Changes in antimicrobial resistance patterns of ocular surface bacteria isolated from horses in the UK: An eight‐year surveillance study (2012‐2019)

Trends in antibiotic resistance in ocular samples in a tertiary eye centre in Saudi Arabia in 2003–2019

In mature animals histamine infusion typically causes an H1-mediated increase and H2-mediated decrease in pulmonary vascular resistance (PVR). Moreover, low histamine concentrations can cause H1-mediated relaxation of vascular strips in mature animals, and in newborn animals histamine infusion causes only H1-mediated decreases in PVR. The mechanisms responsible for the different H1-mediated responses are unknown. We used an inflow-outflow occlusion technique to identify the sites of H1- and H2-mediated responses in lungs of developing lambs. Histamine was infused at 1.0 and 10.0 micrograms.kg-1.min-1 in control and H1- and H2-blocked lungs of newborn and juvenile lambs under "normoxic" and hypoxic conditions and in hypoxic H2-blocked lungs of mature sheep. In newborns histamine caused significant H1-mediated decreases in resistance across the arterial (delta Pa) and middle (delta Pm) segments of the circuit during both normoxia and hypoxia. In normoxic juveniles low-dose histamine caused H1-mediated decreases in the resistance across delta Pa and delta Pm, but the resistances across delta Pm rose above baseline at the higher dose. The venous segment exhibited only a high-dose increase in resistance. During hypoxia, the high-dose H1-mediated pressor response of delta Pm was attenuated compared with that during normoxia; however, the increase in venous resistance was unaffected. In hypoxic mature sheep, no low dose H1-mediated decrease in segmental resistances was seen, but at the higher dose an increase in all resistances occurred.(ABSTRACT TRUNCATED AT 250 WORDS)

The increasing incidences of antibiotic-resistant infections is a significant concern in managing complicated wound healing. This study examines the trends and microbiological profiles of infected wounds treated surgically at the National Research Center for Traumatology and Orthopedics named after Academician N.D. Batpenov in Astana, Kazakhstan, from 2021 to 2023. A retrospective analysis was conducted on patients who underwent surgical wound closure between 2021 and 2023. Data on patient age, length of hospital stay, comorbidities, type of trauma, chronicity of the condition, affected body part, initial diagnosis, and microbiological culture results were collected. The study assessed the frequency and patterns of antibiotic resistance among isolated pathogens. In 2021, 56 patients were included, with an average age of 43±14.7 years and an average hospital stay of 22.25±11.6 days. Trauma types varied, with a significant proportion resulting from traffic accidents and burns. In 2022, 21 patients (average age 43.9±12.2 years) had longer hospital stays (37.5±23.4 days). The primary diagnoses included osteomyelitis and acute injuries. In 2023, 33 patients were studied, with a mean age of 42.5±27 years and an average stay of 12.6±11 days. Notably, the proportion of patients with osteomyelitis increased over the 3 years. Microbiological analysis revealed a growing presence of antibiotic-resistant pathogens. Staphylococcus aureus (24%) and Pseudomonas aeruginosa (12%) were the most commonly isolated bacteria, with a significant increase in resistance to beta-lactams and other antibiotic groups. The emergence of multi-drug resistant Klebsiella pneumoniae and Acinetobacter species was also observed. The study highlights a concerning trend of increasing antibiotic resistance in pathogens isolated from infected wounds. This underscores the need for ongoing surveillance, updated treatment protocols, and the judicious use of antibiotics to manage such infections effectively. Further research is required to develop strategies to combat the rise of antibiotic-resistant infections.

Development of antibiotic resistance among common respiratory pathogens is a major cause of concern worldwide. Streptococcus pneumoniae and Haemophilus influenzae are among the most common respiratory pathogens. In this study, representative samples obtained from 3 different medical centers in Dakar, Senegal were subjected to antibiotic susceptibility testing. The samples were collected from 2005 to 2008 and the data obtained was compared to establish resistance patterns between the two years (i.e. 2005–2006 to 2007–2008). S. pneumoniae exhibited a significant increase in the resistance to azithromycin and the intermediate susceptibility to penicillin G and cotrimoxazole. H. influenzae also exhibited a significant increase in resistance to azithromycin and intermediate susceptibility to chloramphenicol. None of H. influenzae samples were resistant to amoxicillin/clavulanic acid, cephalosporin and fluroquinolones and most of the S. pneumoniae isolates demonstrated high susceptibility to the antibiotics tested. Results from this study will provide greater insights to antibiotic therapy during respiratory tract infections in Dakar, Senegal. This study also establishes the importance of continuous monitoring of antibiotic susceptibility patterns that are often region-specific.

