Trimethoprim-sulfamethoxazole Resistance Research Articles

Phenotypic and Genotypic Study of Staphylococcus Haemolyticus and Staphylococcus Warneri Clinically Isolated from the Bloodstream

Background: The Staphylococcus haemolyticus and Staphylococcus warneri are coagulase-negative staphylococci (CoNS) as part of human skin’s natural flora. In recent years, CoNS has increased its visibility as opportunistic pathogens acquired in hospital patients. This study aims to isolate S. haemolyticus and S. warneri strains from patients with bloodstream infections and to analyze the antimicrobial profile of these bacteria by molecular detection of the mecA gene. Materials and Methods: Four hundred and twenty-three clinical blood samples were collected from patients admitted to general three hospitals in Hilla city, Iraq, during the period from September 2021 to July 2022. Blood samples were inoculated immediately into blood bottles containing 70 ml of Brain-Heart Infusion Broth. All isolates were identified by morphology, biochemical tests, and VITEK 2 automated system (bioMerieux, France). The Congo red agar plate test was used to detect biofilm production. The mecA gene was detected by conventional polymerase chain reaction. Results: S. haem olyticus (nine isolates) and S. warneri (six isolates) were detected out of 423 clinical blood samples. Molecular detection of the mecA gene was detected in all 15 isolates. As well 11 (73.3%) isolates were β-lactam resistant and biofilm production. The results of oxacillin-resistance minimum inhibitory concentration (MIC) (≥4 mg/ml) showed that 11 (73.3%) of the 15 isolates were oxacillin and methicillin-resistant CoNS (MR-CoNS). Susceptibility to various isolates (MICs µg/ml) using VITEK 2 system showed erythromycin (≥8 µg/ml), rifampin (≥4 µg/ml), clindamycin (≥4 µg/ml), and trimethoprim-sulfamethoxazole (≥4 µg/ml) resistance were (80%), (13.3%), (20%), and (53.3%), respectively. All isolates were (100%) sensitive to linezolid (≥8 µg/ml) and teicoplanin (≥32 µg/ml). Conclusions: The S. haemolyticus and S. warneri are serious infections associated with bacteremia and septicemia infections. Linezolid, teicoplanin, and rifampin are the drug of choice for the treatment of infections caused by MR-CoNS isolates. A high rate of the mecA gene and biofilm production is present in these bacteria.

Prediction of Antibiotic Resistance in Patients With a Urinary Tract Infection: Algorithm Development and Validation.

The early prediction of antibiotic resistance in patients with a urinary tract infection (UTI) is important to guide appropriate antibiotic therapy selection. In this study, we aimed to predict antibiotic resistance in patients with a UTI. Additionally, we aimed to interpret the machine learning models we developed. The electronic medical records of patients who were admitted to Yongin Severance Hospital, South Korea were used. A total of 71 features extracted from patients' admission, diagnosis, prescription, and microbiology records were used for classification. UTI pathogens were classified as either sensitive or resistant to cephalosporin, piperacillin-tazobactam (TZP), carbapenem, trimethoprim-sulfamethoxazole (TMP-SMX), and fluoroquinolone. To analyze how each variable contributed to the machine learning model's predictions of antibiotic resistance, we used the Shapley Additive Explanations method. Finally, a prototype machine learning-based clinical decision support system was proposed to provide clinicians the resistance probabilities for each antibiotic. The data set included 3535, 737, 708, 1582, and 1365 samples for cephalosporin, TZP, TMP-SMX, fluoroquinolone, and carbapenem resistance prediction models, respectively. The area under the receiver operating characteristic curve values of the random forest models were 0.777 (95% CI 0.775-0.779), 0.864 (95% CI 0.862-0.867), 0.877 (95% CI 0.874-0.880), 0.881 (95% CI 0.879-0.882), and 0.884 (95% CI 0.884-0.885) in the training set and 0.638 (95% CI 0.635-0.642), 0.630 (95% CI 0.626-0.634), 0.665 (95% CI 0.659-0.671), 0.670 (95% CI 0.666-0.673), and 0.721 (95% CI 0.718-0.724) in the test set for predicting resistance to cephalosporin, TZP, carbapenem, TMP-SMX, and fluoroquinolone, respectively. The number of previous visits, first culture after admission, chronic lower respiratory diseases, administration of drugs before infection, and exposure time to these drugs were found to be important variables for predicting antibiotic resistance. The study results demonstrated the potential of machine learning to predict antibiotic resistance in patients with a UTI. Machine learning can assist clinicians in making decisions regarding the selection of appropriate antibiotic therapy in patients with a UTI.

Local Antimicrobial Resistance Trends in Pediatric Urinary Tract Infection: The Importance of Local Surveillance of a Global Problem.

