Bacterial Aggregation in Cerebral Spinal Fluid: The Extent it Occurs and the Clinical Ramifications.

Bacteria can form aggregates in synovial fluid that are resistant to antibiotics, but the ability to form aggregates in cerebral spinal fluid (CSF) is poorly defined. Consequently, the aims of this study were to assess the propensity of four bacterial species to form aggregates in CSF under various conditions. To achieve these aims, bacteria were added to CSF in microwell plates and small flasks at static and different dynamic conditions with the aid of an incubating shaker. The aggregates that formed were assessed for antibiotic resistance and the ability of tissue plasminogen activator (TPA) to disrupt these aggregates and reduce the number of bacteria present when used with antibiotics. The results of this study show that under dynamic conditions all four bacteria species formed aggregates that were resistant to high concentrations of antibiotics. Yet with static conditions, no bacteria formed aggregates and when the CSF volume was increased, only Staphylococcus aureus formed aggregates. Interestingly, the aggregates that formed were easily dispersed by TPA and significant (p < 0.005) decreases in colony-forming units were seen when a combination of TPA and antibiotics were compared to antibiotics alone. These findings have clinical significance in that they show bacterial aggregation does not habitually occur in central nervous system infections, but rather occurs under specific conditions. Furthermore, the use of TPA combined with antibiotics may be advantageous in recalcitrant central nervous system infections and this provides a pathophysiological explanation for an unusual finding in the CLEAR III clinical trial.

Prevalence of the CRISPR-cas system and its association with antibiotic resistance in clinical Klebsiella pneumoniae isolates.

BACKGROUND AND OBJECTIVE(S): CRISPR-Cas is a prokaryotic adaptive immune system that protects bacteria and archaea against mobile genetic elements (MGEs) such as bacteriophages plasmids, and transposons. In this study, we aimed to assess the prevalence of the CRISPR-Cas systems and their association with antibiotic resistance in one of the most challenging bacterial pathogens, Klebsiella pneumoniae. MATERIALS AND METHODS: A total of 105 K. pneumoniae isolates were collected from various clinical infections. Extended-spectrum ß-lactamases (ESBLs) phenotypically were detected and the presence of ESBL, aminoglycoside-modifying enzymes (AME), and CRISPR-Cas system subtype genes were identified using PCR. Moreover, the diversity of the isolates was determined by enterobacterial repetitive intergenic consensus (ERIC)-PCR. RESULTS: Phenotypically, 41.9% (44/105) of the isolates were found to be ESBL producers. A significant inverse correlation existed between the subtype I-E CRISPR-Cas system's presence and ESBL production in K. pneumoniae isolates. Additionally, the frequency of the ESBL genes blaCTX-M1 (3%), blaCTX-M9 (12.1%), blaSHV (51.5%), and blaTEM (33.3%), as well as some AME genes such as aac(3)-Iva (21.2%) and ant(2'')-Ia (3%) was significantly lower in the isolates with the subtype I-E CRISPR-Cas system in comparison to CRISPR-negative isolates. There was a significant inverse correlation between the presence of ESBL and some AME genes with subtype I-E CRISPR-Cas system. CONCLUSION: The presence of the subtype I-E CRISPR-Cas system was correlated with the antibiotic-resistant gene (ARGs). The isolates with subtype I-E CRISPR-Cas system had a lower frequency of ESBL genes and some AME genes than CRISPR-negative isolates.

[Discovery of a New Siderophore Cephalosporin, Cefiderocol].

Cefiderocol is a novel siderophore-conjugated cephalosporin with a catechol residue acting as an iron chelator. Cefiderocol forms a chelating complex with ferric iron and is transported rapidly into bacterial cells through iron-uptake systems. As a result, cefiderocol shows good activity against Gram-negative bacteria, including carbapenem-resistant isolates that are causing significant global health issues. Cefiderocol has been approved for clinical use in the United States and Europe, where it is being used to treat infection caused by carbapenem-resistant Gram-negative pathogens.

