Changes In Resistance Patterns Research Articles

Detection of Macrolide and/or Fluoroquinolone Resistance Genes in Mycoplasma genitalium Strains Isolated from Men in the Northwest Region of Croatia in 2018-2023.

Mycoplasma genitalium (M. genitalium) poses a significant public health challenge due to its association with non-gonococcal urethritis (particularly in men) and antimicrobial resistance. However, despite the prevalence of M. genitalium infections and the rise in resistance rates, routine testing and surveillance remain limited. This is the first study from Croatia that aimed to assess the prevalence and trends of resistance in M. genitalium strains isolated from male individuals by detecting macrolide and fluoroquinolone resistance genes. The study also aimed to explore the factors associated with resistance and changes in resistance patterns over time. Urine samples collected from male individuals in the Zagreb County and northwest region of Croatia between 2018 and 2023 were tested for M. genitalium with the use of molecular methods. Positive samples were subjected to DNA extraction and multiplex tandem polymerase chain reaction (MT-PCR) targeting genetic mutations associated with macrolide (23S rRNA gene) and fluoroquinolone (parC gene) resistance. Of the 8073 urine samples tested from 6480 male individuals (and following the exclusion of repeated specimens), we found that the prevalence of M. genitalium infection was 2.2%. Macrolide resistance was observed in 60.4% of strains, while fluoroquinolone resistance was found in 19.2%. Co-resistance to both antibiotics was present in 18.2% of cases. A statistically significant increase in fluoroquinolone resistance was noted over the study period (p = 0.010), but this was not evident for azithromycin resistance (p = 0.165). There were no statistically significant differences in resistance patterns between age groups, whereas re-testing of patients revealed dynamic changes in resistance profiles over time. The high burden of macrolide resistance and increasing fluoroquinolone resistance underscore the urgent need for comprehensive resistance testing and surveillance programs. The implementation of resistance-guided treatment strategies, along with enhanced access to molecular diagnostics, is pivotal for effectively managing M. genitalium infections.

Changes in the antibiotic-resistant properties of pathogenic microorganisms in patients with purulent-necrotic wounds against the background of type 2 diabetes when using a probiotic antiseptic

Antibiotic resistance remains a serious problem, leading to millions of deaths every year. The increasing prevalence of type 2 diabetes mellitus (T2DM) is contributing to the continued spread of this problem. Ukraine, like other countries, feels the consequences of this problem. Over the past ten years, the number of patients with T2DM has doubled, and diabetes is already the cause of disability and death for thousands of people. Complications of T2DM, such as diabetic foot syndrome, often require surgery and antibacterial therapy. New research shows the prospects of using probiotic antiseptics based on lactic acid bacteria of the genus Bacillus in the treatment of wounds, which may open new opportunities to combat this problem and improve treatment outcomes. Objective — to analyse changes in the antibiotic‑resistant properties of pathogenic microorganisms in patients with purulent‑necrotic wounds in type 2 diabetes mellitus. Materials and methods. The study, which was conducted at the Department of General Surgery No. 2 of Bogomolets National Medical University in Kyiv City Clinical Hospital No. 3, included 229 patients with purulent‑necrotic wounds and type II diabetes. A total of 229 patients were randomly divided into two groups, with one group receiving probiotic antiseptics and the other traditional chemical antiseptics, with subsequent analysis focusing on changes in antibiotic‑resistant properties against P. aeruginosa and K. pneumoniae. Antibiotic‑resistant properties were evaluated through microbiological examination, revealing significant changes in resistance patterns among patients treated with probiotic antiseptics compared to those using traditional chemical antiseptics, assessed using statistical methods including the Student’s t‑test and Wilcoxon W‑test. Results. When the first subgroups were compared on the first day, there was no statistically significant difference in the levels of P. aeruginosa wound contamination (p=0.671). On the seventh day, there was a statistically significant difference between contamination levels (p<0.05) and the emergence of sensitivity to reserve antibiotics (p<0.05). On the 14th day, there was a statistically significant difference between contamination levels (p<0.05) and the emergence of sensitivity to reserve antibiotics (p<0.05). Conclusions. Probiotic antiseptics have a statistically significant advantage over chemical antiseptics in terms of reducing contamination and emergence of antibiotic sensitivity in patients with purulent‑necrotic wounds in type 2 diabetes mellitus.