Introduction Urinary tract infections (UTIs) are one of the most common pediatric bacterial infections and consequently a major reason for antibiotic treatment. Despite being a global problem, antimicrobial resistance is often geographically heterogeneous. Thus, it is fundamental to know local epidemiology and practice frequent surveillance of each hospital's antibiograms. The aims of this study areto determine the local antimicrobial resistance profile in pediatric UTIs, to understand its evolution over 14 years, and finally, to infer if the currently instituted antibiotic empirical therapy remains effective. Materials and methods A retrospective observational study was performed through the analysis of urine cultures and respective antibiograms of children diagnosed with UTIfrom 2017 to 2019 in Centro Hospitalar Universitário do Algarve (Faro's unit, Portugal), followed by a comparison of the obtained datawith the results of a similar study performed between 2003 and 2005. Results A total of 784 urine cultures were selected. Escherichia coli was the most frequent microorganism (n = 561; 71.56%), followed by Proteus mirabilis (n = 117; 14.92%) and Klebsiella pneumoniae (n = 40; 5.10%). The most commonly prescribed antibiotic was cefuroxime axetil (66.28%). Escherichia coli had an increase in resistance to amoxicillin-clavulanate of 6.16% to 34.76% and cefuroxime axetil of 0.73% to 4.46%. Proteus mirabilis had an increase in resistance to amoxicillin-clavulanate of 1.64% to 11.11%. Klebsiella pneumoniae had an increase in resistance to cefuroxime axetil (0%-27.50%) and nitrofurantoin (0%-47.50%). The three microorganisms showed a decrease in trimethoprim-sulfamethoxazole resistance profiles, as well as low resistance profiles to fosfomycin. In fifty cases in which antibiotic empirical therapy was instituted, the isolated microorganism revealed in vitro resistance; 37 of these cases had a good evolution, maintaining the antibiotic empirical therapy. Discussion Local surveillance of antimicrobial resistanceallows monitoring of the resistance trends and adequacy of empirical antibiotic therapy. This study's local resistance profile was distinct from other regions of the country and the world. Continuous local surveillance also potentiates the dissemination of the results to the concerned healthcare providers and the initiation of timely responsive measures, containing the increase in antimicrobial resistance. As Escherichia coli was the commonest isolated microorganism, its antimicrobial profile should dictate antibiotic empirical therapy. This study supports that in vitro is not equivalent to in vivo resistance. Conclusion There was a significant increase in antimicrobial resistance profiles, especially to amoxicillin-clavulanate. Cefuroxime axetil remains the recommended antibiotic for empirical therapy in this hospital, although fosfomycin should be considered as an alternative in non-complicated cystitis in adolescent females. This study reinforces the importance of continuous local resistance surveillance as a preventive measure against the global increase in antimicrobial resistance.

Clinical characteristics and bacterial culture in complicated appendicitis at Hue University of Medicine and Pharmacy Hospital

Objectives: To evaluate the clinical, laboratory features, bacterial culture outcomes, and antibiotic susceptibilities of these bacteria in intraoperative samples from patients with perforated appendicitis and to establish whether they influence postoperative outcomes. Materials and methods: A descriptive study was conducted on 68 laparoscopic surgery patients from June 2022 to March 2023 at the Digestive Surgery Department, Hue University of Medicine and Pharmacy Hospital. Results: The male/female ratio is 1.2. The mean age was 37.5 ± 25.7. The mean time of the symptom onset was 37.2 ± 29.1 hours; CRP increased in 86.8% of cases. The average postoperative hospital stay was 6.3 ± 2.2 days; Postoperative complications were observed in 20.6%. Peritoneal fluid samples yielded a positive culture in 58 (85.3%); Gram-negative bacteria were isolated in 89.7%; gram-positive bacteria were isolated in 10.3%; polymicrobial growth was observed in 29.4% of the patients. E. coli in 67.6%, P.aeruginosa in 10.3%, Enterobacter spp. in 8.8%, Klebsiella spp. in 4.4%, Citrobacter spp. in 3%; positive ESBL was present in 17 (37%) of the 46 E. coli strains, ESBL was positivity detected in one of Morganerlla morganii strains. In E. coli, ampicillin resistance was 88.6%, amoxicillin-clavulanic acid resistance was 61.5%, and Trimethoprim-sulfamethoxazole resistance was 65%. Conclusion: It is necessary to choose treatment regimens based on local bacteriology and resistance status to optimize empiric empirical postoperative antibiotic regimens. Key words: perforated appendicitis, ESBL, complications, bacteria culture.