Enhanced removal of ciprofloxacin and associated antibiotic-resistant genes from wastewater using a biological aeration filters in combination with Fe3O4-modified zeolite.

Antibiotics release into the water environment through sewage discharge is a significant environmental concern. In the present study, we investigated the removal of ciprofloxacin (CIP) in simulated sewage by biological aeration filter (BAF) equipped with Fe3O4-modified zeolite (Fe3O4@ZF). Fe3O4@ZF were prepared with impregnation method, and the Fe3O4 particles were successfully deposited on the surface of ZF in an amorphous form according to the results of XPS and XRD analysis. The modification also increased the specific surface area (from 16.22 m²/g to 22 m²/g) and pore volume (from 0.0047 cm³/g to 0.0063 cm³/g), improving the adsorption efficiency of antibiotics. Fe3O4 modified ZF improved the treatment performance significantly, and the removal efficiency of CIP in BAF-Fe3O4@ZF was 79%±2.4%. At 10ml/L CIP, the BAF-Fe3O4@ZF reduced the relative abundances of antibiotics resistance genes (ARGs) int, mexA, qnrB and qnrS in the effluent by 57.16%, 39.59%, 60.22%, and 20.25%, respectively, which effectively mitigate the dissemination risk of ARGs. The modification of ZF increased CIP-degrading bacteria abundance, such as Rhizobium and Deinococcus-Thermus, and doubled bacterial ATP activity, promoting CIP degradation. This study offers a viable, efficient method to enhance antibiotic treatment and prevent leakage via sewage discharge.

Vaccines designed to reduce antimicrobial resistance.

Attention is beginning to focus on the need for vaccines to tackle antimicrobial resistant pathogens. Gary Humphreys reports.

Impact of the COVID-19 pandemic on Haemophilus influenzae infections in pediatric patients hospitalized with community acquired pneumonia.

The COVID-19 pandemic has altered the infection landscape for many pathogens. This retrospective study aimed to compare Haemophilus influenzae (H. influenzae) infections in pediatric CAP patients hospitalized before (2018-2019) and during (2020-2022) the COVID-19 pandemic. We analyzed the clinical epidemiology and antimicrobial resistance (AMR) patterns of H. influenzae from a tertiary hospital in southwest China. A total of 986 pediatric CAP patients with H. influenzae-associated infections were included. Compared to 2018, the positivity rate increased in 2019 but dropped significantly in 2020. Although it rose in the following 2 years, the rate in 2022 remained significantly lower than in 2019. Patients' age during the pandemic was significantly higher than in 2018 and 2019, while gender composition remained similar across both periods. Notably, there were significant changes in co-infections with several respiratory pathogens during the pandemic. Resistance rates of H. influenzae isolates to antibiotics varied, with the highest resistance observed for ampicillin (85.9%) and the lowest for cefotaxime (0.0%). Resistance profiles to various antibiotics underwent dramatic changes during the COVID-19 pandemic. Resistance to amoxicillin-clavulanate, cefaclor, cefuroxime, trimethoprim-sulfamethoxazole, and the proportion of multi-drug resistant (MDR) isolates significantly decreased. Additionally, MDR isolates, alongside isolates resistant to specific drugs, were notably prevalent in ampicillin-resistant and ß-lactamase-positive isolates. The number of pediatric CAP patients, H. influenzae infections, and isolates resistant to certain antibiotics exhibited seasonal patterns, peaking in the winter of 2018 and 2019. During the COVID-19 pandemic, sharp decreases were observed in February 2020, and there was no resurgence in December 2022. These findings indicate that the COVID-19 pandemic has significantly altered the infection spectrum of H. influenzae in pediatric CAP patients, as evidenced by shifts in positivity rate, demographic characteristics, respiratory co-infections, AMR patterns, and seasonal trends.

How to Mitigate Community Harms of Antibacterial Resistance With Patient-Centered Care.

