Background: H. pylori (Helicobacter pylori) infections typically occur in early childhood. Although the prevalence of H. pylori in children is lower than that in adults, the eradication rate of this infection in children is relatively low because of resistance. In this study, we analyzed personalized treatment strategies to achieve treatment goals based on H. pylori resistance characteristics. This retrospective single-center study was conducted between January 2019 and December 2022 and enrolled 1,587 children who presented with upper gastrointestinal symptoms and underwent endoscopy. H. pylori culturing and antimicrobial susceptibility testing were performed. Results: Culture-positive results for H. pylori were obtained in 535 children. The resistance rates to clarithromycin (CLA), metronidazole (MET), and levofloxacin (LEV) were 39.8%, 78.1%, and 20.2%, respectively. None of the isolates were resistant to tetracycline (TET), amoxicillin (AMO), or furazolidone (FZD). Double resistance rates to CLA + MET, CLA + LEV, and MET + LEV were 19.1%, 3.0%, and 5.8%, respectively. Notably, triple-resistant to CLA + MET + LEV was 9.7%. Based on susceptibility tests, individualized triple therapy [proton pump inhibitor (PPI) +AMO + CLA/MET] was selected for 380 children with H. pylori sensitive to MET and/or CLA. In 155 children resistant to CLA and MET, bismuth-based quadruple therapy was recommended; for unable to receive bismuth, concomitant therapy was recommended for 14 children (<8 years of age); triple therapy with TET was recommended for 141 children (>8 years of age), with 43 children (>14 years of age) requiring FZD rather than TET. Conclusion: Resistance to H. pylori in Chinese children was relatively poor. Personalized therapy regimens should be based on susceptibility tests and avoided factors associated with treatment failure.

Current global variations exist in Helicobacter pylori (H. pylori) eradication regimens. Triple therapy (TT), bismuth quadruple therapy (BQT), and high-dose dual therapy (HDDT) currently represent the predominant regimens. These regimens diverge in terms of treatment duration, the utilization of susceptibility testing, acid-inhibiting drug administration, and patient education. We conducted a comprehensive systematic literature review on these H. pylori treatment regimens. Our review aims to provide standardized treatment recommendations for H. pylori, reducing the risk of amalgamating findings from diverse eradication regimens. Recent research suggests that the optimal treatment duration for TT and BQT may be 14 and 10 days, respectively. Selecting the appropriate treatment duration for HDDT should rely on regional research evidence, and 14 days may be the optimal duration. The incorporation of susceptibility testing in TT is of paramount importance. In the case of BQT, the absence of susceptibility testing may be considered as an option, contingent upon cost and availability, and should be determined based on local antibiotic resistance patterns and the efficacy of empirical regimens. The type and dosage of acid-inhibiting drug would affect the efficacy of these regimens. Acid-inhibiting drugs should be selected and applied reasonably according to the population and therapies. Adequate patient education plays a pivotal role in the eradication of H. pylori. In regions with accessible local research evidence, the 10-day empirical BQT regimen may be considered a preferred choice for H. pylori eradication.

Antibiotic resistance is a major 21st century One Health (humans, animals, environment) challenge whose spread limits options to treat bacterial infections. There is growing interest in monitoring water environments, including surface water and wastewater, which have been identified as key recipients, pathways, and sources of antibiotic resistant bacteria (ARB). Aquatic environments also facilitate the transmission and amplification of ARB. Enterococcus spp. often carry clinically-important antibiotic resistance genes and are of interest as environmental monitoring targets. Enterococcus spp. are Gram-positive bacteria that are typically of fecal origin; however, they are also found in relevant environmental niches, with various species and strains that are opportunistic human pathogens. Although the value of environmental monitoring of antibiotic-resistant Enterococcus has been recognized by both national and international organizations, lack of procedural standardization has hindered generation of comparable data needed to implement integrated surveillance programs. Here we provide a comprehensive methodological review to assess the techniques used for the culturing and characterization of antibiotic-resistant Enterococcus across water matrices for the purpose of environmental monitoring. We analyzed 117 peer-reviewed articles from 33 countries across six continents. The goal of this review is to provide a critical analysis of (i) the various methods applied globally for isolation, confirmation, and speciation of Enterococcus isolates, (ii) the different methods for profiling antibiotic resistance among enterococci, and (iii) the current prevalence of resistance to clinically-relevant antibiotics among Enterococcus spp. isolated from various environments. Finally, we provide advice regarding a path forward for standardizing culturing of Enterococcus spp. for the purpose of antibiotic resistance monitoring in wastewater and wastewater-influenced waters within a global surveillance framework.