Clinical significance of mutations in dihydropteroate synthase in Pneumocystis jirovecii pneumonia among non-HIV-infected patients

BackgroundDihydropteroate synthase (DHPS) mutations may be associated with trimethoprim-sulfamethoxazole resistance in Pneumocystis jirovecii pneumonia (PCP) and worse clinical outcomes. However, the clinical significance of DHPS mutations in PCP among non-human immunodeficiency virus (HIV)-infected patients remains unclear. MethodsPatients with PCP in three tertiary referral hospitals in Taiwan between 2016 and 2020 were retrospectively enrolled. Two point mutations, Thr55Ala and Pro57Ser, in the DHPS protein were analysed. Patients with invalid DHPS mutations in the respiratory specimen, chronic respiratory failure, receiving endotracheal intubation for surgical intervention, HIV infection, Pneumocystis jirovecii colonisation, and no lactate dehydrogenase (LDH) data were excluded. The primary outcome was 30-day survival. ResultsA total of 215 patients were analysed. Mutants inside DHPS were found in 78 patients (36.3%) and 68 patients (31.6%) died within 30 days. A total of 214 patients (99.5%) received trimethoprim-sulfamethoxazole as the first-line treatment. The rates of mechanical ventilation, 30-day, and in-hospital mortality were similar between wild-type and mutant DHPS PCP. After adjusting for important confounders, LDH > 500 µ/L (adjusted hazard ratio [aHR] = 2.448, P = 0.001), pneumonia severity index > 135 mg/dL (aHR = 1.689, P = 0.049), and having solid tumours (aHR = 1.832, P = 0.034) were independently associated with higher mortality. In subgroup analysis, mutant DHPS PCP patients had less 30-day mortality among patients aged > 65 years (P = 0.049), with lymphopenia (P = 0.040), and those without solid tumour (P = 0.045). ConclusionsIn non-HIV-infected PCP, point mutants inside DHPS may not be associated with trimethoprim-sulfamethoxazole treatment outcomes. Further prospective large-scale studies are warranted.

Application of Precision Medicine Concepts in Ambulatory Antibiotic Management of Acute Pyelonephritis.

Acute pyelonephritis (APN) is a relatively common community-acquired infection, particularly in women. The early appropriate antibiotic treatment of this potentially life-threatening infection is associated with improved outcomes. The international management guidelines for complicated urinary tract infections and APN recommend using oral antibiotics with <10% resistance among urinary pathogens. However, increasing antibiotic resistance rates among Escherichia coli and other Enterobacterales to fluoroquinolones, trimethoprim-sulfamethoxazole (TMP-SMX), and beta-lactams has left patients without reliable oral antibiotic treatment options for APN. This narrative review proposes using precision medicine concepts to improve empirical antibiotic therapy for APN in ambulatory settings. Whereas resistance rates to a particular antibiotic class may exceed 10% at the population-based level, the predicted antibiotic resistance rates based on patient-specific risk factors fall under 10% in many patients with APN on the individual level. The utilization of clinical tools for the prediction of fluoroquinolones, TMP-SMX, and third-generation cephalosporin resistance improves the ambulatory antibiotic management of APN. It may also reduce the need to switch antibiotic therapy later based on the in vitro antibiotic susceptibility testing results of bacterial isolates in urinary cultures. This approach may mitigate the burden of increasing antibiotic resistance in the community by ensuring that the initial antibiotic prescribed has the highest likelihood of treating APN appropriately.

Urinary Tract Infections in Children: Clinical and Antibiotic Susceptibility Data from a Tertiary Care Hospital

Aim: Urinary tract infections (UTIs) are among the most common bacterial infections in children.&#x0D; Empirical antibiotic treatment is recommended until the antibiogram reports of urine culture are&#x0D; available. It is essential to initiate local UTI agents and their antimicrobial susceptibility patterns in&#x0D; specific geographical regions to choose the best empirical antibiotics. The current study aimed to&#x0D; determine causative microorganisms and antibiotic resistance patterns in children diagnosed with UTI.&#x0D; Material and Methods: The study was carried out retrospectively with 216 children diagnosed with&#x0D; UTIs for the first time. The patients were categorized into two groups according to age (≤1 year and &gt;1&#x0D; year). Demographic data, presenting symptoms, imaging findings, and urine and culture analysis results&#x0D; were collected and compared between these two groups.&#x0D; Results: Cefazolin and nitrofurantoin use may be preferred in the empirical treatment of UTIs caused&#x0D; by Escherichia coli and Enterococcus spp. Additionally, amoxicillin/clavulanate was recommended in&#x0D; the empirical therapy of UTIs caused by Enterococcus spp., Klebsiella spp., and Proteus spp. The&#x0D; trimethoprim-sulfamethoxazole and nitrofurantoin resistance of E. coli was found to be statistically&#x0D; significantly higher in the ≤1 year group (p=0.03 and p=0.01, respectively), while the nitrofurantoin&#x0D; resistance of Klebsiella was statistically significantly higher in the &gt;1 year group (p=0.01). The gentamicin&#x0D; resistance of Klebsiella spp. was statistically significantly higher in the ≤1 year group (p=0.03).&#x0D; Conclusion: It is important to detect regional antibiotic resistance patterns to manage UTIs and minimize&#x0D; related complications. Antibiotic susceptibility studies are necessary to reduce improper antibiotic use&#x0D; and resistance rates of antibiotics.

