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Antibiotics, Volume 12; https://doi.org/10.3390/antibiotics12061026
According to the Food and Agriculture Organization of the United Nations, pork remains the most consumed meat in the world. Consequently, it is very important to ensure that it is of the highest microbiological quality. Many of the pathogens that cause lymph node lesions in pigs are zoonotic agents, and the most commonly isolated bacteria are Mycobacterium spp., Streptococcus spp., Staphylococcus aureus and Rhodococcus equi (synonymous with Prescottella equi). The prevention and treatment of zoonotic infections caused by these bacteria are mainly based on antimicrobials. However, an overuse of antimicrobials contributes to the emergence and high prevalence of antimicrobial-resistant strains, which are becoming a serious challenge in many countries. The aim of this study was to evaluate the genetic diversity and antimicrobial resistance of the Streptococcus spp. (n = 48), S. aureus (n = 5) and R. equi (n = 17) strains isolated from swine lymph nodes with and without lesions. All isolates of S. dysgalactiae, S. aureus and R. equi were subjected to PFGE analysis, which showed the genetic relatedness of the tested bacteria in the studied pig populations. Additionally, selected tetracycline and macrolide resistance genes in the streptococcal strains were also studied. The results obtained in the present study provide valuable data on the prevalence, diversity, and antimicrobial resistance of the studied bacteria. Numerous isolated bacterial Streptococcus spp. strains presented resistance to doxycycline, and almost half of them carried tetracycline resistance genes. In addition, R. equi and S. aureus bacteria presented a high level of resistance to beta-lactam antibiotics and to cefotaxime, respectively.
Antibiotics, Volume 12; https://doi.org/10.3390/antibiotics12061025
Copious use of antibiotics in aquaculture farming systems has resulted in surface water contamination in some countries. Our objective was to develop a slow-release oxidant that could be used in situ to reduce antibiotic concentrations in discharges from aquaculture lagoons. We accomplished this by generating a slow-release permanganate (SR-MnO4−) that was composed of a biodegradable wax and a phosphate-based dispersing agent. Sulfadimethoxine (SDM) and its synergistic antibiotics were used as representative surrogates. Kinetic experiments verified that the antibiotic-MnO4− reactions were first-order with respect to MnO4− and initial antibiotic concentration (second-order rates: 0.056–0.128 s−1 M−1). A series of batch experiments showed that solution pH, water matrices, and humic acids impacted SDM degradation efficiency. Degradation plateaus were observed in the presence of humic acids (>20 mgL−1), which caused greater MnO2 production. A mixture of KMnO4/beeswax/paraffin (SRB) at a ratio of 11.5:4:1 (w/w) was better for biodegradability and the continual release of MnO4−, but MnO2 formation altered release patterns. Adding tetrapotassium pyrophosphate (TKPP) into the composite resulted in delaying MnO2 aggregation and increased SDM removal efficiency to 90% due to the increased oxidative sites on the MnO2 particle surface. The MnO4− release data fit the Siepmann–Peppas model over the long term (t < 48 d) while a Higuchi model provided a better fit for shorter timeframes (t < 8 d). Our flow-through discharge tank system using SRB with TKPP continually reduced the SDM concentration in both DI water and lagoon wastewater. These results support SRB with TKPP as an effective composite for treating antibiotic residues in aquaculture discharge water.
Antibiotics, Volume 12; https://doi.org/10.3390/antibiotics12061024
This systematic review aimed to compare extended infusion or continuous infusion with bolus infusion for febrile neutropenia (FN). We included clinical trials comparing extended or continuous infusion with bolus infusion of beta-lactam antibiotics as empirical treatment for FN and evaluated the clinical failure, all-cause mortality, and adverse event rates. Five articles (three randomized controlled trials (RCTs) and two retrospective studies) from 2014 to 2022 were included. Clinical failure was assessed with a risk ratio (RR) (95% coincident interval (CI)) of 0.74 (0.53, 1.05) and odds ratio (OR) (95% CI) of 0.14 (0.02, 1.17) in the 2 RCTs and retrospective studies, respectively. All-cause mortality was assessed with an RR (95% CI) of 1.25 (0.44, 3.54) and OR (95% CI) of 1.00 (0.44, 2.23) in the RCTs and retrospective studies, respectively. Only 1 RCT evaluated adverse events (with an RR (95% CI) of 0.46 (0.13, 1.65)). The quality of evidence was “low” for clinical failure and all-cause mortality in the RCTs. In the retrospective studies, the clinical failure and all-cause mortality evidence qualities were considered “very low” due to the study design. Extended or continuous infusion of beta-lactam antibiotics did not reduce mortality better than bolus infusion but was associated with shorter fever durations and fewer adverse events.