Overprescription of antibiotics in cases in which bacterial infection is clinically uncertain contributes to increased prevalence of multidrug-resistant bacteria. Ethically, merits and drawbacks of stricter prescription practice oversight should be weighed against risks of untreatable bacterial infections to patients and communities. This article considers how to balance this set of ideas and values.

How Should Focus Be Shifted From Individual Preference to Collective Wisdom for Patients at the End of Life With Antimicrobial-Resistant Infections?

Despite growth in numbers of organizational antimicrobial stewardship programs, antimicrobial resistance continues to escalate. Interprofessional education and collaboration are needed to make these programs appropriately responsive to the ethically and clinically complex needs of patients at the end of life whose care plans still require antimicrobial management.

Antimicrobial resistance and genome characteristics of Salmonella enteritidis from Huzhou, China.

Salmonella enteritidis is a main pathogen responsible for sporadic outbreaks of gastroenteritis, and therefore is an important public health problem. This study investigated the drug resistance and genomic characteristics of S. enteritidis isolated from clinical and food sources in Huzhou, Zhejiang Province, China, from February 1, 2021, to December 30, 2023. In total, 43 S. enteritidis strains isolated during the study period were subjected to virulence gene, drug resistance gene, genetic correlation, antibiotic resistance, and multilocus sequence typing analyses. All 43 isolates were identified as ST11, and contained 108 virulence-related genes. Drug sensitivity analysis of the 43 isolates showed resistance rates of 100% to nalidixic acid and 90.70% to ampicillin and ampicillin/sulbactam. Multidrug resistance is a serious issue, with 81.40% of strains resistant to three or more antibacterial drugs. Genome sequencing indicated that S. enteritidis possessed 23 drug resistance genes, of which 14 were common to all 43 isolates. Phylogenetic analysis based on core genome single-nucleotide polymorphisms divided the 43 S. enteritidis strains into three clusters, with the 10 samples from an outbreak forming an independent branch located in cluster 3.

Topical Clindamycin in the Management of Acne Vulgaris: Current Perspectives and Recent Therapeutic Advances.

Clindamycin is a lincosamide-derivate antibiotic that has been widely used both systemically and topically for approximately 5 decades. The antimicrobial profile of clindamycin primarily covers several gram-positive bacteria and anaerobic bacteria, with multiple clinical applications supported in the literature and with widespread real-world use. Topical clindamycin has been used primarily for the treatment of acne vulgaris, with both monotherapy and combination therapy formulations available commercially. This article reviews the use of clindamycin as a topical agent with emphasis on therapy for acne vulgaris, and addresses modes of action, reported anti-inflammatory properties that may relate to therapeutic outcomes, recommendations to avoid the emergence of antibiotic-resistant bacteria, tolerability and safety considerations, and published data from clinical studies completed over a span of several years. A discussion of a newly FDA-approved triple-combination formulation is also included.  J Drugs Dermatol. 2024;23(6):438-445.     doi:10.36849/JDD.8318.

Whole genome sequencing analysis on antibiotic-resistant Escherichia coli isolated from pig farms in Banten Province, Indonesia.

IMPORTANCE: The emergence and rapid increase in the incidence of multidrug-resistant (MDR) bacteria in pig farms has become a serious concern and reduced the choice of effective antibiotics. OBJECTIVE: This study analyzed the phylogenetics and diversity of antibiotic resistance genes (ARGs) and molecularly identified the source of ARGs in antibiotic-resistant Escherichia coli isolated from pig farms in Banten Province, Indonesia. METHODS: Forty-four antibiotic-resistant E. coli isolates from fecal samples from 44 pig farms in Banten Province, Indonesia, were used as samples. The samples were categorized into 14 clusters. Sequencing was performed using the Oxford Nanopore Technologies MinION platform, with barcoding before sequencing with Nanopore Rapid sequencing gDNA-barcoding (SQK-RBK110.96) according to manufacturing procedures. ARG detection was conducted using ResFinder, and the plasmid replicon was determined using PlasmidFinder. RESULTS: Three phylogenetic leaves of E. coli were identified in the pig farming cluster in Banten Province. The E. coli isolates exhibited potential resistance to nine classes of antibiotics. Fifty-one ARGs were identified across all isolates, with each cluster carrying a minimum of 10 ARGs. The ant(3'')-Ia and qnrS1 genes were present in all isolates. ARGs in the E. coli pig farming cluster originated mainly from plasmids, accounting for an average of 89.4%. CONCLUSIONS AND RELEVANCE: The elevated potential for MDR events, coupled with the dominance of ARGs originating from plasmids, increases the risk of ARG spread among bacterial populations in animals, humans, and the environment.

