diarrhea, and modulated the blood biochemical parameters of weaned pigs.

In situ forming hydrogel loaded with predatory bacteria treats drug-resistant corneal infection

The development of potent bactericidal antibiotic alternatives is important to address the current antibiotic crisis. A representative example is the topical delivery of predatory Bdellovibrio bacteriovorus bacteria to treat ocular bacterial infection. However, the direct topical use of B. bacteriovorus suspensions has the problem of easy loss and inactivation. Here, a B. bacteriovorus in situ forming hydrogel (BIG) was constructed for the ocular delivery of B. bacteriovorus. BIGs, as a fluid in their primitive state, were temperature- and cation- dually sensitive, which was rapidly transformed into immobile gels in the ocular environment. BIGs not only kept the activity of B. bacteriovorus but also retained on the ocular surface for a long time. The biosafety of BIGs was good without HCEC cell toxicity and hemolysis. More importantly, BIGs highly inhibited the growth of drug-resistant Pseudomonas aeruginosa whether in vitro or in the infected rat eyes. The ocular infection was completely controlled by BIGs with no corneal ulcers and inflammations. This living bacteria gel is a promising medication for the local treatment of drug-resistant bacteria-induced ocular infection.

Treatment of bacterial sexually transmitted infections in Europe: gonorrhoea, Mycoplasma genitalium, and syphilis.

This review explores the therapeutic challenges of sexually transmitted infections (STI) in Europe, which include increasing antimicrobial resistance and limited progress in drug discovery. We primarily focus on gonorrhoea, Mycoplasma genitalium, and syphilis infections. For gonorrhoea with escalating resistance rates we explore the possibility of combining ceftriaxone with another antibiotic or using alternative antibiotics to mitigate resistance emergence, and we provide insights on the ongoing evaluation of new antimicrobials, like gepotidacin and zoliflodacin. In the case of M. genitalium, which exhibits high resistance rates to first and second-line treatments, we emphasize the importance of resistance-guided therapy in regions with elevated resistance levels, and highlight the limited alternative options, such as pristinamycin and minocycline. Furthermore, we address the challenges posed by syphilis, where the primary treatment consists of penicillin or doxycycline, with challenges arising in neurosyphilis, allergy, pregnancy, and supply shortages and discuss the ongoing evaluation of alternative antimicrobials (e.g., ceftriaxone, cefixime, linezolid). Our findings identify priority actions and provide concrete solutions for long-term effective management of STIs and antimicrobial resistance mitigation.

Evaluating the Use of Meropenem in Hematologic Patients with Febrile Neutropenia: A Retrospective Observational Single-Cohort Study.

Abstract&#x0D; Objectives &#x0D; The Antibiotic Stewardship Team of Meander Medical Centre (Meander MC) instigated a revaluation of its treatment protocol for hematologic patients admitted with febrile neutropenia. The current hospital protocol advises administering meropenem for 72 hours, followed by antibiotic therapy guided by microbiological cultures. In order to responsibly adjust the current empiric regimen, this study aimed to determine the frequency of bacteria resistant to alternative antibiotics, namely ceftazidime and piperacillin/tazobactam, in both surveillance and diagnostic cultures.&#x0D; Methods&#x0D; This retrospective, observational, single-centre study included adult patients with a hematologic malignancy and febrile neutropenia admitted between October 2018 and June 2021. Collected metadata included patient characteristics, surveillance and diagnostic culture results, and antibiotic use.&#x0D; Results&#x0D; A total of 100 patients were included. One or more bacteria resistant to ceftazidime or piperacillin/tazobactam were identified in blood and urine cultures in seven (7%) and one (1%) patients respectively.&#x0D; Conclusions&#x0D; Our results support the safe reduction of the use of meropenem by changing the empiric treatment protocol for patients with hematologic malignancy and febrile neutropenia. As this study showed a lower resistance frequency to piperacillin/tazobactam than to ceftazidime, this antibiotic is the recommended alternative.

