Porphyromonas spp. are oral anaerobes that play a key role in the pathogenesis of canine periodontal disease. Despite their clinical relevance in veterinary medicine, data on the antimicrobial susceptibility of canine Porphyromonas isolates remain limited. Therefore, we assessed the antimicrobial susceptibility of Porphyromonas spp. isolated from the subgingival plaque of dogs with periodontitis in South Korea. Fifty-eight dogs diagnosed with periodontal disease were screened for Porphyromonas spp., and species identification was confirmed using PCR and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Antimicrobial susceptibility testing was performed using the broth microdilution method with the Sensititre AN02B panel. Overall, 40 isolates were recovered from 30 of the 58 dogs sampled, comprising 15 Porphyromonas gulae, 11 Porphyromonas macacae, eight Porphyromonas gingivalis, five Porphyromonas gingivicanis, and one Porphyromonas crevioricanis. Resistance was detected in six isolates (15%) to penicillin, three (7.5%) to imipenem, three (7.5%) to meropenem, 15 (25%) to clindamycin, and seven (17.5%) to ampicillin. No resistance was observed to ampicillin/sulbactam, amoxicillin/clavulanic acid, cefotetan, cefoxitin, metronidazole, chloramphenicol, piperacillin, tetracycline, mezlocillin, or piperacillin/tazobactam. These findings provide crucial insights into the antimicrobial susceptibility patterns of canine oral Porphyromonas spp. and highlight the importance of judicious antimicrobial use in veterinary dentistry.

Benzalkonium chloride (BAC) has been widely used as disinfectant in food processing, whereas there is still largely unknown concerning its profound and/or reverse effects on the pathogens control. This study was aimed to assess the effects of BAC disinfection on the controlling difficulty of foodborne pathogens, by investigating the growth rate, micromorphology, biofilm characteristics, and antibiotic resistance. The results showed that two pathogenic strains, identified as Proteus vulgaris PV29 and Bacillus cereus BC30, were residually remained on the processing utensils after BAC disinfection. Moreover, compared with the parent cells, the micromorphology of the subcutured cells under BAC stress changed, while final cell densities of P. vulgaris PV29 and B. cereus BC30 increased by 106 % and 18 %, respectively. In addition, the BAC-adapted cells formed more obvious and denser biofilms, within which the cell density doubled at most. Even worse, antibiotic resistance of the both strains to common antibiotics (including vancomycin, sulfamethoxazole, mezlocillin sodium, and minocycline) increased after prolonged BAC-adaption. In sum, the present study verified increased difficulty to control the foodborne pathogens of P. vulgaris PV29 and B. cereus BC30 with regular BAC disinfection, and enlighten future assessment on the potential risks of BAC disinfection.

Immunoglobulin E (IgE)-mediated immediate hypersensitivity reactions are the most concerning adverse events after penicillin antibiotics (PENs) administration because of their rapid progression and potential for fatal outcome. However, the diagnosis of allergic death is a forensic challenge because it mainly depends on nonspecific characteristic morphological changes, as well as exclusion and circumstantial evidence. In this study, an untargeted metabolomics approach based on liquid chromatography-mass spectrometry (LC-MS) was used to screen potential forensic biomarkers of fatal anaphylactic shock induced by four PENs (benzylpenicillin (BP), amoxicillin (AMX), oxacillin (OXA), and mezlocillin (MEZ)), and analyzed the metabolites, metabolic pathway and the mechanism which were closely related to the allergic reactions. The metabolomics results discovered that a total of 24 different metabolites in all four anaphylactic death (AD) groups, seven of which were common metabolites. A biomarker model consisting of six common metabolites (linoleic acid, prostaglandin D2, lysophosphatidylcholine (18:0), N-acetylhistamine, citric acid and indolelactic acid) AUC value of Receiver Operating Characteristic (ROC) curve was 0.978. Metabolism pathway analysis revealed that the pathogenesis of PENs-induced AD is closely related to linoleic acid metabolism. Our results revealed that the metabolomic profiling has potential in PENs-induced AD post-mortem diagnosis and metabolic mechanism investigations.

