A spatial-genomic analysis reveals that bird species living closer to humans have higher diversity of the pathogen Campylobacter and its antimicrobial resistance genes. This suggests that urbanization could promote pathogen transmission among wild animals and, potentially, humans.

OBJECTIVE: The mannose phosphotransferase system (Man-PTS) plays crucial roles in the adaptive metabolic activity of Enterococcus faecalis (E. faecalis) in adverse environments. The aim of this study was to evaluate the role of Man-PTS in the alkaline resistance of E. faecalis against calcium hydroxide (CH) and the effect of metformin (Met) on the alkaline resistance of E. faecalis to CH.
METHODS: The regulatory role of Man-PTS EII in the alkaline resistance of E. faecalis was firstly investigated using a wild-type highly alkaline-resistant E. faecalis XS 003, standard ATCC 29212 and Man-PTS EIID gene deficient (△mptD) and overexpressing (+mptD)  strains of E. faecalis. RNA sequencing of Met-treated E. faecalis was performed to further validate the effect of Met on Man-PTS. The effect of Met on CH resistance of E. faecalis was verified by evaluating the survival, membrane potential and permeability, intracellular pH and ATP, and the expression of Man-PTS EII and membrane transporter-related genes of E. faecalis. The effect of Met on the ability of CH to remove E. faecalis biofilm on the dentin surface was also tested. The in vivo therapeutic effect of Met plus CH (CHM) was further investigated in a rat apical periodontitis model induced by E. faecalis XS 003.
RESULTS: Man-PTS EII significantly promoted the survival ability of E. faecalis in CH and enhanced its resistance to CH. The inhibition of Man-PTS EII by Met resulted in reduced alkaline resistance of E. faecalis in the presence of CH, while also enhancing the antimicrobial properties of CH against E. faecalis biofilm on dentin. Additionally, Met plus CH showed the synergistically promoted intra-canal E. faecalis infection control and healing of periapical lesion in rats.
CONCLUSIONS: Met could significantly reduce the alkaline resistance of E. faecalis against CH through the modulation of Man-PTS EII, and improved the antibacterial effect of CH against E. faecalis infection both in vitro and in vivo.
CONCLUSIONS: Met could significantly enhance the ability of CH to control E. faecalis infection through reducing the alkaline resistance of E. faecalis.

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OBJECTIVE: The purpose of this study is a new update on the resistance profile, Macrolide-Lincosamide-Streptogramin B resistance mechanisms and biofilm formation in the Staphylococcus aureus isolated from health care workers (HCWs) nasal carriage at a children\'s teaching hospital in Babol (Northern Iran).
RESULTS: A total of 143 non-repetitive nasal swab samples were collected from volunteers, where 53.8% (n; 77/143) were HCWs, 33.6% (n; 48/143) medical students, and 12.6% (n; 18/143) resident students. The prevalence of nasal carriers of S. aureus was 22.4% (n; 32/143), among them, 40.6% (n; 13/32) were identified as methicillin-resistant Staphylococcus aureus (MRSA( carriers. Antimicrobial susceptibility testing showed that erythromycin (68.8%, n; 22/32) and ciprofloxacin (15.6%, n; 5/32) had the highest and lowest resistance rate, respectively. The frequency of resistance genes in the strains was as follows; ermC (n; 17/32, 53.1%), ermA (n; 11/32, 34.4%), ermB (n; 6/32, 18.7%), ereA (n; 3/32, 9.4%). Moreover, 50.0% (n; 16/32), 28.1% (n; 9/32) and 21.8% (n; 7/32) of isolates were strongly, weakly and moderately biofilm producer, respectively. Macrolides-lincosamides-streptogramins B (MLSB) antibiotic resistance among S. aureus isolates from HCWs nasal carriage have found significant prevalence rates throughout the globe. It is crucial to remember that the development of biofilms and MLS B antibiotic resistance are both dynamic processes.

BACKGROUND: Helicobacter pylori infects the stomach and/or small intestines in more than half of the human population. Infection with H. pylori is the most common cause of chronic gastritis, which can lead to more severe gastroduodenal pathologies such as peptic ulcer, mucosa-associated lymphoid tissue lymphoma, and gastric cancer. H. pylori infection is particularly concerning in Colombia in South America, where > 80% of the population is estimated to be infected with H. pylori and the rate of stomach cancer is one of the highest in the continent.
RESULTS: We compared the antimicrobial susceptibility profiles and short-read genome sequences of five H. pylori isolates obtained from patients diagnosed with gastritis of varying severity (chronic gastritis, antral erosive gastritis, superficial gastritis) in Pereira, Colombia sampled in 2015. Antimicrobial susceptibility tests revealed the isolates to be resistant to at least one of the five antimicrobials tested: four isolates were resistant to metronidazole, two to clarithromycin, two to levofloxacin, and one to rifampin. All isolates were susceptible to tetracycline and amoxicillin. Comparative genome analyses revealed the presence of genes associated with efflux pump, restriction modification systems, phages and insertion sequences, and virulence genes including the cytotoxin genes cagA and vacA. The five genomes represent three novel sequence types. In the context of the Colombian and global populations, the five H. pylori isolates from Pereira were phylogenetically distant to each other but were closely related to other lineages circulating in the country.
CONCLUSIONS: H. pylori from gastritis of different severity varied in their antimicrobial susceptibility profiles and genome content. This knowledge will be useful in implementing appropriate eradication treatment regimens for specific types of gastritis. Understanding the genetic and phenotypic heterogeneity in H. pylori across the geographical landscape is critical in informing health policies for effective disease prevention and management that is most effective at local and country-wide scales. This is especially important in Colombia and other South American countries that are poorly represented in global genomic surveillance studies of bacterial pathogens.