Examining pharmacoepidemiology of antibiotic use and resistance in first-line antibiotics: a self-controlled case series study of Escherichia coli in small companion animals

BackgroundClinicians need to prescribe antibiotics in a way that adequately treats infections, while simultaneously limiting the development of antibiotic resistance (ABR). Although there are abundant guidelines on how to best treat infections, there is less understanding of how treatment durations and antibiotic types influence the development of ABR. This study adopts a self-controlled case study (SCCS) method to relate antibiotic exposure time to subsequent changes in resistance patterns. This SCCS approach uses antibiotic exposure as a risk factor, and the development of ABR as an incidence rate ratio (IRR), which can be considered as the multiplicative change in risk for bacteria to become or maintain resistance.AimTo investigate the IRR of extensive (more than 7 antibiotic classes), revert, persistent, and directed antibiotic resistance according to the duration and type of antibiotic exposures in Escherichia coli (E. coli).Methods and materialWe use anonymized veterinary clinical data from dog and cat patients older than 6 months between 2015 and 2020. Patients were considered suitable cases if they received antibiotics and had a minimum of two urinary antibiograms within a 12-month period (the first prior to antibiotics exposure and the second from 1 week to 6 months after exposure). The first antibiogram is conducted before antibiotic exposure (case n=20).FindingsFrom 20 individuals and 42 paired antibiograms we found that the IRR = 2 for extensive drug resistance in patients who received short-course antibiotic treatment compared to longer treatments. In contrast, multi-drug resistance IRR = 2.6 for long-course compared to short-course antibiotic treatment. The ratio of E. coli isolates that reverted from resistant to sensitive was 5.4 times more likely in patients who received antibiotics for longer than 10 days.

Comprehensive Analysis of HIV-1 Integrase Resistance-Related Mutations in African Countries.

The growing emergence of non-nucleoside reverse transcriptase inhibitor (NNRTI) HIV drug resistance in sub-Saharan Africa (SSA) led to the World Health Organization (WHO) recommending, in 2018, a transition to dolutegravir (DTG) as a first-line antiretroviral therapy (ART) in SSA. The broad HIV-1 genetic diversity in SSA could shape DTG effectiveness and the pattern of drug resistance mutations (DRMs) in this region. This study evaluated HIV-1 integrase (IN) DRMs and conserved regions among published groups M, N, O, and P HIV-1 sequences spanning forty years of the HIV epidemic during the transition of DTG-based ART. Overall, we found low levels of integrase strand transfer inhibitor (INSTI)-DRMs (<1%) across HIV groups between the years 1983 and 2023; however, it was unexpected to detect DRMs at statistically significantly higher frequencies in pre-INSTI (1983-2007) than in the INSTI (2008-2023) era. The variability of accessory INSTI-DRMs depended on the HIV subtypes, with implications for susceptibility to DTG. Our findings provide new perspectives on the molecular epidemiology and drug resistance profiles of INSTIs in SSA, emphasizing the need for ongoing surveillance and customized treatment approaches to address the continent's varied HIV subtypes and changing resistance patterns.

Elizabethkingia meningoseptica: Changing anti microbial resistance causing fatal community-acquired neonatal meningitis – An area of rising concern

Elizabethkingia meningoseptica is often reported as a hospital-acquired infection. We present an unusual fatal case of community-acquired meningitis probably secondary to contamination of the breast pump and feeding bottle used at home. Despite being a Gram-negative bacillus, it is extremely sensitive to antibiotics used to treat Gram-positive infections. There is a lack of protocolized effective treatment regimens and the organism demonstrates in vitro resistance to many antibiotics but a changing pattern of resistance as seen in our case is not reported till date. E. meningoseptica is an emerging potential source of neonatal infection and is an upcoming public health problem.

SG-APSIC1096: Changes in resistance patterns of “ESKAPE” pathogens to azithromincin and levofloxacin in Yogyakarta