Salmonella spp. pose a global threat as a leading cause of foodborne illnesses, particularly prevalent in the European Union (EU), where it remains the second cause of foodborne outbreaks. The emergence of antimicrobial resistance (AMR) in Salmonella spp. has become a critical concern, complicating treatment strategies and escalating the risk of severe infections. The study focuses on large and small ruminants, identifying a prevalence of Salmonella spp. in slaughterhouses and revealing varied AMR rates across antimicrobial families throughout a meta-analysis. Also, comparison with AMR in human medicine was carried out by a systematic review. The results of the present meta-analysis displayed a prevalence of Salmonella spp. in large and small ruminants at slaughterhouses of 8.01% (8.31%, cattle; 7.04%, goats; 6.12%, sheep). According to the AMR of Salmonella spp., 20, 14, and 13 out of 62 antimicrobials studied were classified as low (<5%), high (>5% but <10%), and very high (>10%), respectively. Salmonella spp. did not display AMR against aztreonam, mezlocillin, ertapenem, meropenem, cefoxitin, ceftazidime, levofloxacin, tilmicosin, linezolid, fosfomycin, furazolidone, quinupristin, trimethoprim and spectinomycin. In contrast, a prevalence of 100% of AMR has been described against ofloxacin, lincomycin, and cloxacillin. In the context of the main antibiotics used in the treatment of human salmonellosis, azithromycin was shown to have the highest resistance among Salmonella spp. isolates from humans. Regarding cephalosporins, which are also used for the treatment of salmonellosis in humans, the prevalence of Salmonella spp. resistance to this class of antibiotics was similar in both human and animal samples. Concerning quinolones, despite a heightened resistance profile in Salmonella spp. isolates from ruminant samples, there appears to be no discernible compromise to the efficacy of salmonellosis treatment in humans since lower prevalences of AMR in Salmonella spp. isolated from human specimens were observed. Although the resistance of Salmonella spp. indicates some degree of concern, most antibiotics are not used in veterinary medicine. Thus, the contribution of cattle, sheep and goats to the rise of antibiotic resistance of Salmonella spp. and its potential impact on public health appears to be relatively insignificant, due to their low prevalence in carcasses and organs. Nevertheless, the observed low prevalence of Salmonella spp. in ruminants at slaughterhouse and the correspondingly low AMR rates of Salmonella spp. to key antibiotics employed in human medicine do not indicate that ruminant livestock poses a substantial public health risk concerning the transmission of AMR. Thus, the results observed in both the meta-analysis and systematic review suggests that AMR is not solely attributed to veterinary antibiotic use but is also influenced by factors such as animal health management (i.e., biosecurity measures, prophylactic schemes) and human medicine.

Effective treatment of gonorrhea is threatened by the increasing prevalence of Neisseria gonorrhoeae strains resistant to the extended-spectrum cephalosporins (ESCs). Recently, we demonstrated the promise of the third-generation cephalosporin cefoperazone as an antigonococcal agent due to its rapid second-order rate of acylation against penicillin-binding protein 2 (PBP2) from the ESC-resistant strain H041 and robust antimicrobial activity against H041. Noting the presence of a ureido moiety in cefoperazone, we evaluated a subset of structurally similar ureido β-lactams, including piperacillin, azlocillin, and mezlocillin, for activity against PBP2 from H041 using biochemical and structural analyses. We found that the ureidopenicillin piperacillin has a second-order rate of acylation against PBP2 that is 12-fold higher than cefoperazone and 85-fold higher than ceftriaxone and a lower MIC against H041 than ceftriaxone. Surprisingly, the affinity of ureidopenicillins for PBP2 is minimal, indicating that their inhibitory potency is due to a higher rate of the acylation step of the reaction compared to cephalosporins. Enhanced acylation results from the combination of a penam scaffold with a 2,3-dioxopiperazine-containing R1 group. Crystal structures show that the ureido β-lactams overcome the effects of resistance mutations present in PBP2 from H041 by eliciting conformational changes that are hindered when PBP2 interacts with the weaker inhibitor ceftriaxone. Overall, our results support the potential of piperacillin as a treatment for gonorrhea and provide a framework for the future design of β-lactams with improved activity against ESC-resistant N. gonorrhoeae.

Antibiotics are widely used for prophylaxis and therapy, reducing morbidity and mortality produced by bacterial pathogensin pigs, including infections caused by Escherichia coli. The aim of this study was to characterise antibiotic resistance phenotypes and genotypes in E. coli isolates in pigs in West Romanian grower farms. Differential phenotypic susceptibility profiles and the contribution of resistance genes to phenotypic expression of susceptibility or resistance were evaluated. A total of 76 E. coli isolates were identified and confirmed by the MicroScan Walk Away System. The occurrence of four resistance genes, ampC, blaZ, blaTEM and tetK in strains resistant to 13 antibiotics was assessed. Of the E. coli isolates, 0% showed resistance to meropenem, 3.9% to tigecycline and 10.5% to piperacillin/tazobactam, whereas, in contrast, 100% were resistant to ampicillin and mezlocillin, 76.31% to piperacillin and 59.3% to tetracycline. The prevalence of resistance genes in resistant isolates detected by q-PCR analysis was 97.0% for ampC, 96% for blaZ, 32.9% for blaTEM and 58.8% for tetK. Penetrance (the proportion of individuals carrying a particular variant of a gene that also expresses an associated trait) was 50% for ampC (32% for amoxicillin/clavulanate, 62% for cefazolin, 32% for cefepime, 100% for cefotaxime, 56% for cefuroxime and 99% for ampicillin), 65% for blaZ (32% for amoxicillin/clavulanate and 99% for ampicillin), 51% for blaTEM (81% for piperacillin) and 44% for the tetK gene (83% for tetracycline). The result of phenotypic antibiotic resistance testing may indicate the presence of plasmid-borne resistance, with a diagnostic odds ratio of a positive phenotypic resistance for tetK being 4.52. As a management decision, the maximum penetrance admitted for using a specific antibiotic for E. coli infections in pigs is recommended to be less than 20%.