BACKGROUND: Continuous monitoring of antimicrobial resistance (AMR) in Uganda involves testing bacterial isolates from clinical samples at national and regional hospitals. Although the National Microbiology Reference Laboratory (NMRL) analyzes these isolates for official AMR surveillance data, there\'s limited integration into public health planning. To enhance the utilization of NMRL data to better inform drug selection and public health strategies in combating antibiotic resistance, we evaluated the trends and spatial distribution of AMR to common antibiotics used in Uganda.
METHODS: We analyzed data from pathogenic bacterial isolates from blood, cerebrospinal, peritoneal, and pleural fluid from AMR surveillance data for 2018-2021. We calculated the proportions of isolates that were resistant to common antimicrobial classes. We used the chi-square test for trends to evaluate changes in AMR resistance over the study period.
RESULTS: Out of 537 isolates with 15 pathogenic bacteria, 478 (89%) were from blood, 34 (6.3%) were from pleural fluid, 21 (4%) were from cerebrospinal fluid, and 4 (0.7%) were from peritoneal fluid. The most common pathogen was Staphylococcus aureus (20.1%), followed by Salmonella species (18.8%). The overall change in resistance over the four years was 63-84% for sulfonamides, fluoroquinolones macrolides (46-76%), phenicols (48-71%), penicillins (42-97%), β-lactamase inhibitors (20-92%), aminoglycosides (17-53%), cephalosporins (8.3-90%), carbapenems (5.3-26%), and glycopeptides (0-20%). There was a fluctuation in resistance of Staphylococcus aureus to methicillin (60%-45%) (using cefoxitin resistance as a surrogate for oxacillin resistance) Among gram-negative organisms, there were increases in resistance to tetracycline (29-78% p < 0.001), ciprofloxacin (17-43%, p = 0.004), ceftriaxone (8-72%, p = 0.003), imipenem (6-26%, p = 0.004), and meropenem (7-18%, p = 0.03).
CONCLUSIONS: The study highlights a concerning increase in antibiotic resistance rates over four years, with significant increase in resistance observed across different classes of antibiotics for both gram-positive and gram-negative organisms. This increased antibiotic resistance, particularly to commonly used antibiotics like ceftriaxone and ciprofloxacin, makes adhering to the WHO\'s Access, Watch, and Reserve (AWaRe) category even more critical. It also emphasizes how important it is to guard against the growing threat of antibiotic resistance by appropriately using medicines, especially those that are marked for \"Watch\" or \"Reserve.\"

Objective: This study aimed to evaluate antibiotic susceptibility and antimicrobial resistance trends among clinically significant anaerobes in Kuwait hospitals from 2013 to 2022, comparing these findings with data from 2002 to 2012. Methods: The study prospectively collected 2,317 anaerobic isolates from various body sites across four Kuwaiti hospitals between January 2013 and December 2022. The minimum inhibitory concentrations for 11 antianaerobic antibiotics were determined using E-test methodology. The study analyzed trends and resistance rates across two periods: 2013-2017 and 2018-2022, using statistical analysis for resistance comparison. Results: Of the 2,317 isolates, most were from wounds (42.2%), fluids (28.0%), and tissues (20.5%). Bacteroides fragilis was the most common pathogen (34.0%), followed by Prevotella bivia (13.4%). Over 90% of isolates were susceptible to imipenem, meropenem, tigecycline, and metronidazole, whereas lower susceptibility was observed for penicillin, amoxicillin-clavulanic acid, and clindamycin. Notable differences in resistance profiles since 2002 were observed, especially in amoxicillin-clavulanic acid, piperacillin, piperacillin-tazobactam, and clindamycin. Conclusion: Owing to detected resistance to all antibiotics, susceptibility testing for anaerobic isolates is recommended in severe infections to ensure effective antimicrobial therapy. Continuous surveillance is crucial for developing antibiotic policies to manage invasive anaerobic infections.