Bacillus anthracis, the causative agent of anthrax, is a high-consequence bacterial pathogen that occurs naturally in many parts of the world and is considered an agent of biowarfare or bioterrorism. Understanding antimicrobial susceptibility profiles of B. anthracis isolates is foundational to treating naturally occurring outbreaks and to public health preparedness in the event of an intentional release. In this systematic review, we searched the peer-reviewed literature for all publications detailing antimicrobial susceptibility testing of B. anthracis. Within the set of discovered articles, we collated a subset of publications detailing susceptibility testing that followed standardized protocols for Food and Drug Administration-approved, commercially available antimicrobials. We analyzed the findings from the discovered articles, including the reported minimal inhibitory concentrations. Across the literature, most B. anthracis isolates were reported as susceptible to current first-line antimicrobials recommended for postexposure prophylaxis and treatment. The data presented for potential alternative antimicrobials will be of use if significant resistance to first-line antimicrobials arises, the strain is bioengineered, or first-line antimicrobials are not tolerated or available.

Helicobacter canis, an enterohepatic Helicobacter, has proven its role in human diseases and has been rediscussed in recent years as its zoonotic potential is increasingly described. Routine microbiological detection of this pathogen is a difficult task as its culture may fail due to fastidious growth. It is therefore supposed that many clinical laboratories under-recognize H. canis infections. A review of all clinical and microbiological literature currently available from previous relevant H. canis human clinical cases, mainly bacteremia, added with a clinical case observed at the Cliniques universitaires Saint-Luc, was performed. Clinical features of H. canis reports show the presence of underlying clinical conditions in 89% of the cases, bacteremia in 83%, associated fever in 58%, and recent close contact with pets in 83%, especially dogs. The observed microbiological trends from 10 cases of bacteremia were a median of 4 days until positive blood culture bottle detection, subcultures showing a thin layer of small colonies under microaerophilic atmosphere at 35-42°C after 3-4 days of growth, and an identification requiring 16S rRNA sequencing given the difficulties observed with MALDI-TOF MS. Low MICs were observed for penicillins, amoxicillin/clavulanic acid, carbapenems, and metronidazole in opposition to high MICs for ciprofloxacin. A frequent association of H. canis and bacteremia in immunocompromised patients with recurrent fever in contact with pets, especially dogs, was identified. Considering the fastidious growing capacities, final identification from blood cultures may not be expected before 7 days. Intravenous ceftriaxone, oral doxycycline, or metronidazole has been suggested as efficient therapeutic choices.

Chlorhexidine digluconate (CHG) is an antiseptic frequently used in hospitals to prevent healthcare-related infections. It is used in different formulations for skin antisepsis, oral care, patient bathing, and hand hygiene. Also, CHG impregnated vascular catheters and wound dressings contribute to increased exposure of hospital germs to this biocide. In the last decade, concerns are rising about decreasing susceptibility of microorganisms to CHG and its potential cross-resistance with antibiotics. This study reviewed the published data regarding the evidence of reduced CHG susceptibility, the cross-resistance with antibiotics, and the implications for infection control for S. aureus, coagulase-negative staphylococci, E. coli, K. pneumoniae, and P. aeruginosa. Despite incongruity in definitions of \"resistance,\" increased CHG minimal inhibitory values of these pathogens have been described, and different mutations encoding for CHG efflux pumps have been identified. Clinical relevance of species with reduced susceptibility to CHG is debatable and cross-resistance with antibiotics remains controversial. However, some studies link the increased usage of CHG to multidrug resistance, and the potential cross-resistance with colistin for K. pneumoniae is of major concern. More research in this matter is necessary. For infection control, it is advisable to use CHG applications only for indications with a clear patient benefit. It is important to follow manufacturer\'s instructions, and exposure of microorganisms to sub-lethal CHG concentrations should be avoided.