Antibiotics, Volume 12; https://doi.org/10.3390/antibiotics12061023
Employing affordable and uncomplicated sample preparation techniques to recommend the most efficient antibacterial therapy could help reduce antibiotic-resistant bacteria. This study evaluated the suitability of immunoassays and microbiological assays as alternatives for liquid chromatography/mass spectrometry (LC/MS) in determining plasma tylosin concentrations after intramuscular administration at a dose of 20 mg/kg to both healthy and diseased pigs in clinical veterinary practice. The diseased pigs were confirmed using the target genes Actinobacillus pleuropneumoniae (apxIVA) and Pasteurella multocida (kmt1). The methods showed good linearity, precision, and accuracy. In both healthy and diseased pigs, a significant correlation was observed between LC/MS and the microbiological assay (Pearson correlation coefficient: 0.930, p < 0.001 vs. Pearson correlation coefficient: 0.950, p < 0.001) and between LC/MS and the enzyme-linked immunosorbent assay (ELISA) (Pearson correlation coefficient: 0.933; p < 0.001 vs. Pearson correlation coefficient: 0.976, p < 0.001). A strong correlation was observed between the microbiological assay and the ELISA in both healthy and diseased pigs (Pearson correlation coefficient: 0.911; p < 0.001 vs. Pearson correlation coefficient: 0.908, p < 0.001). A Bland-Altman analysis revealed good agreement between the methods, i.e., 95% of the differences were within the limits of agreement. Therefore, the microbiological assay and the ELISA, which demonstrated sufficient precision and accuracy, can be viable alternatives to LC/MS when it is unavailable.
Antibiotics, Volume 12; https://doi.org/10.3390/antibiotics12061022
Previous research suggests that the characteristics of both patients and physicians can contribute to the overuse of antibiotics. Until now, patients’ psychosocial characteristics have not been widely explored as a potential contributor to the overuse of antibiotics. In this study, the relationship between a patient’s psychosocial characteristics (self-reported in postal surveys in 2003) and the number of antibiotics they were prescribed (recorded in Finnish national registry data between 2004–2006) were analyzed for 19,300 working-aged Finns. Psychosocial characteristics included life satisfaction, a sense of coherence, perceived stress, hostility, and optimism. In a structural equation model, patients’ adverse psychosocial characteristics were not related to increased antibiotic prescriptions in the subsequent three years. However, these characteristics were strongly associated with poor general health status, which in turn was associated with an increased number of subsequent antibiotic prescriptions. Furthermore, mediation analysis showed that individuals who used healthcare services more frequently also received more antibiotic prescriptions. The current study does not support the view that patients’ adverse psychosocial characteristics are related to an increased number of antibiotic prescriptions. This could encourage physicians to actively discuss treatment options with their patients.