Bacterial resistance is a global phenomenon, but it presents geographic and temporal variations; this is the importance of local surveillance programs. To determine trends in antibiotic resistance in hospitals between 2007 and 2012 in Medellín and its Metropolitan Area. Percentages of antibiotic resistance between 2007 and 2012 in 22 institutions were obtained using WHONET 5.6 program. For interpretation of susceptibility results, CLSI standards of 2009 and 2012 were used. Using the Epi-Info 6.04 program a trends analysis of antibiotic resistance was done using the chi-square for linear trend with a confidence level of 95%, a value of p=0.05 was considered significant. In six years of surveillance of antibiotic resistance we found a decrease of oxacillin resistance in Staphylococcus aureus (p=0.0006) and an increase of vancomycin resistance in Enterococcus faecium (p=0.0000). In Escherichia coli and Serratia marcescens an increase of resistance to ceftazidime was found, in contrast to a decrease in Klebsiella pneumoniae (p=0.0000) and Enterobacter cloacae (p=0.058). K. pneumoniae , S. marcescens and E. cloacae showed an increase of carbapenem resistance in contrast to a reduction of carbapenem resistance in Pseudomonas aeruginosa and Acinetobacter baumannii . The resistance surveillance identified important findings as the emergence of E. faecium resistant to vancomycin and carbapenem-resistant Enterobacteriaceae . It is essential to determine the antibiotic use in the region to establish their influence on the resistance profiles, as well as ensuring the quality of information and microbiological procedures in the microbiology laboratories.

BackgroundThe purpose of this study was to determine the shifting trends in bacteriology and antimicrobial resistance of infectious specimens isolated from gastrointestinal (GI) fistula patients over eight years in China.MethodsWe retrospectively reviewed the microbial records of intra-abdominal specimens at a teaching hospital from 2008 to 2015. Study period was divided into the first half (2008–2011) and the second half (2012–2015). All isolates underwent antibiotic susceptibility testing by the micro dilution method.ResultsA total of 874 intra-abdominal isolates were consecutively collected from 502 GI fistula patients (mean age, 46.5 years, 71.1% male) during the study period. Patients in the second study period (2012–2015) were older (>65 years) and more likely to have experienced cancer. Over the entire study period, most infections were caused by E. coli (24.2%) and K. pneumonia (14.1%). There was a significant decrease in the proportion E. coli isolates that were extended- spectrum beta-lactamase (ESBL)-positive (P = 0.026). The proportion of E. coli resistant to imipenem increased from 14.3% in 2008–2011 to 25.9% in 2012–2015 (P = 0.037). Imipenem resistance prevalence was higher in ESBL-negative bacteria than ESBL-positive bacteria for both E. coli and K. pneumonia (P < 0.001). In Enterococcus, significant increase in resistance to ampicillin (P = 0.01) and moxifloxacin (P = 0.02) over time were observed. In Staphylococcus and fungi, rates of antibiotic resistance did not significantly change over the study period.ConclusionsGram-negative bacteria predominated as causative agents of intra-abdominal infections in GI fistula patients, and there was an increase in levels of resistance to certain antibiotics, particularly carbapenems. Infection control and source control are important tools available to surgeons to prevent the emergence of antibiotic-resistant pathogens.

BackgroundContinuous 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.MethodsWe 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.ResultsOut 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).ConclusionThe 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."

Antimicrobial susceptibility of Gram-positive cocci isolated from patients with conjunctivitis and keratitis in Crete, Greece

Urinary tract infections (UTIs) are among the most prevalent infectious diseases in older women, especially those over 65 years of age. Physiological changes related to aging, comorbidities, and frequent use of medical devices such as urinary catheters increase susceptibility. Increasing antimicrobial resistance further complicates treatment strategies. This study aims to describe the epidemiological profile of UTI in women over 65 years of age, focusing on the characterization of etiological agents, observed antimicrobial resistance patterns, and commonly reported risk factors. We conducted a retrospective analysis of microbiological and clinical data from elderly women diagnosed with UTIs. Bacterial isolates were identified and antimicrobial susceptibility profiles were evaluated over a specified period. A statistical analysis was performed to determine the prevalence of different pathogens and antibiotic resistance trends. Escherichia coli was the predominant uropathogen, consistent across different clinical scenarios and patient conditions. The four most common bacterial strains—E. coli, Klebsiella pneumoniae, Proteus mirabilis, and Enterococcus faecalis—aligned with global epidemiological data. In Escherichia coli a significant increase in resistance to nitrofurantoin was observed, possibly indicating excessive empirical use, while resistance to other antibiotics, such as amoxicillin/clavulanic acid and ertapenem, remained stable or decreased. Institutional antibiotic stewardship programs likely contributed to this trend. The study highlights E. coli as the main etiological agent in elderly women with UTIs. The observed resistance patterns emphasize the need for localized antimicrobial surveillance and personalized therapeutic approaches. Continuous microbiological monitoring and rational use of antibiotics are crucial to optimize treatment outcomes and control the development of resistance.