Objective: Acute kidney injury (AKI) is a common adverse reaction observed with the clinical use of cefoperazone-sulbactam sodium and mezlocillin-sulbactam sodium. Based upon real-world data, we will herein determine the risk factors associated with AKI in inpatients after receipt of these antimicrobial drugs, and we will develop predictive models to assess the risk of AKI. Methods: Data from all adult inpatients who used cefoperazone-sulbactam sodium and mezlocillin-sulbactam sodium at the First Affiliated Hospital of Shandong First Medical University between January 2018 and December 2020 were analyzed retrospectively. The data were collected through the inpatient electronic medical record (EMR) system and included general information, clinical diagnosis, and underlying diseases, and logistic regression was exploited to develop predictive models for the risk of AKI. The training of the model strictly adopted 10-fold cross-validation to validate its accuracy, and model performance was evaluated employing receiver operating characteristic (ROC) curves and the areas under the curve (AUCs). Results: This retrospective study comprised a total of 8767 patients using cefoperazone-sulbactam sodium, of whom 1116 developed AKI after using the drug, for an incidence of 12.73%. A total of 2887 individuals used mezlocillin-sulbactam sodium, of whom 265 developed AKI after receiving the drug, for an incidence of 9.18%. In the cohort administered cefoperazone-sulbactam sodium, 20 predictive factors (p < 0.05) were applied in constructing our logistic predictive model, and the AUC of the predictive model was 0.83 (95% CI, 0.82-0.84). In the cohort comprising mezlocillin-sulbactam sodium use, nine predictive factors were determined by multivariate analysis (p < 0.05), and the AUC of the predictive model was 0.74 (95% CI, 0.71-0.77). Conclusion: The incidence of AKI induced by cefoperazone-sulbactam sodium and mezlocillin-sulbactam sodium in hospitalized patients may be related to the combined treatment of multiple nephrotoxic drugs and a past history of chronic kidney disease. The AKI-predictive model based on logistic regression showed favorable performance in predicting the AKI of adult in patients who received cefoperazone-sulbactam sodium or mezlocillin-sulbactam sodium.

It has been revealed that the administration of an antimicrobial prophylaxis (AP) reduces the rate of surgical site (SSI) following colorectal cancer surgery. Nevertheless, the optimal timing of this medication remains unclear. The aim of this study was to determine more precisely the optimal time for administering antibiotics and to see if this could reduce the number of possible surgical site infections. The files of individuals who underwent colorectal cancer surgery at the University Hospital Brandenburg an der Havel (Germany) between 2009 and 2017 were analyzed. Piperacillin/tazobactam, cefuroxime/metronidazole and mezlocillin/sulbactam were administered as AP regimens. Timing of AP was obtained. The primary objective was the rate of SSIs based on CDC criteria. Multivariate analysis took place to identify risk factors for SSIs. A total of 326 patients (61.4%) received an AP within 30 min, 166 (31.3%) between 30 and 60 min, 22 (4.1%) more than 1 h before surgery, and 15 (2.8%) after surgery. In 19 cases (3.6%) a SSI occurred during hospital stay. A multivariate analysis did not identify AP timing as a risk factor for the occurrence of SSIs. With significance, more surgical site occurrences (SSO) were diagnosed when cefuroxime/metronidazole was given. Our results suggest that AP with cefuroxime/metronidazole is less effective in reducing SSO compared with mezlocillin/sulbactam and tazobactam/piperacillin. We assume that the timing of this AP regimen of < 30 min or 30-60 min prior to colorectal surgery does not impact the SSI rate.

In this study, we collected feces of Tibetan piglets from Nyingchi area for isolation, culture, identification, virulence gene analysis and drug resistance analysis of Escherichia Coli. The results demonstrated a 41.3% isolation rate of Diarrheagenic Escherichia Coli from Tibetan pigs with the main phylogenetic groups: group A (68.6%) and group B2 (15.7%). Typical E.coli accounted for 76.5%. The highest detection rates of porcine virulence genes were E.coli heat-resistant enterotoxin STb (58.82%) and F107 fimbrial subunit (23.53%). The highest detection rates of virulence genes from Tibetan pigs were fimC (80.39%) and ompA (76.47%). A drug sensitivity test showed that Diarrheagenic Escherichia Coli from Tibetan pigs had high drug resistance rates to mezlocillin, doxycycline and gentamicin. This study comprehensively analyzed the species composition, virulence and drug resistance of Diarrheagenic Escherichia Coli from Tibetan pigs, which provided a clearer and more targeted idea for the prevention and treatment of yellow and white dysentery in Tibetan pigs in the future.