Cost-effectiveness of resistance-guided therapy for Mycoplasma genitalium in Australia.

The recommended first-line treatment for Mycoplasma genitalium infections is azithromycin. However, the prevalence of macrolide resistance for M. genitalium has increased to more than 50% worldwide. In 2013, Australia introduced a resistance-guided therapy (RGT) strategy to manage M. genitalium infections. This study assesses the cost-effectiveness of the RGT approach compared to no RGT (i.e., without macrolide resistance profile test) in women, men who have sex with men (MSM), and men who have sex with women (MSW) in Australia. We constructed dynamic transmission models of M. genitalium infections in women, MSM, and MSW in Australia, each with a population of 100,000. These models compared the costs and quality-adjusted life-years (QALYs) gained between RGT and no RGT scenarios from a healthcare perspective over ten years. All costs are reported in 2022 Australian dollars (Australian $). In our model, RGT is cost saving in women and MSM, with the incremental net monetary benefit of $1.3 million and $17.9 million, respectively. In MSW, the RGT approach is not cost-effective, with an incremental cost-effectiveness ratio of -$106.96 per QALY gained. RGT is cost saving compared to no RGT for M. genitalium infections in women and MSM, supporting its adoption as the national management strategy for these two population groups.

Evaluation the kill rate and mutant selection window of danofloxacin against Actinobacillus pleuropneumoniae in a peristaltic pump model.

BACKGROUND: Actinobacillus pleuropneumoniae is a serious pathogen in pigs. The abundant application of antibiotics has resulted in the gradual emergence of drugresistant bacteria, which has seriously affected treatment of disease. To aid measures to prevent the emergence and spread of drug-resistant bacteria, herein, the kill rate and mutant selection window (MSW) of danofloxacin (DAN) against A. pleuropneumoniae were evaluated. METHODS: For the kill rate study, the minimum inhibitory concentration (MIC) was tested using the micro dilution broth method and time-killing curves of DAN against A. pleuropneumoniae grown in tryptic soy broth (TSB) at a series drug concentrations (from 0 to 64 MIC) were constructed. The relationships between the kill rate and drug concentrations were analyzed using a Sigmoid Emax model during different time periods. For the MSW study, the MIC99 (the lowest concentration that inhibited the growth of the bacteria by ≥ 99%) and mutant prevention concentration (MPC) of DAN against A. pleuropneumoniae were measured using the agar plate method. Then, a peristaltic pump infection model was established to simulate the dynamic changes of DAN concentrations in pig lungs. The changes in number and sensitivity of A. pleuropneumoniae were measured. The relationships between pharmacokinetic/pharmacodynamic parameters and the antibacterial effect were analyzed using the Sigmoid Emax model. RESULTS: In kill rate study, the MIC of DAN against A. pleuropneumoniae was 0.016 µg/mL. According to the kill rate, DAN exhibited concentration-dependent antibacterial activity against A. pleuropneumoniae. A bactericidal effect was observed when the DAN concentration reached 4-8 MIC. The kill rate increased constantly with the increase in DAN concentration, with a maximum value of 3.23 Log10 colony forming units (CFU)/mL/h during the 0-1 h period. When the drug concentration was in the middle part of the MSW, drugresistant bacteria might be induced. Therefore, the dosage should be avoided to produce a mean value of AUC24h/MIC99 (between 31.29 and 62.59 h. The values of AUC24h/MIC99 to achieve bacteriostatic, bactericidal, and eradication effects were 9.46, 25.14, and > 62.59 h, respectively. CONCLUSION: These kill rate and MSW results will provide valuable guidance for the use of DAN to treat A. pleuropneumoniae infections.