The Relationship between the Biofilm Genes and Antibiotic Resistance in Stenotrophomonas maltophilia.

Today, Stenotrophomonas maltophilia (S. maltophilia) is a major opportunistic pathogen among hospitalized or immunocompromised patients. Antibiotic-resistant clinical isolates are increasing in several parts of the world. Various antibiotic-resistance and biofilm-forming genes are identified in this bacterium. Its capacity to form biofilms is an important virulence factor that may impact antibiotic-resistance patterns. In the current study, we evaluated the biofilm-formation capacity, antibiotic-resistance profile, and prevalence of biofilm-forming genes as well as antibiotic resistance genes among S. maltophilia isolates. In this cross-sectional study, 94 clinical S. maltophilia isolates were recovered from four tertiary-care hospitals in Iran between 2021 and 2022. The presence of the selected antibiotic-resistance genes and biofilm-forming genes was examined by polymerase chain reaction (PCR). The ability of biofilm formation was examined by microtiter plate assay. The Kirby-Bauer disc diffusion method was used to evaluate the trimethoprim-sulfamethoxazole (TMP-SMX), levofloxacin, and minocycline resistance. S. maltophilia is mainly isolated from bloodstream infections. Notably, 98.93% of isolates were biofilm producers, of which 19.35%, 60.22%, and 20.43% produced strong, moderate, and weak biofilm, respectively. The frequency of biofilm genes was 100%, 97.88%, 96.80%, and 75.53% for spgM, rmlA, smf-1, and rpfF, respectively. Isolates with the genotype of smf-1+/rmlA+/spgM+/rpfF+ were mostly strong biofilm producers. Among the antibiotic-resistance genes, the Smqnr, L1, and sul1 had the highest prevalence (76.59%, 72.34%, and 64.89), respectively. Antimicrobial susceptibility evaluation showed 1.06%, 3.19%, and 6.3% resistance to minocycline, TMP-SMX, and levofloxacin. The results of the current study demonstrated that S. maltophilia isolates differ in biofilm-forming ability. Moreover, smf-1, rmlA, and spgM genes were presented in all strong biofilm producers. Although the overall resistance rate to the evaluated antibiotics was high, there was no statistically significant relation between antibiotic resistance and the type of biofilm.

Relationship between antibiotic resistance with class 1 integron and SmeDEF efflux pump encoding genes in clinical isolates of Stenotrophomonas maltophilia.

Stenotrophomonas maltophilia is an emerging multidrug-resistant organism with an increasing frequency of hospital-acquired infections predominantly in developing countries. The purpose of this study was to determine the antibiotic resistance and frequency of the smeD, class 1 integron, and sul1 genes in clinical isolates of S. maltophilia in two Iranian provinces. From January 2020 to September 2021, 38 clinical isolates of S. maltophilia were collected from patients in hospitals in Tabriz and Sanandaj provinces of Iran. S. maltophilia isolates were confirmed by standard bacteriological tests and 16S rRNA gene PCR. Disk diffusion and the MIC test strip methods were used to determine the antibiotic resistance patterns. PCR was performed to investigate the presence of smeD, class 1 integron, and sul1 genes. The antimicrobial test for the isolated S. maltophilia showed a high level of sensitivity against most of the antibiotics used. Maximum sensitivity was recorded for ciprofloxacin (100% (38/38)) and levofloxacin 100% (38/38), followed by ceftazidime (97.36% (37/38)), trimethoprim-sulfamethoxazole (81.57% (31/38)), ticarcillin-clavulanate (60.52% (23/38)), and piperacillin-tazobactam (55.26% (21/38)). We observed a high prevalence of smeD (100% (38/38)) and class 1 integron (94.73% (36/38)) genes in the isolates, and none of the isolates carried the sul1 gene. The findings from this study indicate that resistance to trimethoprim-sulfamethoxazole was not observed, and still, trimethoprim-sulfamethoxazole is the best drug with desirable antimicrobial effect in the treatment of nosocomial infections caused by S. maltophilia strains. Despite the observation of a high number of class 1 integron, the sul1 gene was not observed, which indicates the role of this gene in high-level trimethoprim-sulfamethoxazole resistance and not having a role in low-level resistance. Based on our results, clinical microbiology laboratories need continuous surveillance of resistance rates to trimethoprim-sulfamethoxazole, because of the possibility of S. maltophilia acquiring trimethoprim-sulfamethoxazole-resistance by mobile gen elements.