Antibiotics, Volume 12; https://doi.org/10.3390/antibiotics12061021
This study aimed to demonstrate that severe neurological motor deficits in the context of late tick-borne disease with mixed microorganism involvement are eligible for long-term combined antibiotic/antiparasitic treatments. The inclusion criteria were: 1. neurological limb paralysis with a disability score >4 according to the EDSS Kurtzke disability scale; 2. serological tests pointing to an involvement of the main tick-borne microorganisms Borrelia burgdorferi s.l., Babesia, Anaplasma, and Bartonella; 3. a general disease for more than 6 months with fatigue, pain and subjective cognitive deficit. The patients were administered long-term treatments with repeated cycles (at least three) of 35-day IV ceftriaxone and repeated oral regimens of azithromycin–doxycycline and azithromycin–doxycycline–rifampicin. For Babesia, repeated courses of atovaquone–azithromycin were administered. Ten patients had intractable or severe motor deficits before treatment in the context of Borrelia (two cases) Borrelia–Babesia (four cases), Borrelia–Babesia–Anaplasma (two cases), Borrelia–Babesia–Anaplasma–Bartonella (one case) and Babesia–Anaplasma (one case). For several months, five had been in wheelchairs, and four had been walking with sticks. Seven patients out of 10 (70%) showed complete remission after a mean active treatment duration of 20.1 + 6.6 months, with a mean number of 4 ceftriaxone cycles. Three patients showed an initial remission but suffered secondary antibiotic/antiparasitic-resistant motor recurrences. Among the nine patients with Borrelia serologic positivity, treatments obtained complete remission in seven cases (77%). The findings of this ten-case series suggest the usefulness of long-term antibiotic/antiparasitic treatments in patients with severe late tick-borne neurological deficits with highly significant elements of tick-borne involvement.
Antibiotics, Volume 12; https://doi.org/10.3390/antibiotics12061020
Epidemiological surveillance of nasopharyngeal pneumococcal carriage is important for monitoring serotype distribution and antibiotic resistance, particularly before and after the implementation of pneumococcal conjugate vaccines (PCVs). With a prospective surveillance study in France, we aimed to analyze the dynamics of pneumococcal carriage, antibiotic susceptibility and serotype distribution in children aged 6 to 24 months who had acute otitis media between 2001 and 2022 with a focus on the late PCV13 period from May 2014 to July 2022. Trends were analyzed with segmented linear regression with autoregressive error. For the 17,136 children enrolled, overall pneumococcal carriage was stable during the study. During the late PCV13 period, the five most frequent serotypes were all non-PCV13 serotypes: 15B/C (14.3%), 23B (11.0%), 11A (9.6%), 15A (7.4%) and 35B (6.5%). During the same period, we observed a rebound of penicillin non-susceptibility (+0.15% per month, 95% confidence interval, +0.08 to 0.22, p < 0.001). Five serotypes accounted for 64.4% of the penicillin non-susceptible strains: 11A (17.5%), 35B (14.9%), 15A (13.9%), 15B/C (9.9%) and 19F (8.2%); non-PCV13/PCV15 accounted for <1%, and non-PCV15/PCV20 accounted for 28%. The next generation PCVs, particularly PCV20, may disrupt nasopharyngeal carriage and contribute to decreasing the rate of antibiotic resistance among pneumococci.
Antibiotics, Volume 12; https://doi.org/10.3390/antibiotics12061019
The objectives of this study were to investigate the effects of group housing (three calves per group) on bovine respiratory disease (BRD), diarrhea and antimicrobial resistance (AMR) to fecal commensal Escherichia coli (EC) and enterococci/streptococci (ES). Our study comprised two arms, one experimental and one observational. In the experimental arm, preweaned calves on a California dairy were randomized to either individual (IND; n = 21) or group (GRP; n = 21) housing, using a modified California-style wooden hutch. The study period lasted from birth to 56 days of age, during which calves were health scored daily. Cumulative incidence and hazard ratios were estimated for disease. Antimicrobial resistance outcomes were assessed using a prospective cohort design; feces were collected from each calf three times per week and EC and ES were evaluated for AMR using the broth microdilution method against a panel of 19 antimicrobial drugs (AMD). Analysis of treatment records was used to select calves that had been exposed (EXP) to an AMD-treated calf. In GRP, exposure occurred when a calf was a hutchmate with an AMD-treated calf. In IND, exposure occurred when a calf was a neighbor with an AMD-treated calf (TRT). Age-matched unexposed calves (UNEXP) were then selected for comparison. Proportions of AMR in fecal commensals among EXP, UNEXP, and TRT calves were compared between GRP and IND. Accelerated failure time survival regression models were specified to compare differences in minimum inhibitory concentration (MIC) of fecal commensals between EXP and UNEXP calves within each of GRP and IND calves separately. Group calves had a BRD hazard 1.94 times greater that of IND calves (p = 0.03), using BRD treatment records as the outcome. For AMR in EC isolates, higher resistance to enrofloxacin was detected in enrofloxacin-EXP GRP isolates compared with enrofloxacin-EXP IND isolates, and UNEXP GRP calves had lower resistance to ceftiofur compared with enrofloxacin-EXP and enrofloxacin-TRT calves. A significant housing-by-time interaction was detected for EC ceftiofur MIC in EXP GRP calves at 4–14 days post exposure to enrofloxacin (MIC EXP-UNEXP: µg/mL (95% CI): 10.62 (1.17, 20.07)), compared with UNEXP calves. The findings of this study show an increase in BRD hazard for group-housed calves and an increase in ceftiofur resistance in group-housed calves exposed to an enrofloxacin-treated calf.