Molecular Prevalence and Geographical Variations of Carbapenem-Resistant Klebsiella pneumoniae ST15 Isolates in a Tertiary Hospital in Ningbo, China.

BACKGROUND In China, the most prevalent type of CRKP is ST11, but the high-risk clone ST15 has grown in popularity in recent years, posing a serious public health risk. Therefore, we investigated the molecular prevalence characteristics of ST15 CRKP detected in a tertiary hospital in Ningbo to understand the current potential regional risk of ST15 CRKP outbreak. MATERIAL AND METHODS We collected and evaluated 18 non-duplicated CRKP strains of ST15 type for antibiotic resistance. Their integrons, virulence genes, and resistance genes were identified using polymerase chain reaction (PCR), and their homology was determined using MALDI-TOF MS. RESULTS The predominant serotype of 18 ST15 CRKP strains was K5. ST15 CRKP exhibited the lowest antimicrobial resistance to Cefoperazone/sulbactam (11.1%), followed by trimethoprim/sulfamethoxazole (22.2%). Resistance gene testing revealed that 14 out of 18 ST15 CRKP strains (77.8%) carried Klebsiella pneumoniae carbapenemase 2 (KPC-2), whereas all ST15 CRKP integrons were of the intI1 type. Furthermore, virulence gene testing revealed that all 18 ST15 CRKP strains carried ybtS, kfu, irp-1, and fyuA genes, followed by the irp-2 gene (17 strains) and entB (16 strains). The homology analysis report showed that 2 clusters had closer affinity, which was mainly concentrated in classes C and D. CONCLUSIONS The ST15 CRKP antibiotic resistance rates demonstrate clear geographical differences in Ningbo. Additionally, some strains carried highly virulent genes, indicating a possible evolution towards carbapenem-resistant highly virulent strains. To reduce the spread of ST15 CRKP, we must rationalize the clinical use of antibiotics and strengthen resistance monitoring to control nosocomial infections.

Mechanisms of Triton X-100 reducing the Ag+-resistance of Enterococcus faecalis.

To investigate the mechanism of Triton X-100 (TX-100) reducing the Ag+-resistance of Enterococcus faecalis (E. faecalis), and evaluate the antibacterial effect of TX-100 + Ag+ against the induced Ag+-resistant E. faecalis (AREf). The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of AgNO3 against E. faecalis with/without TX-100 were determined to verify the enhanced antibacterial activity. Transmission electron microscopy (TEM) was used to observe the morphological changes of E. faecalis after treatment. The intra- and extracellular concentration of Ag+ in treated E. faecalis was evaluated using inductively coupled plasma mass spectrometer (ICP-MS). The changes in cell membrane potential and integrity of treated E. faecalis were also observed using the flow cytometer. Moreover, AREf was induced through continuous exposure to sub-MIC of Ag+ and the antibacterial effect of TX-100 + Ag+ on AREf was further evaluated. The addition of 0.04% TX-100 showed maximal enhanced antibacterial effect of Ag+ against E. faecalis. The TEM and ICP-MS results demonstrated that TX-100 could facilitate Ag+ to enter E. faecalis through changing the membrane structure and integrity. Flow cytometry further showed the effect of TX-100 on membrane potential and permeability of E. faecalis. In addition, the enhanced antibacterial effect of TX-100 + Ag+ was also confirmed on induced AREf. TX-100 can facilitate Ag+ to enter E. faecalis through disrupting the membrane structure and changing the membrane potential and permeability, thus reducing the Ag+-resistance of E. faecalis and enhancing the antibacterial effect against either normal E. faecalis or induced AREf.