Molecular characterization of multidrug-resistant non-typeable Haemophilus influenzae with high-level resistance to cefuroxime, levofloxacin, and trimethoprim-sulfamethoxazole

BackgroundNon-typeable Haemophilus influenzae (NTHi) has become the major cause of invasive H. influenzae diseases in the post-H. influenzae type b vaccine era. The emergence of multidrug-resistant (MDR) NTHi is a growing public health problem. Herein, we investigated the molecular basis of MDR in NTHi. The isolated NTHi were subjected to antimicrobial susceptibility testing for 12 agents. Whole genome and plasmid sequencing were conducted and analyzed to identify significant genetic variations and plasmid-encoded genes conferred antibiotic resistance.ResultsThirteen (50%) MDR NTHi isolates were obtained; of these, 92.3% were non-susceptible to ampicillin, 30.8% to amoxicillin-clavulanate, 61.5% to cefuroxime, 61.5% to ciprofloxacin/levofloxacin, 92.3% to trimethoprim-sulfamethoxazole, 30.8% to tetracycline, and 7.7% to azithromycin. Eight ampicillin-resistant isolates were β-lactamase positive; of these, 6 carried blaTEM-1 and 2 carried blaROB-1, whereas 4 were β-lactamase negative. Genetic variations in mrdA, mepA, and pbpG were correlated with amoxicillin-clavulanate non-susceptibility, whereas variations in ftsI and lpoA conferred cefuroxime resistance. Five variations in gyrA, 2 in gyrB, 3 in parC, 1 in parE, and 1 in the parC-parE intergenic region were associated with levofloxacin/ciprofloxacin non-susceptibility. Among these genes, 8 variations were linked to high-level levofloxacin resistance. Six variations in folA were associated with trimethoprim-sulfamethoxazole resistance. Plasmid-bearing tet(B) and mef(A) genes were responsible for tetracycline and azithromycin resistance in 4 and 1 MDR isolates, respectively.ConclusionsThis study clarified the molecular epidemiology of MDR in NTHi. This can benefit the monitoring of drug resistance trends in NTHi and the adequate medical management of patients with NTHi infection.

Antibiotic susceptibility of staphylococcus aureus strains isolated from various clinical specimens in a tertiary hospital

Aims: Staphylococcus aureus infection rates, which are the cause of infections, have rapidly risen in both hospitals and society, constituting a concern. In this study, it was aimed to examine the antibiotic susceptibility of S. aureus strains isolated from patients treated in a tertiary state hospital for four years. Methods: A retrospective analysis was performed on S. aureus strains (n=584) identified from clinical samples delivered to the medical microbiology laboratory of Niğde Ömer Halisdemir University Training and Research Hospital for bacterial culture between 2016 and 2019. The isolates were identified by standard laboratory procedure. VITEK 2 automated system (bioMerieux, France) was used to identification and antibiotic susceptibilities of evaluate the strains. Results: Strains were most commonly isolated from wound swab (n=173) and blood culture (n=107). While the highest resistance rate was observed against Erythromycin (n=232), the least amikacin (n=16) resistant strain was determined. Vancomycin and teicoplanin resistance was not observed. Conclusion: Multi-drug resistance and MRSA resistance still exist today. The absence of vancomycin and teicoplanin resistance, in addition to the low level of trimethoprim-sulfamethoxazole resistance, is encouraging. This information about S. aureus's susceptibility may be helpful in determining how to administer antibiotics.

Identification and Resistance Testing of Bacteria Causing Nosocomial Infections in Surgery Inpatient Rooms

Background: Nosocomial infections are the most common infections that occur when patients are under medical care in hospitals. The most common pathogenic bacteria that cause nosocomial infections are Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Enterobacter spp, and Klebsiella pneumonia. One of the factors causing a nosocomial infection is the environment. The spread of nosocomial infections in dr. Doris Sylvanus can occur in the surgical ward environment. Therefore, it is necessary to study and know the identification of bacteria and knowing the pattern of antibiotic resistance of bacteria that cause nosocomial infections in the surgical inpatient ward of dr. Doris Sylvanus Hospital. Methods: This type of research used an observational method with a descriptive approach. The research at dr Doris Sylvanus Hospital. The population is dahlia room which consisted of floors, sheets, patient beds, tables, and door handles. Results: Bacterial identification was Staphylococcus aureus at 13.4% and Staphylococcus non-coagulase at 10%, also found Gram-negative bacteria suspected Salmonella sp. 3.3% and other bacteria at 73.3% The results of the Trimethoprim-sulfamethoxazole antibiotic resistance test on S. aureus bacteria had a sensitivity of 50% and Oxacillin had a sensitivity of 75%, while the Trimethoprim-sulfamethoxazole resistance test results on S. non-coagulase bacteria had a sensitivity of 66.7% and Oxacillin had a sensitivity of 100%. Conclusion: The Trimethoprim-sulfamethoxazole antibiotic resistance test on S. aureus bacteria has moderate sensitivity and the Oxacillin antibiotic has a fairly high sensitivity while on S. non-coagulase bacteria have a fairly high sensitivity and oxacillin antibiotics have high sensitivity.