Objectives: Bacterial coinfection occurred in 3.5% of COVID-19 patients, and secondary bacterial infection occurred in 14.3% of patients. In Indonesia, one of the guidelines for COVID-19 therapy is to administer azithromycin 500 mg per 24 hours for mild and moderate cases and azithromycin 500 mg per 24 hours and levofloxacin 750 g per 24 hours for severe cases with suspected secondary bacterial infection. At the beginning of the pandemic, many antibiotics were used, even without proven or suspected bacterial infection. We sought to determine changes in the resistance of “ESKAPE” bacteria (ie, Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp) to the antibiotics levofloxacin and azithromycin prior to and during the COVID-19 pandemic. Methods: The study was conducted retrospectively by examining the culture and sensitivity test results of “ESKAPE” bacteria to levofloxacin and azithromycin antibiotics in 2019 (before the pandemic) and April 2020–April 2021 (during the pandemic) in 4 hospitals in Yogyakarta. The number of samples represents all cultures completed within the specified period to detect antibiotic sensitivity patterns. Results: In a top referral hospital, resistance to levofloxacin and azithromycin increased significantly for E. faecium and P. aeruginosa, but at a private hospital, an increase in resistance to azithromycin and levofloxacin occurred for A. baumannii and for Enterobacter spp and resistance to levofloxacin increased significantly. At an academic hospital, there was a considerable decrease in S. aureus and E. faecium resistance to levofloxacin and azithromycin. At the government hospital, S. aureus, K. pneumoniae, P. aeruginosa, Acinetobacter baumannii, and Enterobacter spp developed resistance to levofloxacin. Conclusions: Resistance to azithromycin and levofloxacin by different ESKAPE bacteria increased on average during the COVID-19 pandemic.

Distribution of Virulence Genes in Campylobacter spp. Isolated from Agaricus Mushrooms in Iran.

The white button mushroom (Agaricus) is a significant nutritional and therapeutic species utilized in the human diet and could transmit various bacterial infections. Campylobacter species are the most common cause of foodborne illness across the world. The present study has been planned to determine the frequency of virulence genes and antibiotic susceptibility test in Campylobacter spp. recovered from Agaricus mushroom. In this study, 740 Agaricus mushroom samples were gathered randomly from various markets from June 2020 to December 2020. Confirmation of Campylobacter spp. using biochemical analyses and 23S rRNA-based PCR was performed. The agar dilution technique was used to determine resistance to antibiotics using gentamicin (GM10μg), ciprofloxacin (CIP5μg), nalidixic acid (NA30μg), tetracycline (TE30μg), ampicillin (AM10μg), amoxicillin+ clavulanic acid (AMC30μg), erythromycine (E15μg), azithromycin (AZM15μg), clindamycin (CC2μg), and chloramphenicol (C30μg). Multiplex PCR was utilized to determine the prevalence of the recR, dnaJ, wlaN, virBll, cdtC, cdtB, cdtA, flaA, cadF, pidA, ciaB, ceuE, and cgtB genes. Campylobacter spp. were detected in 74 out of 740 Agaricus mushroom samples (10%). According to the data, Agaricus mushroom samples included 32 (4.32%) C. jejuni, 11 (1.48%) C. coli, and 31 (4.18%) other Campylobacter spp. Antimicrobial resistance was most common in C. jejuni isolates. C. jejuni isolates also had the lowest resistance rate to gentamycin, ciprofloxacin, and nalidixic acid. C. coli isolates were reported to have the highest antimicrobial resistance to ciprofloxacin, ampicillin, and erythromycine. Resistance to gentamycin and amoxicillin+ clavulanic acid was likewise lowest among C. coli strains. The flaA and ciaB genes were found in 100% of B-lactams-susceptible C. jejuni and C. coli strains. When examining the relationship between antibiotic resistance and the existence of virulence genes, it was observed that there is a statistically significant relationship (p < 0.001) between bacterial resistance and virulence genes. Our findings indicated that changes in resistance patterns in Campylobacter strains have emerged from multiple treatment approaches in Agaricus mushrooms.

Changing trend in the clinico- bacteriological profile of diabetic foot infection over a decade: observations from a tertiary care hospital of India

BACKGROUND: Diabetic foot infection (DFI) is a major challenge in podiatric surgery. Initiation of an appropriate antimicrobial drug is the determining factor in the prognosis in DFI.AIM: This study was undertaken to analyse the changing trends in the clinical profile of patients and the bacterial profile causing DFI for over a decade.MATERIALS AND METHODS: This was a retrospective observational study conducted at the department of microbiology and surgery of the tertiary teaching hospital. The clinical and bacterial profile of patients with DFI in 2009 and 2019 was collected and analysed for the changing trend.RESULTS: Amongst the 203 patients (95 in 2009 and 108 in 2019) included in the study, 113 (56%) were male patients. There was a shift in the age group of patients from 51–60 to 61–70 years over a decade. There was a change of most common pathogens from Pseudomonas aeruginosa to Klebsiella species. The resistance rates to third-generation cephalosporins decreased amongst the Gram-negative isolates such as P. aeruginosa and Escherichia coli, but an increase in resistance to carbapenems was observed during the study period. There was reduced incidence of infection with methicillin-resistant Staphylococcus aureus during the study period.CONCLUSION: There was a change in the demographic and bacteriological flora in the DFI patients over a decade. The antimicrobial resistance rate varied for various antimicrobial agents over a decade for a particular pathogen. Regular surveillance of the change in resistance pattern amongst the pathogens is essential for the initiation of appropriate empirical therapy to reduce the morbidity in DFI.