277 Effect of Mode of Delivery of Fecal Microbiota Transplants on Growth Performance and Gut Microbiome in Weaning Piglets

Abstract Weaning is one of the most stressful events for piglets, due to diet change from sow milk to grain-based feed. This diet change causes turnover of the gut microbial which can allow proliferation of pathogens leading to diarrhea. Antibiotics are administered to treat or prevent post-weaning diarrhea (PWD). Increased occurrence of antimicrobial resistance has increased incentives to develop viable antibiotic alternatives. Previous studies have shown that fecal microbiota transplant (FMT) reduced diarrhea incidence and improved body weight gain in piglets. However, one barrier to FMT adoption in swine production is that FMT are generally given via oral gavage, which is difficult and labor intensive for large swine operations. For FMT to be a viable option in swine management, a simple method is needed to administer the transplant. The objective of this study was to determine the effect of three methods of FMT administration (oral, rectal and lyophilized in-feed) on growth performance, diarrhea incidence and gut microbiome. We hypothesize that FMT (in-feed and rectal) will increase colonization efficiency, improve growth performance and reduce diarrhea incidence compared with control. Weaned male piglets (n = 40) were allotted to 4 treatments at 10 piglets per treatment (no FMT - Control, Oral gavage - FMT1, rectal gavage - FMT2 and lyophilized in-feed – FMT3). Feces from 12-week-old pigs, screened for pathogens, was donor material. The study lasted nine days and FMT was for five days. Diarrhea incidences and body weight were observed for the first week. Fecal samples were collected on days 0, 2, 5 and 7. Five piglets per group were sacrificed on day 4 and the remaining on day 8. Cecal and colon contents were collected from the sacrificed piglets. DNA was extracted from fecal and digesta samples and 16S rRNA gene libraries (V4 region) were prepared for bacterial community analysis. Data were analyzed with one-way ANOVA in R. All FMT groups had significantly greater body weight on day 3 (P &amp;lt; 0.05) and average daily gain between day 0 – 3 (P &amp;lt; 0.05) compared with control but there was no difference between FMT groups. There was no effect of FMT on average daily feed intake and diarrhea incidence. Only FMT3 had greater alpha diversity (Observed features and Faith’s phylogenetic diversity) on day 5 (P &amp;lt; 0.05) compared with control, but there was no difference in beta diversity between FMT groups. There was decreased abundance of 27 ASVs (amplicon sequence variant) and increased abundance of 30 ASVs in increased in FMT3 compared with control on day 5. In conclusion, the three FMT groups has similar colonization pattern but there was no difference in diarrhea incidence. FMT3 (lyophilized in-feed) altered overall community structure of piglets and modulated individual taxa.

Dietary Paenibacillus polymyxa AM20 as a new probiotic: Improving effects on IR broiler growth performance, hepatosomatic index, thyroid hormones, lipid profile, immune response, antioxidant parameters, and caecal microorganisms

The search for a natural antimicrobial agent is ongoing and critical because of the rise and rapid proliferation of antibiotic-resistant pathogenic bacteria. The current study aims to examine the effect of Paenibacillus polymyxa AM20 as an alternative antibiotic and feed additive on Indian river broiler performance, digestive enzymes, thyroid hormones, lipid profile, hepatosomatic index, immunological response, gut bacteria, and antioxidant parameters. The bacterial isolate AM20 was identified at the gene level by isolating DNA and using PCR to detect genes. Based on 16S rRNA gene sequence analysis, the bacterial isolate was identified as Paenibacillus polymyxa. One hundred twenty Indian river broilers (1-day old) were randomly divided into 4 groups of 10 chicks each, with 3 replicates. The control group was fed a basal diet only, while the other 3 were administered control diets supplemented with P. polymyxa at 3 concentrations: 0.5, 1, and 1.5 mg/kg. The findings revealed that all groups that received graded amounts of P. polymyxa increased all growth parameters throughout the study. P. polymyxa treatment at 1.5 mg/kg increased body gain by 9% compared to the control due to increased feed intake (P = 0.0001), growth rate (P = 0.0001), and decreased feed conversion ratio. Compared to the control group, P. polymyxa (1.5 mg/kg) enhanced kidney functions in chickens by reducing uric acid and creatinine levels (P = 0.0451). Compared to the control group, alanine aminotransferase and aspartate transaminase levels in the liver were significantly reduced at all P. polymyxa doses. Liver function values were highest for P. polymyxa at 1.5 mg/kg. Compared to the control group, those whose diets included P. polymyxa had significantly better blood cholesterol levels, high-density lipoprotein, low-density lipoprotein, immunological response, thyroid function, and gut microbiota. In general, broiler chickens' economic efficiency was improved by including P. polymyxa in their diet, which also improved their growth performance, carcass dressing, specific blood biochemical levels and enzymes, and the composition of the gut microbiota.