Primary prophylaxis for spontaneous bacterial peritonitis is linked to antibiotic resistance in the Veterans Health Administration.

Analyze peritoneal fluid resistance patterns in patients with a first SBP episode with/without SBPPr using the Veterans Health Administration corporate data warehouse and to evaluate national antibiograms. Corporate data warehouse data were extracted using validated International Classification of Disease-9/10 codes, culture, resistance data, and outcomes of 7553 patients who developed their first inpatient SBP between 2009 and 2019 and compared between those with/without SBPPr. Escherichia coli ( E. coli ) and Klebsiella pneumoniae ( K. pneumoniae ) sensitivity to ciprofloxacin and TMP-SMX was calculated using 2021 Veterans Health Administration antibiogram data from all states. The most common isolates were E. coli , K. pneumoniae , and Staphylococcus species. Veterans taking ciprofloxacin SBBPr had higher fluoroquinolone resistance (34% vs 14% no SBPPr, p <0.0001); those taking TMP-SMX had higher TMP-SMX resistance (40% vs 14%, p <0.0001). SBPPr patients showed higher culture positivity, greater length of stay, higher second SBP, and higher probability of liver transplant rates versus no SBPPr. Multivariable models showed SBBPr to be the only variable associated with gram-negative resistance, and SBPPr was associated with a trend toward longer length of stay. E. coli ciprofloxacin sensitivity rates were 50%-87% and 43%-92% for TMP-SMX. K. pneumoniae ciprofloxacin sensitivity was 76%-100% and 72%-100% for TMP-SMX. Among patients who developed their first SBP episode, there was a higher prevalence of antibiotic resistance in those on SBPPr, with a high rate of fluoroquinolone resistance across the Veterans Health Administration sites.

Household-level risk factors for water contamination and antimicrobial resistance in drinking water among households with children under 5 in rural San Marcos, Cajamarca, Peru

Household water contamination at point of use depends on human, animal and environmental factors embodying all aspects of a One Health approach. This study investigated the association between household factors, the presence of thermotolerant coliform, and the presence of antibiotic resistant bacteria in drinking water among 314 households with children under 5 in Cajamarca, Peru. This study analysed data from a baseline sampling of a randomized controlled trial, including household surveys covering household water management and factors such as household animals, as well as microbiological data from samples collected from drinking water. Data were analysed using generalized linear models. Drinking water samples collected from narrow-mouthed containers were less likely to be contaminated than samples collected from the faucet (OR = 0.55, p = 0.030) or wide mouthed containers. The presence of thermotolerant coliform was associated with owning farm birds, which increased the proportion of contamination from 42.2% to 59.1% (OR = 1.98, p = 0.017) and with animal waste observed in the kitchen area, which increased the prevalence of contamination from 51.4% to 65.6% (OR = 1.80, p = 0.024). Resistance to any antibiotic was higher among pig owners at 60%, relative to non-pig owners at 36.4% (OR = 1.97, p = 0.012) as well as households with free-roaming animals in the kitchen area at 59.6% compared to households without free-roaming animals at 39.7% (OR = 2.24, p = 0.035). Recent child antibiotic use increased the prevalence of trimethoprim-sulfamethoxazole resistance among E. coli isolates to 22.3% relative to 16.7% (OR = 3.00, p = 0.037). Overall, these findings suggest that water storage in a secure container to protect from in-home contamination is likely to be important in providing safe drinking water at point of use. In addition, transmission of thermotolerant coliform and AMR between domestic animals and human drinking water supplies is likely. Further research should explore transmission pathways and methods to support safe drinking water access in multi-species households.

Prevalence, antimicrobial susceptibility, and antibiotic resistance gene transfer of Bacillus strains isolated from pasteurized milk.