Impact of Discontinuing Levofloxacin Prophylaxis on Bloodstream Infections in Neutropenic Hematopoietic Stem Cell Transplantation Patients.

Multidrug-resistant pathogens have emerged worldwide. We have driven the hypothesis that the non-use of fluoroquinolone prophylaxis during neutropenia could reduce antibiotic resistance in Gram-negative bacteria that cause bloodstream infections (BSIs) in hematopoietic stem cell transplantation (HSCT) patients and that this change in resistance pattern could lead to an impact on BSI mortality. This is a quasi-experimental study comparing BSI incidence, resistance patterns of bacteria that cause BSI, and BSI mortality when levofloxacin prophylaxis was routine for neutropenic HSCT patients (2016–2018) to when fluoroquinolone prophylaxis was discontinued in our center (2019). Bivariate comparisons and multivariate logistic regression models were used for analyses. A total of 310 HSCTs (66 (21%) allogeneic and 244 (79%) autologous) were performed during the study period. Sixty (19%) patients had BSIs, 30 in each evaluated period. The discontinuation of levofloxacin prophylaxis was associated with an increase in BSI incidence and a decrease in the resistance rates of causative BSI bacteria and in BSI 30-day mortality. The increase in the rate of resistant bacteria causing BSI and in BSI mortality might outweigh the benefits of a decrease in BSI incidence caused by fluoroquinolone prophylaxis in neutropenic HSCT patients. We suggest that the routine use of fluoroquinolone in this context be revisited.

A Review Paper on Helicobacter Pylori

Abstract: Helicobacter pylori (H. pylori) infection is a primary cause of gastroduodenal ulcer disease, gastric cancer, and a variety of other gastric and extra gastric diseases. The medical management of H. pylori is a dynamic process that requires frequent reconsideration due to changing epidemiologic conditions (e.g., immigration), changing resistance patterns with therapeutic implications, and new understanding relating to the reasons for pathogen eradication. Keywords: helicobacter pylori, pathogenic infection, gastric cancer.

Changes in resistance pattern of ESKAPE pathogens between 2010 and 2020 in the clinical center of University of Szeged, Hungary.

The acronym ESKAPE stands for six antibiotic-resistant bacterial pathogens namely, Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp. Monitoring their resistance is an important task for clinical microbiology laboratories. Our aim was to analyze the resistance patterns of these bacteria over ten years in clinical samples of our department. We examined the sample types from which these pathogens were most frequently isolated. The incidence of tests with resistant results for each pathogen in aggregate and the most important subgroups of each was also analyzed. We have also intended to predict the local priorities amongst these pathogens. The results of 1,268,126 antibiotic susceptibility tests performed on a total of 70,099 isolates over this period were examined. Most strains were derived from urine, blood culture, trachea, vagina, wounds, and abscesses. Prevalence of ESKAPE bacteria increased between 2011 and 2020 however, the steepest intensifications were seen in the cases of K. pneumoniae and P. aeruginosa. The number of antibiotic susceptibility tests with resistant results has also increased over the decade but the most notable increase was detected in E. faecium and A. baumannii. Based on the calculation of antimicrobial resistance index for each pathogen, the most serious challenges for us at present are A. baumannii, P. aeruginosa, and E. faecium and their multi-resistant forms. The theoretical prediction of proportion of resistant tests between 2020 and 2030 in our care area draws attention to a worrying trend in the cases of vancomycin-resistant E. faecium and carbapenem-resistant A. baumannii strains.

Antibiotic resistance among clinical Ureaplasma isolates from Cuban individuals between 2013 and 2018.