Antibiotics, Volume 12; https://doi.org/10.3390/antibiotics12061018
Antibiotics are one of the most frequently dispensed classes of medicines. However, excessive misuse and abuse enhances antimicrobial resistance (AMR). Previous studies in Pakistan have documented extensive dispensing of ‘Watch’ and ‘Reserve’ antibiotics, which is a concern. In view of this, there is a need to assess current dispensing patterns following COVID-19 in Pakistan. A cross-sectional study was undertaken, collecting dispensing data from 39 pharmacies and 53 drug stores from November 2022 to February 2023. Outlets were principally in urban areas (60.9%), with pharmacists/pharmacy technicians present in 32.6% of outlets. In total, 11,092 prescriptions were analyzed; 67.1% of patients were supplied at least one antimicrobial, 74.3% antibiotics, 10.2% antifungals and 7.9% anthelmintics. A total of 33.2% of antimicrobials were supplied without a prescription. Common indications for dispensed antibiotics were respiratory (34.3%) and gastrointestinal (16.8%) infections, which can be self-limiting. In addition, 12% of antibiotics were dispensed for the prevention or treatment of COVID-19. The most frequent antibiotics dispensed were ceftriaxone (18.4%) and amoxicillin (15.4%). Overall, 59.2% antibiotics were ‘Watch’ antibiotics, followed by ‘Access’ (40.3%) and ‘Reserve’ (0.5%) antibiotics. Of the total antibiotics dispensed for treating COVID-19, 68.3% were ‘Watch’ and 31.7% ‘Access’. Overall, there appeared to be an appreciable number of antibiotics dispensed during the recent pandemic, including for patients with COVID-19, alongside generally extensive dispensing of ‘Watch’ antibiotics. This needs to be urgently addressed with appropriate programs among pharmacists/pharmacy technicians to reduce AMR.
Antibiotics, Volume 12; https://doi.org/10.3390/antibiotics12061017
Indole, a metabolite of the amino acid tryptophan, has been proven to act as a signal molecule in bacteria, acting in different aspects of biofilm formation. The oral biofilm is a type of biofilm that has consequences for human health. It is a complex, three-dimensional structure that develops on the surface of teeth via the attachment of primary microbial colonizers. Many oral infections are caused by an imbalance occurring in the microorganisms naturally found in oral biofilms and are considered major public health concerns. In this study, we test the effect of a natural bis-indole, 3,3′-Diindolylmethane (DIM), in mitigating the pathogenicity of the oral biofilm inhabiting bacterium Streptococcus mutans, a bacterium that is considered to be a principal etiological agent in dental caries. Our study found that DIM was able to attenuate S. mutans biofilm formation by 92%. Additionally, treatment with DIM lowered extracellular polymeric substance (EPS) production and decreased its durability significantly under acidic conditions. Therefore, the anti-biofilm and anti-virulence properties of DIM against S. mutans bacteria in an “oral setting” provides evidence for its usefulness in reducing biofilm formation and potentially for caries attenuation.