Pasteurization is carried out in dairy industries to kill harmful bacteria present in raw milk. However, endospore-forming bacteria, such as Bacillus, cannot be completely eliminated by pasteurization. In this study, a total of 114 Bacillus strains were isolated from 133 pasteurized milk samples. Antibiotic susceptibility tests showed that the percentage of Bacillus with intrinsic resistance to ampicillin and penicillin were 80 and 86%, respectively. Meanwhile, some Bacillus isolates had acquired resistance, including trimethoprim-sulfamethoxazole resistance (10 isolates), clindamycin resistance (8 isolates), erythromycin resistance (2 isolates), and tetracycline resistance (1 isolate). To further locate these acquired resistance genes, the plasmids were investigated in these 16 Bacillus strains. The plasmid profile indicated that Bacillus cereus BA008, BA117, and BA119 harbored plasmids, respectively. Subsequently, the Illumina Novaseq PE150 was applied for the genomic and plasmid DNA sequencing. Notably, the gene tetL encoding tetracycline efflux protein was found to be located on plasmid pBC46-TL of B. cereus BA117. In vitro conjugative transfer indicated that pBC46-TL can be transferred into Bacillus invictae BA142, Bacillus safensis BA143, and Bacillus licheniformis BA130. The frequencies were of 1.5 × 10-7 to 1.7 × 10-5 transconjugants per donor cells. Therefore, Bacillus strains with acquired antibiotic resistance may represent a potential risk for the spread of antibiotic resistance between Bacillus and other clinical pathogens via horizontal gene transfer.

Evaluation of Antibiotic Resistance and adeABC, adeR, adeS Efflux Pump Genes among Foodborne and Clinical Acinetobacter spp. in Türkiye.

The adeABC efflux pump has a crucial role in the resistance of Acinetobacter baumannii strains to antimicrobial agents; it is encoded by adeABC, adeR, adeS genes. We evaluated antibiotic resistance, efflux pump genes, clonal relationships, and analyzed a probable correlation that can exist between antibiotic resistance and the aforementioned genes. We conducted this study on 27 food-originated and 50 human clinical Acinetobacter spp. in Southern Türkiye. MALDI-TOF system and disc diffusion/agar dilution (colistin) methods were used for the identification and antibiotic susceptibility. The efflux pump genes and genetic relatedness of the two groups were investigated by (PCR) and (PFGE) methods. Foodborne A. dijkshoorniae strain was multidrug- resistant (MDR), and none of them resistant to colistin. Most of the clinical isolates (92%) were Extensive-Drug Resistant (XDR); highest resistant to ceftazidime, piperacillin-tazobactam, and imipenem (47, 94%), and were lowest to colistin (7, 14%), respectively. adeABC, and adeR, adeS genes were (23, 85.2%), (9, 33.3%), (27, 100%) and (10, 37.3%), (18, 66.7%) in foodborne strains respectively. These rates were (43, 86%), (48, 96%), (50, 100%), and (34, 68%), (48, 96.7%) in clinical strains respectively. A positive correlation existed between adeA gene positivity and piperacillintazobactam, ceftazidime, gentamycin, imipenem (P=0.048), amikacin (P=0.007) and trimethoprimsulfamethoxazole (P=0.029) resistance in clinical strains. A positive correlation of trimethoprimsulfamethoxazole resistance and adeS gene positivity was seen in foodborne strains (P=0.018). Multiple-efflux pump genes rise in parallel to multidrug-resistance in clinical isolates, while susceptible to diverse antibiotics; food may be a potential provenance for the dissemination of adeABC, adeR and adeS genes.

Antimicrobial resistance trends among canine Escherichia coli isolated at a New York veterinary diagnostic laboratory between 2007 and 2020

Dogs are a potential source of drug-resistant Escherichia coli, but very few large-scale antimicrobial resistance surveillance studies have been conducted in the canine population. Here, we assess the antimicrobial susceptibility patterns, identify temporal resistance and minimum inhibitory concentration (MIC) trends, and describe associations between resistance phenotypes among canine clinical E. coli isolates in the northeastern United States. Through a retrospective study design, we collected MICs from 7709 E. coli isolates from canine infections at the Cornell University Animal Health Diagnostic Center between 2007 and 2020. The available clinical data were limited to body site. Isolates were classified as resistant or susceptible to six (urinary) and 22 (non-urinary) antimicrobials based on Clinical and Laboratory Standards Institute breakpoints. We used the Mann-Kendall test (MKT) and Sen's slope to identify the presence of a significant trend in the percent of resistant isolates over the study period. Multivariable logistic regression (MLR) models were built with ceftiofur, enrofloxacin, or trimethoprim-sulfamethoxazole resistance as the outcome and either body site and isolation date, or resistance to other antimicrobials as predictors. MIC trends were characterized with survival analysis models, controlling for body site and year of isolation. Overall, 16.4% of isolates were resistant to enrofloxacin, 14.3% to ceftiofur, and 14% to trimethoprim-sulfamethoxazole. The MKT and Sen's slope revealed a significant decreasing temporal trend for gentamicin and trimethoprim-sulfamethoxazole resistance among non-urinary isolates. No significant temporal resistance trends were detected by MKT for other antimicrobials. However, controlling for body-site in MLR models identified a decrease in resistance rates to enrofloxacin and trimethoprim-sulfamethoxazole after 2010. Similarly, survival analysis data confirmed these findings and showed a decrease in MIC values after 2010 for gentamicin and trimethoprim-sulfamethoxazole, but an increase in cephalosporin MICs. MLR showed that non-urinary isolates were significantly more likely than urinary isolates to demonstrate in vitro resistance to ceftiofur, enrofloxacin, and trimethoprim-sulfamethoxazole after controlling for year of isolation. We identified a higher level of ceftiofur resistance among enrofloxacin resistant isolates from urinary and non-urinary origins. Our findings confirmed that dogs are still a non-negligeable reservoir of drug-resistant E. coli in the northeastern United States. The increase in extended-spectrum cephalosporin MIC values in 2018–2020 compared to 2007–2010 constitutes a particularly worrying issue; the relationship between ceftiofur and enrofloxacin resistance suggests that the use of fluoroquinolones could contribute to this trend. Trimethoprim-sulfamethoxazole may be a good first-line choice for empiric treatment of E. coli infections; it is already recommended for canine urinary tract infections.