First-line anti-tuberculosis drug resistance patterns and trends at the national TB referral center in Iran—eight years of surveillance

Introduction: Bacterial resistance is a global phenomenon, but it presents geographic and temporal variations; this is the importance of local surveillance programs.Objective: To determine trends in antibiotic resistance in hospitals between 2007 and 2012 in Medellín and its Metropolitan Area.Materials and methods: Percentages of antibiotic resistance between 2007 and 2012 in 22 institutions were obtained using WHONET 5.6 program. For interpretation of susceptibility results, CLSI standardsof 2009 and 2012 were used. Using the Epi-Info 6.04 program a trends analysis of antibiotic resistance was done using the chi-square for linear trend with a confidence level of 95%, a value of p≤0.05 was considered significant.Results: In six years of surveillance of antibiotic resistance we found a decrease of oxacillin resistance in Staphylococcus aureus (p=0.0006) and an increase of vancomycin resistance in Enterococcus faecium (p=0.0000). In Escherichia coli and Serratia marcescens an increase of resistance to ceftazidime was found, in contrast to a decrease in Klebsiella pneumoniae (p=0.0000) and Enterobacter cloacae (p=0.058). K. pneumoniae, S. marcescens and E. cloacae showed an increase of carbapenem resistance in contrast to a reduction of carbapenem resistance in Pseudomonas aeruginosa and Acinetobacter baumannii.Conclusions: The resistance surveillance identified important findings as the emergence of E. faecium resistant to vancomycin and carbapenem-resistant Enterobacteriaceae. It is essential to determine the antibiotic use in the region to establish their influence on the resistance profiles, as well as ensuring the quality of information and microbiological procedures in the microbiology laboratories.

A comparison of antimicrobial susceptibility data of species of the Bacteroides fragilis group for 1989-1990 and 1998-1999 studies showed statistically significant increases or decreases in in vitro activity. Overall significant increases in resistance were noted for ampicillin-sulbactam and clindamycin, while significant decreases in resistance were noted for ertapenem and cefoxitin. Susceptibilities to piperacillin-tazobactam, imipenem, meropenem, and trovafloxacin remained virtually the same for the two studies. Importantly, a change in the rates of isolation of the various species showed the B. fragilis species comprised 58% of the isolates in 1989 to 1990 and 45% of the isolates in 1998 to 1999. This change in rates of isolation of B. fragilis versus non-B. fragilis species had an overall effect on susceptibility data.

Urinary tract infections (UTIs) represent a common pathology among female patients, leading to overprescribing antibiotics, globally. The emergence of the COVID-19 pandemic has dramatically increased the incidence of this particular viral pneumonia with secondary bacterial superinfection, resulting in continuous therapeutic or prophylactic recommendations of antibiotic treatment; thus, an updated analysis of current antimicrobial resistance among uropathogens is mandatory. This cross-sectional retrospective study conducted in two university hospitals in Bucharest, Romania analyzed 2469 positive urine cultures, among two different periods of 6 months, before and during the COVID-19 pandemic. The most common pathogen was Escherichia coli 1505 (60.95%), followed by Klebsiella spp. 426 (17.25%). Enterococcus spp. was the leading Gram-positive pathogen 285 (11.54%). In gram negative bacteria, in almost all cases, an increased in resistance was observed, but the highest increase was represented by quinolones in Klebsiella spp., from 16.87% to 35.51% and Pseudomonas from 30.3% to 77.41%; a significant increase in resistance was also observed for carbapenems. Surprisingly, a decrease in resistance to Penicillin was observed in Enterococcus spp., but the overall tendency of increased resistance is also maintained for gram positive pathogens. The lack of data on the influence of the COVID-19 pandemic on uropathogens’ resistance promotes these findings as important for every clinician treating UTIs and for every specialist in the medical field in promoting reasonable recommendations of antibiotic therapies.

Intestinal inflammation is associated with systemic translocation of commensal antigens and the consequent activation of B and T lymphocytes. The long-term consequences of such immune activation are not completely understood. C57BL/6 mice were subjected to 2 courses of treatment with dextran sulfate sodium (DSS) to induce colitis. Two to 7 weeks after the DSS treatment, the mice were infected intraperitoneally with Salmonella enterica serovar Typhimurium. The outcome of infection was evaluated based on survival and tissue pathogen burden. Mice that had recovered from DSS colitis displayed a significant increase in resistance to S. Typhimurium infection as indicated by improved survival and decreased tissue pathogen numbers. The colitis-induced increase in resistance to systemic salmonellosis lasted for as long as 7 weeks after discontinuing DSS and was dependent on T lymphocytes but not on B cells. Interestingly, depletion of CD4 and CD8 T cells just before the Salmonella infection did not alter the colitis-induced increase in resistance. Mice that had recovered from colitis had evidence of persistent activation of resident peritoneal macrophages and enhanced Salmonella-induced neutrophil recruitment to the peritoneum. Macrophage depletion with clodronate liposomes abrogated the colitis-induced increase in resistance to Salmonella. Taken together, our results indicate that DSS colitis leads to a long-lasting increase in resistance to Salmonella infection that is initiated in a T cell-dependent manner but is ultimately mediated independently of B and T cells as a result of persistent changes in innate immune cell function.

Post-neurosurgical nosocomial bacterial meningitis in adults: microbiology, clinical features, and outcomes