Effect of erythromycin residuals in food on the development of resistance in Streptococcus pneumoniae: an in vivo study in Galleria mellonella.

Background: The use of antimicrobials to treat food animals may result in antimicrobial residues in foodstuffs of animal origin. The European Medicines Association (EMA) and World Health Organization (WHO) define safe antimicrobial concentrations in food based on acceptable daily intakes (ADIs). It is unknown if ADI doses of antimicrobials in food could influence the antimicrobial susceptibility of human-associated bacteria. Objectives: This aim of this study was to evaluate if the consumption of ADI doses of erythromycin could select for erythromycin resistance in a Galleria mellonella model of Streptococcus pneumoniae infection. Methods: A chronic model of S. pneumoniae infection in G. mellonella larvae was used for the experiment. Inoculation of larvae with S. pneumoniae was followed by injections of erythromycin ADI doses (0.0875 and 0.012 µg/ml according to EMA and WHO, respectively). Isolation of S. pneumoniae colonies was then performed on selective agar plates. Minimum inhibitory concentrations (MICs) of resistant colonies were measured, and whole genome sequencing (WGS) was performed followed by variant calling to determine the genetic modifications. Results: Exposure to single doses of both EMA and WHO ADI doses of erythromycin resulted in the emergence of erythromycin resistance in S. pneumoniae. Emergent resistance to erythromycin was associated with a mutation in rplA, which codes for the L1 ribosomal protein and has been linked to macrolide resistance in previous studies. Conclusion: In our in vivo model, even single doses of erythromycin that are classified as acceptable by the WHO and EMA induced significant increases in erythromycin MICs in S. pneumoniae. These results suggest the need to include the induction of antimicrobial resistance (AMR) as a significant criterion for determining ADIs.

Mind the gap: knowledge, attitudes and perceptions on antimicrobial resistance, antimicrobial stewardship and infection prevention and control in long-term care facilities for people with disabilities in the Netherlands.

BACKGROUND: Antimicrobial resistance (AMR) has become one of the major public health threats worldwide, emphasizing the necessity of preventing the development and transmission of drug resistant microorganisms. This is particularly important for people with vulnerable health conditions, such as people with intellectual disabilities (ID) and long-term care residents. This study aimed to assess the current status of AMR, antimicrobial stewardship (AMS) and infection prevention and control (IPC) in Dutch long-term care facilities for people with intellectual disabilities (ID-LTCFs). METHODS: A web-based cross-sectional survey distributed between July and November 2023, targeting (both nonmedically and medically trained) healthcare professionals working in ID-LTCFs in The Netherlands, to study knowledge, attitudes and perceptions regarding AMR, AMS and IPC. RESULTS: In total, 109 participants working in 37 long-term care organizations for people with intellectual disabilities throughout the Netherlands completed the questionnaire. The knowledge levels of AMR and IPC among nonmedically trained professionals (e.g., social care professionals) were lower than those among medically trained professionals (p = 0.026). In particular regarding the perceived protective value of glove use, insufficient knowledge levels were found. Furthermore, there was a lack of easy-read resources and useful information regarding IPC and AMR, for both healthcare professionals as well as people with disabilities. The majority of the participants (> 90%) reported that AMR and IPC need more attention within the disability care sector, but paradoxically, only 38.5% mentioned that they would like to receive additional information and training about IPC, and 72.5% would like to receive additional information and training about AMR. CONCLUSION: Although the importance of AMR and IPC is acknowledged by professionals working in ID-LTCFs, there is room for improvement in regards to appropriate glove use and setting-specific IPC and hygiene policies. As nonmedically trained professionals comprise most of the workforce within ID-LTCFs, it is also important to evaluate their needs. This can have a substantial impact on developing and implementing AMR, AMS and/or IPC guidelines and policies in ID-LTCFs.