Introduction. Acquired resistance against the antibiotics that are active against Ureaplasma species has been described.Hypothesis/Gap Statement. Diagnostics combined with antimicrobial sensitivity testing are required for therapeutic guidance.Aim. To report the prevalence of antimicrobial resistance among Cuban Ureaplasma isolates and the related molecular mechanisms of resistance.Methodology. Traditional broth microdilution assays were used for antimicrobial sensitivity testing in 262 clinical Ureaplasma species isolates from Cuban patients between 2013 and 2018, and a subset of samples were investigated in parallel with the commercial MYCO WELL D-ONE rapid culture diagnostic assay. The underlying molecular mechanisms for resistance were determined by PCR and sequencing for all resistant isolates.Results. Among the tested isolates, the tetracycline and erythromycin resistance rates were 1.9 and 1.5%, respectively, while fluoroquinolone resistance was not found. The tet(M) gene was found in all tetracycline-resistant isolates, but also in two tetracycline-susceptible Ureaplasma clinical isolates. We were unable to determine the underlying mechanism of erythromycin resistance. The MYCO WELL D-ONE kit overestimated tetracycline and erythromycin resistance in Ureaplasma spp. isolates.Conclusions. Although low levels of antibiotic resistance were detected in Cuban patients over a 5-year period, continued surveillance of the antibiotic susceptibility of Ureaplasma is necessary to monitor possible changes in resistance patterns.

Etiology of cervicitis: Are there new agents in play?

Considering the changing causative and resistance pattern of agents implicated in sexually transmitted infections (STIs), etiological diagnosis is imperative, especially in countries practicing syndromic management. This study was designed to identify etiological agents associated with cervicitis and to analyze their association with clinical and behavioral profile. Female STI clinic attendees presenting with cervico-vaginal discharge were examined for the presence of cervicitis. Endocervical swabs were collected for gram staining and real-time polymerase chain reaction was performed for various bacterial and viral STI agents in patients presenting with cervical discharge. A vaginal swab was also evaluated for bacterial vaginosis by Nugent's criteria. Of 64 patients with vaginal discharge, 26.6% and 12.5% patients complained of genital itching and lower abdominal pain, respectively. Mean of 36.6 pus cells/hpf were observed, appreciably greater number in patients with Neisseria gonorrhoeae and Chlamydia trachomatis infections (P = 0.0063 and 0.0032, respectively). Pus cells were high (mean 68 pus cells/hpf) in patients with Ureaplasma urealyticum, though this may be attributed to coexisting N. gonorrhoeae. Agents isolated from endocervix were N. gonorrhoeae, 17 (26.6%), Trichomonas vaginalis, 4 (6.3%), HSV1 and C. trachomatis, 1 each (1.6%), HSV2, 9 (14.1%), U. urealyticum 5 (7.8%), Ureaplasma parvum 26 (40.6%), Mycoplasma genitalium (0%), and Mycoplasma hominis 11 (17.2%). Bacterial vaginosis was diagnosed in 14 (21.9%) patients. Multiple agents were isolated in 10 (two), 6 (three), 6 (four), and 1 (five) patients. Isolation of M. hominis and U. parvum was significantly associated with bacterial vaginosis (P = 0.04 and 0.003, respectively). Nonusage of condoms and mental stress predisposed to cervicitis. We concluded that there are changing etiological patterns of cervicitis. There is need to use tests that detect wider array of organisms, and can replace standard culture methods with molecular assays, to increase the ability to diagnose more number of organisms implicated in cervicitis.

Patterns of methicillin-resistant Staphylococcus aureus (MRSA) strains isolated at a tertiary care hospital

Background: The current study was aimed to investigate the patterns of Methicillin-resistant Staphylococcus aureus (MRSA) isolates and their antibiotic susceptibility in Oman with a special focus on determining the changing resistance patterns. Materials and Methods: The current study was a retrospective cross-sectional study, conducted at a referral hospital in Oman. The socio-demographic characteristics and the microbiological data of MRSA strains isolated between January 2015 and December 2018 were reviewed. Descriptive statistics were presented as frequencies and percentages. Results: In total, 1190 MRSA isolates from clinical specimens were studied. Infection was predominant among males (59%). There was an increasing trend of MRSA infection (19.2%–28.5%) from 2015 to 2018. The frequency of infection was less among elderly as compared to other age groups. Majority (58.7%) of MRSA was recovered from pus and wound swabs. The overall resistance to the tested antibiotics was as follows; ciprofloxacin (30.2%), erythromycin (27.1%), clindamycin (21.8%), gentamicin (10.7%), trimethoprim-sulfamethoxazole (5.2%), linezolid (0.3%), and vancomycin (0.2%). Furthermore, a significant increase in resistance to antibiotics such as ciprofloxacin (from 16.8% to 37.1%), erythromycin (from 13.4% to 27.7%), gentamicin (5.2% to 16.1%), clindamycin (from 11.5% to 26.6%), and trimethoprim-sulfamethoxazole (from 1.8% to 7.2%) over time from 2015 to 2018 was observed. Conclusions: The present study revealed a relatively high frequency of MRSA infection and changes in their antibiotic-resistance patterns to some commonly used antibiotics over time in Sohar Hospital. Optimized antibiotic prescription through targeted stewardship interventions to preserve formulary antibiotics that still maintain their effectiveness and updating existing infection control practices is crucial.