Antibiotic de-escalation is an appealing strategy in antibiotic stewardship programmes. We aimed to assess its safety and effects using a systematic review and meta-analysis. We included randomized controlled trials (RCTs) and observational studies assessing adults with bacteraemia, microbiologically documented pneumonia or severe sepsis, comparing between antibiotic de-escalation and no de-escalation. De-escalation was defined as changing an initially covering antibiotic regimen to a narrower spectrum regimen based on antibiotic susceptibility testing results within 96 hours. The primary outcome was 30-day all-cause mortality. A search of published articles and conference proceedings was last updated in September 2015. Crude and adjusted ORs with 95% CI were pooled in random-effects meta-analyses. Sixteen observational studies and three RCTs were included. Risk of bias related to confounding was high in the observational studies. De-escalation was associated with fewer deaths in the unadjusted analysis (OR 0.53, 95% CI 0.39-0.73), 19 studies, moderate heterogeneity. In the adjusted analysis there was no significant difference in mortality (adjusted OR 0.83, 95% CI 0.59-1.16), 11 studies, moderate heterogeneity and the RCTs showed non-significant increased mortality with de-escalation (OR 1.73, 95% 0.97-3.06), three trials, no heterogeneity. There was a significant unadjusted association between de-escalation and survival in bacteraemia/severe sepsis (OR 0.45, 95% CI 0.30-0.67) and ventilator-associated pneumonia (OR 0.49, 95% CI 0.26-0.95), but not with other pneumonia (OR 0.97, 95% CI 0.45-2.12). Only two studies reported on the emergence of resistance with inconsistent findings. Observational studies suggest lower mortality with antibiotic susceptibility testing-based de-escalation for bacteraemia, severe sepsis and ventilator-associated pneumonia that was not demonstrated in RCTs.

The objective of this paper was to perform a critical review of the literature as it pertains to the current status of antimicrobial resistance in pathogens associated with bovine respiratory disease (BRD) in beef cattle and to provide a concise yet informative narrative on the most relevant publications available. As such, the scientific literature contained in PubMed, AGRICOLA, and CAB were searched in February of 2014 for articles related to susceptibility testing of Mannheimia haemolytica, Pasteurella multocida, and Histophilus somni from cases of BRD. Titles and abstracts were read and 105 articles that were relevant to the subject of BRD antibiotic resistance were attained for further review. After the application of exclusion criterion (publications must have originated from North America, be in English, adhere to standards set forth by the Clinical and Laboratory Standards Institute, and be concerning antimicrobial resistance in BRD in beef cattle), 16 articles remained and are the focus of this publication. Due to the disparate data from the few studies that investigate susceptibility testing of BRD pathogens, a quantitative assessment or meta-analysis was not performed on the studies presented in this review. However, considering diagnostic lab data, there appears to be a clear trend of a decrease in susceptibility of the three major BRD pathogens to the antimicrobials used commonly for treatment and control of BRD. Studies performing sensitivity testing on healthy cattle report much lower resistance, but it remains unclear if this is because of a true lack of resistance mechanisms, or if the isolates do contain quiescent genes for resistance that are only phenotypically expressed following the administration of an antimicrobial for either treatment or control of BRD. Future research to address this question of genotype and phenotypic expression before and after antimicrobial administration will further advance our knowledge in this area.

BACKGROUND: Fluoroquinolones (FQs) are used for drug-susceptible tuberculosis (TB) in patients unable to tolerate first-line agents. Current trials are also investigating these drugs in empiric first-line TB therapy, to improve outcomes and allow for shortened treatment regimens. Widespread FQ use in the community has resulted in FQ resistance in many microorganisms, including Mycobacterium tuberculosis. Despite this, FQ drug susceptibility testing (DST) is rarely performed in non-multidrug-resistant TB (non-MDR-TB).
METHODS: We conducted a 1-year surveillance study of FQ resistance on all MTB isolates from New South Wales (NSW), Australia. In addition, we performed a literature review of previous studies assessing FQ resistance in non-MDR-TB to summarize the global extent of this resistance pattern.
RESULTS: Two (0.6%) out of 357 MTB isolates from NSW were found to be FQ-resistant. One isolate was an MDR strain (11% of all MDR-TB). The other was isoniazid-monoresistant (0.3% of all non-MDR-TB). Eleven studies from 10 countries had performed FQ resistance surveillance on non-MDR-TB. In the majority of these studies, FQ resistance was found to be low (mean 1%; 95% confidence interval 0.2-2%).
CONCLUSIONS: FQ resistance in non-MDR-TB is uncommon in NSW, Australia. The existing global evidence suggests that FQ resistance remains largely confined to MDR-TB strains. In the majority of TB endemic regions, however, FQ resistance in non-MDR-TB has not been assessed. Knowledge of the prevalence of FQ resistance in MTB is essential to guide the rational use of these drugs, including their feasibility as first-line agents.