Prevalence and antimicrobial susceptibility of Salmonella enteritidis and Salmonella typhimurium isolated from hen eggs and quail eggs in Karaj, Iran.

BACKGROUND AND AIM: Different Salmonella serotypes are considered one of the most important food pathogens in the world. Poultry meat and eggs are the primary carriers of Salmonella in human populations. This study aimed to estimate the Salmonella enteritidis and Salmonella typhimurium contamination rates of retail hen and quail eggs in Karaj, Iran. Moreover, the antimicrobial resistance patterns of the strains were evaluated, and the efficiency of the standard culture method and multiplex polymerase chain reaction (m-PCR) were compared. MATERIALS AND METHODS: In this descriptive cross-sectional study over 1 year (Jan-Dec 2022), 150 commercial and 150 backyard hen eggs and 300 commercial quail eggs, without cracks and fractures, were collected randomly from best selling groceries in Karaj city. All samples were examined for Salmonella contamination independently by standard culture and m-PCR approaches. A standard disc diffusion method was employed to assess the antimicrobial susceptibility of the strains against 18 antimicrobial agents. RESULTS: Out of 300 examined eggs, 2 S. enteritidis strains were isolated from the shell of backyard hen eggs. The same serotype was also detected in the contents of one of these two eggs. One S. typhimurium was isolated from the shell of a commercial hen egg. Overall, the Salmonella contamination of the shell and contents was 1% and 0.3%, respectively. Salmonella was not isolated from the eggshells or the contents of the quail eggs. There was complete agreement between the results of m-PCR and the standard culture methods. Among the 18 tested antibiotics, the highest resistance was recorded for colistin (100%), followed by nalidixic acid (75%). CONCLUSION: As most Salmonella spp. are associated with human food poisoning, continuous surveillance is required to effectively reduce the risk posed by contaminated poultry eggs. Furthermore, mandatory monitoring of antimicrobial use on Iranian poultry farms is recommended.

Integrative and Conjugative Elements and Prophage DNA as Carriers of Resistance Genes in Erysipelothrix rhusiopathiae Strains from Domestic Geese in Poland.

Goose erysipelas is a serious problem in waterfowl breeding in Poland. However, knowledge of the characteristics of Erysipelothrix rhusiopathiae strains causing this disease is limited. In this study, the antimicrobial susceptibility and serotypes of four E. rhusiopathiae strains from domestic geese were determined, and their whole-genome sequences (WGSs) were analyzed to detect resistance genes, integrative and conjugative elements (ICEs), and prophage DNA. Sequence type and the presence of resistance genes and transposons were compared with 363 publicly available E. rhusiopathiae strains, as well as 13 strains of other Erysipelothrix species. Four strains tested represented serotypes 2 and 5 and the MLST groups ST 4, 32, 242, and 243. Their assembled circular genomes ranged from 1.8 to 1.9 kb with a GC content of 36-37%; a small plasmid was detected in strain 1023. Strains 1023 and 267 were multidrug-resistant. The resistance genes detected in the genome of strain 1023 were erm47, tetM, and lsaE-lnuB-ant(6)-Ia-spw cluster, while strain 267 contained the tetM and ermB genes. Mutations in the gyrA gene were detected in both strains. The tetM gene was embedded in a Tn916-like transposon, which in strain 1023, together with the other resistance genes, was located on a large integrative and conjugative-like element of 130 kb designated as ICEEr1023. A minor integrative element of 74 kb was identified in strain 1012 (ICEEr1012). This work contributes to knowledge about the characteristics of E. rhusiopathiae bacteria and, for the first time, reveals the occurrence of erm47 and ermB resistance genes in strains of this species. Phage infection appears to be responsible for the introduction of the ermB gene into the genome of strain 267, while ICEs most likely play a key role in the spread of the other resistance genes identified in E. rhusiopathiae.