Enhancing the empiric antibiotic selection by introducing an antibiogram toolkit in a tertiary care hospital in Southern India - A prospective study.

Antibiograms gives an overview of the cumulative susceptibility of formal antibiotics to bacterial isolates, which reflects the portion of each bacterium susceptible to a given antibiotic formulation by using antimicrobial susceptibility testing. The objective of this study is to gather and analyse data from drug utilization evaluation (DUE) studies and antimicrobial susceptibility tests in order to create an antibiogram toolkit that will help clinicians to select appropriate antimicrobial agents for initial empirical antibiotic therapy at point of care settings and avoid irrational use of antibiotics. A prospective interventional study was conducted at tertiary care hospital, biological samples of infectious patients were collected from various wards as per Clinical & Laboratory Standards Institute CLSI M39-A4guidelines. Antimicrobial susceptibility results were analysed using WHONET software. Antibiotic stewardship committee was formed and involved in monitoring the usage of antibiotics, measuring outcomes, collecting feedback and finding the scope for improving the application of antibiogram toolkit in the hospital. Antibiotic usage tracking method was followed to know the level of adherence to the prescribing guidelines by the health care professionals. A total of 157samples were obtained from various wards of the hospital. In that, Escherichia coli, Staphylococcus aureus and Klebsiella Pneumoniae were isolated in significant numbers. Antibacterial susceptibility results were collected, an initial antibiogram was developed for 18 antibacterial agents with respect to 3gram-positive (+) and 1gram-negative (-) organisms. 90% of prescribers mentioned that the antibiogram was useful, and 76% of them adhered to the guidelines. 26% were not adhered due to the patient-related factors. In our study, we have used qualitative and quantitative evaluation of drug utilization (DUE) reports to understand the existing prescribing pattern of antibiotics and setting target organisms and antibacterials to develop the hospital antibiogram. Combining DUE studies and antibiogram development was helpful in implementing effective antibiotic policies for the hospital. Further, this study pattern will be continued on a yearly basis and focused on developing cumulative antibiograms to understand the changes in resistance pattern of antimicrobials and utilization of antibiotics in the hospital.

Prevalence of Antibiotic Resistance Over Time in a Third-Level University Hospital.

This study evaluated the spread and possible changes in resistance patterns of ESKAPE bacteria to first-choice antibiotics from 2015 to 2019 at a third-level university hospital after persuasive stewardship measures were implemented. Isolates were divided into three groups (group 1, low drug-resistant; group 2, multidrug/extremely drug-resistant; and group 3, pan-resistant bacteria) and a chi-squared test (χ2) was applied to determine differences in their distributions. Among the 2,521 isolates, Klebsiella pneumoniae was the most frequently detected (31.1%). From 2015 to 2019, the frequency of isolates in groups 2 and 3 decreased from 70.1% to 48.6% (χ2 = 63.439; p < 0.0001). Stratifying isolates by bacterial species, for K. pneumoniae, the frequency of PDR isolates decreased from 20% to 1.3% (χ2 = 15.885; p = 0.003). For Acinetobacter baumannii, a statistically significant decrease was found in groups 2 and 3: from 100% to 83.3% (χ2 = 27.721; p < 0.001). Also, for Pseudomonas aeruginosa and Enterobacter spp., the frequency of groups 2 and 3 decreased from 100% to 28.3% (χ2 = 225.287; p < 0.001) and from 75% to 48.7% (χ2 = 15.408; p = 0.003), respectively. These results indicate that a program consisting of persuasive stewardship measures, which were rolled out during the time frame of our study, may be useful to control drug-resistant bacteria in a hospital setting.