Antibiotic tolerance in Mycobacterium tuberculosis reduces bacterial killing, worsens treatment outcomes, and contributes to resistance. We studied rifampicin tolerance in isolates with or without isoniazid resistance (IR). Using a minimum duration of killing assay, we measured rifampicin survival in isoniazid-susceptible (IS, n=119) and resistant (IR, n=84) isolates, correlating tolerance with bacterial growth, rifampicin minimum inhibitory concentrations (MICs), and isoniazid-resistant mutations. Longitudinal IR isolates were analyzed for changes in rifampicin tolerance and genetic variant emergence. The median time for rifampicin to reduce the bacterial population by 90% (MDK90) increased from 1.23 days (IS) and 1.31 days (IR) to 2.55 days (IS) and 1.98 days (IR) over 15-60 days of incubation, indicating fast and slow-growing tolerant sub-populations. A 6 log10-fold survival fraction classified tolerance as low, medium, or high, showing that IR is linked to increased tolerance and faster growth (OR = 2.68 for low vs. medium, OR = 4.42 for low vs. high, p-trend = 0.0003). High tolerance in IR isolates was associated with rifampicin treatment in patients and genetic microvariants. These findings suggest that IR tuberculosis should be assessed for high rifampicin tolerance to optimize treatment and prevent the development of multi-drug-resistant tuberculosis.

BACKGROUND: Antimicrobial resistance poses a significant threat to public health globally. We studied the prevalence of colonization with extended-spectrum cephalosporin-resistant Enterobacterales (ESCrE), carbapenem-resistant Enterobacterales (CRE), and colistin-resistant Enterobacterales (Col-RE) in hospitals and the surrounding community in South India.
METHODS: Adults from 2 hospitals and the catchment community who consented to provide stool specimens were enrolled. Stools were plated on CHROMagar selective for ESCrE, CRE, and Col-RE. Bacterial identification and antibiotic susceptibility testing were done using Vitek 2 Compact and disc diffusion testing. Colistin broth microdilution was performed for a subset of isolates. Prevalence estimates were calculated with 95% confidence intervals (CIs), and differences were compared across populations using the Pearson χ  2 or Fisher exact test.
RESULTS: Between November 2020 and March 2022, 757 adults in the community and 556 hospitalized adults were enrolled. ESCrE colonization prevalence was 71.5% (95% CI, 68.1%-74.6%) in the community and 81.8% (95% CI, 78.4%-84.8%) in the hospital, whereas CRE colonization prevalence was 15.1% (95% CI, 12.7%-17.8%) in the community and 22.7% (95% CI, 19.4%-26.3%) in the hospital. Col-RE colonization prevalence was estimated to be 1.1% (95% CI, .5%-2.1%) in the community and 0.5% (95% CI, .2%-1.6%) in the hospital. ESCrE and CRE colonization in hospital participants was significantly higher compared with community participants (P < .001 for both).
CONCLUSIONS: High levels of colonization with antibiotic-resistant Enterobacterales were found in both community and hospital settings. This study highlights the importance of surveillance of colonization in these settings for understanding the burden of antimicrobial resistance.

This study proposes an innovative approach to combat the escalating threat of antibiotic resistance in bacteria by introducing a novel ZnO-propolis nanocomposite (ZnO-P NCs). The overuse of antibiotics, particularly during events like the COVID-19 pandemic, has intensified bacterial resistance, necessitating innovative solutions. The study employs a cost-effective and controllable biosynthesis method to produce ZnO nanoparticles (ZnO-NPs), with propolis extract crucially contributing to the reduction and stabilization of Zn2+ ions. A biodegradable nano-propolis matrix is then created by incorporating ZnO-NPs, forming the ZnO-P NCs. Structural stability is confirmed through FT-IR and Zeta potential analysis, while nanoscale properties are validated via TEM, SEM, and XRD analyses. The antimicrobial efficacy of various substances, including propolis, nano propolis, ethanolic propolis extract, ZnO-NPs, and ZnO-P NCs, is assessed against Gram-negative and Gram-positive bacteria, alongside a comparison with 28 antibiotics. Among the bacteria tested, Pseudomonas aeruginosa PAO1 ATCC15692 was more sensitive (40 mm) to the biosynthesized nanocomposite ZnO-P NCs than to ZnO-NPs (38 mm) and nanopropolis (32 mm), while Escherichia coli was resistant to nanopropolis (0 mm) than to ZnO-NPs (31 mm), and ZnO-P NCs (34 mm). The study reveals a synergy effect when combining propolis with green-synthesized ZnO-NPs in the form of ZnO-P NCs, significantly improving their efficiency against all tested bacteria, including antibiotic-resistant strains like E. coli. The nanocomposite outperforms other materials and antibiotics, demonstrating remarkable antibacterial effectiveness. SEM imaging confirms the disruption of bacterial cell membranes by ZnO-NPs and ZnO-P NCs. The study emphasizes the potential applications of ZnO-NPs integrated into biodegradable materials and underscores the significance of the zinc oxide-propolis nanocomposite in countering antimicrobial resistance. Overall, this research offers a comprehensive solution to combat multidrug-resistant bacteria, opening avenues for novel approaches in infection control.