Detection of multidrug resistant Vibrio parahaemolyticus and anti-Vibrio Streptomyces sp. MUM 178J

The growing global population has increased the demand for seafood, making the aquaculture industry a vital food source. However, climate change has negatively impacted the industry as natural inhabitants of aquatic environments such as Vibrio parahaemolyticus are thriving in the warming waters. These foodborne pathogens can cause disease in marine animals, resulting in lowered production rates and substantial economic losses. V. parahaemolyticus is transmitted from these marine animals in aquaculture to humans via raw or undercooked seafood, resulting in gastroenteritis outbreaks. In addition, the extensive use of antibiotics in aquaculture to treat infections within marine animals has led to the development of multidrug-resistant (MDR) V. parahaemolyticus, which threatens the effectiveness of antimicrobial treatments. Thus, it is vital to explore the alternatives of antibiotics in aquaculture to manage the spread of antibiotic resistance. This study aimed to investigate the prevalence of MDR V. parahaemolyticus to provide insight into the current antibiotic resistance patterns of this pathogen and to determine potential anti-Vibrio properties of Streptomyces MUM 178J which was previously isolated from the soils of a mangrove forest in Sarawak, Malaysia. Colony morphology and toxR-assay indicated that all samples tested positive for V. parahaemolyticus. Further identification with genomic analyses confirmed that 64% (64/100) of the isolates were V. parahaemolyticus. The multiple antibiotic resistance index (MAR) of the isolates ranged between 0.07 and 0.57, with 81% (52/64) of the isolates resistant to more than one antibiotic. The isolates were most resistant to ampicillin (98.4%), followed by ceftazidime (53.1%). In contrast, the isolates were highly susceptible to nalidixic acid (98.4%), tetracycline (93.8%), and sulfamethoxazole/trimethoprim (90.6%). They also demonstrated susceptibilities of 89.1% to levofloxacin, oxytetracycline, and gentamicin. Streptomyces sp. MUM 178J exhibited antagonistic effects on select V. parahaemolyticus strain, RP0132, with a minimum inhibitory concentration of 12.5 mg/mL and a minimum bactericidal concentration of 50 mg/mL.

Advancing Syphilis Research: Exploring New Frontiers in Immunology and Pharmacological Interventions

In recent years, the global resurgence of syphilis has posed significant challenges to public health. This sexually transmitted infection, caused by the bacterium Treponema pallidum, can have severe consequences if left untreated, including neurological and cardiovascular complications. Diagnosing syphilis is complex due to its diverse clinical presentations, necessitating a multifaceted approach, including serological, molecular, and direct techniques such as dark-field microscopy. Penicillin remains the primary and effective treatment, but emerging macrolide-resistant strains have spurred investigations into alternative antibiotics. Syphilis vaccine development faces unique hurdles, yet promising strategies are under investigation. Targeted prevention strategies focus on high-risk populations such as men who have sex with men, pregnant women, and individuals with multiple sexual partners. The integration of syphilis services into primary healthcare enhances accessibility, early detection, and treatment. Innovative point-of-care diagnostics offer rapid, sensitive testing, while ongoing vaccine research holds the potential for long-term prevention. Addressing the global burden of syphilis requires a multifaceted approach, encompassing immunological advancements, innovative diagnostics, targeted prevention, and primary healthcare integration. Collaborative efforts between governments, healthcare systems, researchers, and communities are essential to effectively combat syphilis, striving toward a syphilis-free future that promotes better sexual health and overall well-being.