Etiology and antimicrobial susceptibility profiles of anaerobic bacteria isolated from clinical samples in a university hospital in Madrid, Spain

BackgroundThe anaerobic infection management is usually based on empirical treatment because anaerobic culture techniques take a long time due to their fastidious nature. The aim of this study was to analyze the etiological profile of severe anaerobic infections and AST data from clinical anaerobic bacteria isolated in a tertiary hospital in Madrid (Spain). Material and methodsA consecutive study was carried out over 19 months in Ramón y Cajal Universitary Hospital, Madrid. Clinical samples were processed in appropriate anaerobic media and incubated using Anoxomat system. Identification was performed by MALDI-TOF. AST were determined with gradient diffusion method using EUCAST (penicillin, co-amoxiclav, imipenem, clindamycine and metronidazole) or CLSI (cefoxitin) breakpoints. ResultsDuring the period of study, 503 anaerobic microorganisms isolated from 424 clinical samples were included. Twenty-six percent of the cultures were monomicrobial, while 70.0% also contained aerobic bacteria. The most common source of infection was abscesses (26%), while blood infections represented the 11%. Anaerobic gram-negative bacilli were predominant (41%), being Bacteroides fragilis (13%) the most prevalent overall; anaerobic gram-positive bacilli represented 35%, anaerobic gram-positive cocci 19% and anaerobic gram-negative cocci 5%. Metronidazole and imipenem were the most effective agents tested against anaerobic bacteria, while clindamycin presented higher resistance rates. ConclusionAntimicrobial susceptibility surveillance of anaerobic bacteria should be performed to monitor changes in resistance patterns and to be able to optimize empiric antimicrobial treatment. Reliable species identification and quick reporting of results would guide clinicians to select the optimal antimicrobial therapy.

Changing Resistance Pattern among Gram-Negative Bacilli from Cancer Patients with Respiratory Infections at a Cancer Center

Cancer patients due to their immune-compromised nature are more prone to infections among which respiratory tract infections (RTIs) are frequently reported to account for 3 to 5% of deaths. In recent years, antibiotic resistance among respiratory pathogens is increasing emergently. The present study was conducted retrospectively at the microbiology division of a tertiary care hospital over 4 years (Jan 2016 – Dec 2019) aimed to find out the bacterial etiology of RTIs in cancer patients. Patients of all age groups, suspected of RTI recorded in microbiology registers were included in the study. During the study period, out of 2918 specimens (Jan 2016- Dec 2019) received in the microbiology lab, 2,065 (70%) specimens showed meaningful growth, whereas 269 (9%) specimens showed contaminated growth, 584 (20%) specimens showed no growth. From the 2,065 specimens, 1420 bacterial isolates were recovered. Out of the total 1420 isolates identified, 912 (64%) were gram-negative bacilli (GNB) and 508 (35.7%) were gram-positive organisms. About 19.6 % of patients were in the age group of fewer than 20 years, 54.4% in 21–60 years and 26% were of more than 60 years of age. The male-to-female ratio was 60.1:39.9. Trends of antimicrobial resistance among the leading pathogens causing RTI were studied in two phases, i.e., from 2016–2017 (phase I) and 2018–2019 (phase II). Phase I and II showed an increasing trend in resistance to cephalosporins and a declining trend in resistance to aminoglycosides (resistance to gentamicin was relatively high when compared with amikacin). In Phase I (2016 and 2017) resistance to Beta Lactams ranged from 66 to 97% and it is relatively high in phase II (2018 and 2019). But in contrast to other gram-negative isolates, Acinetobacter spp were more resistant to most groups of antibiotics during both Phases I (85–97%) and II (95–97%). Multidrug resistance (resistance to three or more than three drugs) was observed in most of the total isolates during the study period. The increasing trend of resistance in gram-negative organisms is alarming. Judicious use of older and newer antimicrobial agents is essential to prevent the emergence of multidrug-resistant bacteria. The development of newer therapeutic alternatives to address the problem of MDR GNBs is needed.

Temporal evolution of sulfadoxine-pyrimethamine resistance genotypes and genetic diversity in response to a decade of increased interventions against Plasmodium falciparum in northern Ghana

BackgroundAnti-malarial drug resistance remains a key concern for the global fight against malaria. In Ghana sulfadoxine-pyrimethamine (SP) is used for intermittent preventive treatment of malaria in pregnancy and combined with amodiaquine for Seasonal Malaria Chemoprevention (SMC) during the high malaria season. Thus, surveillance of molecular markers of SP resistance is important to guide decision-making for these interventions in Ghana.MethodsA total of 4469 samples from uncomplicated malaria patients collected from 2009 to 2018 was submitted to the Wellcome Trust Sanger Institute, UK for DNA sequencing using MiSeq. Genotypes were successfully translated into haplotypes in 2694 and 846 mono infections respectively for pfdhfr and pfdhps genes and the combined pfhdfr/pfdhps genes across all years.ResultsAt the pfdhfr locus, a consistently high (> 60%) prevalence of parasites carrying triple mutants (IRNI) were detected from 2009 to 2018. Two double mutant haplotypes (NRNI and ICNI) were found, with haplotype NRNI having a much higher prevalence (average 13.8%) than ICNI (average 3.2%) across all years. Six pfdhps haplotypes were detected. Of these, prevalence of five fluctuated in a downward trend over time from 2009 to 2018, except a pfdhps double mutant (AGKAA), which increased consistently from 2.5% in 2009 to 78.2% in 2018. Across both genes, pfdhfr/pfdhps combined triple (NRNI + AAKAA) mutants were only detected in 2009, 2014, 2015 and 2018, prevalence of which fluctuated between 3.5 and 5.5%. The combined quadruple (IRNI + AAKAA) genotype increased in prevalence from 19.3% in 2009 to 87.5% in 2011 before fluctuating downwards to 19.6% in 2018 with an average prevalence of 37.4% within the nine years. Prevalence of parasites carrying the quintuple (IRNI + AGKAA or SGEAA) mutant haplotypes, which are highly refractory to SP increased over time from 14.0% in 2009 to 89.0% in 2016 before decreasing to 78.9 and 76.6% in 2017 and 2018 respectively. Though quintuple mutants are rising in prevalence in both malaria seasons, together these combined genotypes vary significantly within season but not between seasons.ConclusionsDespite high prevalence of pfdhfr triple mutants and combined pfdhfr/pfdhps quadruple and quintuple mutants in this setting SP may still be efficacious. These findings are significant as they highlight the need to continuously monitor SP resistance, particularly using deep targeted sequencing to ascertain changing resistance patterns.

A142 TRENDS IN HELICOBACTER PYLORI TREATMENT AND CURE IN EDMONTON: 2015–2020

Abstract Background Therapies for Helicobacter pylori infection have changed significantly over time due to changes in resistance patterns. In 2016, the Toronto H. pylori consensus guidelines recommended treatment for 14 days. First-line therapies are concomitant therapy with a proton-pump inhibitor (PPI) and clarithromycin-amoxicillin-metronidazole (CLAMET) or bismuth-based quadruple therapy (PPI-bismuth-metronidazole-tetracycline, PBMT). Second and/or third line therapies are PBMT or PPI-amoxicillin-levofloxacin (PAL) and the fourth line PPI-amoxicillin-rifabutin (PAR) for 10 days. Aims To describe and compare the efficacy of current treatment regimens for H. pylori infection in Edmonton. Methods This retrospective study reviewed records of patients treated for H. pylori infection at the University of Alberta Hospital (UAH) in Edmonton, Alberta from January 1, 2015 - November 1, 2020. Diagnosis of H. pylori infection and test-of-cure were documented with a positive urea breath test, stool antigen test, histology on endoscopy, or positive culture. Patients who had no post-treatment testing were excluded. The per protocol efficacy of different regimens was calculated as well as cumulative success rates when given as 2nd, 3rd or 4th line therapy. Results Overall, 170 of 237 (71.7 %) confirmed H. pylori cases achieved cure. The majority were female (64%) and 113 (48%) were born outside of Canada. CLAMET initiated at UAH had the highest success rate 41/45 (91%), and in referred patients who were previously treated was successful as first-line therapy in 45/70 (64%). Overall success rate of regimens were as follows (Table 1): CLAMET 49/98 (50%), PBMT 45/114 (40%), PAL 33/99 (33%), and PAR 16/31 (51%). Alternative regimens were not successful 27/223 (12%). Cultures and resistance profiles were available for 53 cases that failed initial treatment. Resistance to clarithromycin (84%), metronidazole (48%), and levofloxacin (41%) was highly prevalent (Figure 1). Conclusions Test-of-cure is important to verify H. pylori eradication as antibiotic resistance is common to clarithromycin, metronidazole, and levofloxacin when prior treatments failed. These results support the H. pylori treatment regimens recommended by the Toronto consensus guidelines. Funding Agencies None