Can Urinalysis and Past Medical History of Kidney Stones Predict Urine Antibiotic Resistance?

IntroductionUrinary tract infections (UTI) are one of the most common infections encountered in the emergency department (ED) with an estimated 2–3 million annual visits. Commonly prescribed antibiotics for UTIs have shown growing rates of resistance. Previous studies lack direction on improving UTI treatment based on the labs available to the bedside clinician.MethodsWe sought to determine if antibiotic resistance in UTIs was related to demographics, urinalysis, and history of renal failure or kidney stones. We conducted an analysis of 892 women ≥18 years of age discharged from the ED with a UTI diagnosis. We assessed predictors of nitrofurantoin resistance, cefazolin resistance, ciprofloxacin resistance, and trimethoprim-sulfamethoxazole resistance using unadjusted and multivariable logistic regression models.ResultsAntibiotic resistance was 13.6% for nitrofurantoin, 11.9% for cefazolin, 12.8% for ciprofloxacin, and 17.1% for trimethoprim-sulfamethoxazole. In multivariable analysis, significant independent associations with an increased likelihood of resistance to nitrofurantoin were observed for less urine blood (OR [per 1 category increase of score] 0.81; P = 0.02); greater mucous (OR [per 1 category increase of score] 1.22; P = 0.02); less specific gravity urine (OR [per 1 category increase] 0.87; P = 0.04), and presence of any history of kidney stones (OR 3.24; P = 0.01). There were no significant predictors for cefazolin resistance (all P ≥0.06); age was the only significant predictor of ciprofloxacin resistance (OR per 10 year increase] 1.10, P = 0.05), and lower specific gravity urine was significantly associated with an increased risk of resistance to trimethoprim- sulfamethoxazole (OR [per 1 category increase] 0.88, P = 0.04).ConclusionWomen with any history of kidney stones may have bacteriuria resistant to nitrofurantoin, suggesting that providers might consider alternative antibiotic therapies in this scenario.

Comparison of genome-derived and phenotypic antimicrobial resistance profiles of Shigella species isolated from patients with symptoms of gastrointestinal disease in England, 2015-2020

Increasing antimicrobial resistance (AMR) in Shigellaspecies is a global public health problem. We compared genotypic and phenotypic methods for the detection of AMR in Shigellaspecies to evaluate the use of genome data for surveillance and monitoring of emerging AMR. Whole genome sequencing (WGS) data from 388 isolates of all four Shigella species were analysed for the presence/absence of specific AMR determinants and selected accordingly. Phenotypic antimicrobial susceptibility testing was performed using in-agar dilution on all viable and pure isolates (n=358). The genotypic and phenotypic AMR profiles were then compared. There were 335 (93.6%) isolates resistant to at least one antimicrobial and 222 (62%) isolates were multi-drug resistant, of which the majority (77%) were associated with foreign travel. Out of a possible 2864 isolate/antimicrobial class combinations, we identified 119 unexpected results, giving an overall concordance of 96.8% between the two methods. There were 54 samples that had an AMR determinant expected to confer resistance that were phenotypically susceptible, of which 31/54 (57.4%) were associated with tetracycline resistance and trimethoprim-sulfamethoxazole resistance. There were 65 that were phenotypically resistant to a specific antimicrobial class, but no AMR determinant was detected, of which 32/65 (49.2%) were associated with isolates harbouring a single gyrA mutation and exhibiting an unexpectedly high minimum inhibitory concentration (MIC) to ciprofloxacin. Although comparisons between both methods showed good correlation between the genotypic and phenotypic AMR profiles, phenotypic monitoring is required to identify novel AMR mechanisms and to update reference database used for WGS analysis.

Outpatient antibiogram and predictors of ciprofloxacin and trimethoprim-sulfamethoxazole resistant urinary tract infections.

Context: Rising antibiotic resistance has transcended hospital boundaries and impacted individuals with community acquired urinary tract infections (UTI). Scant data on antibiotic resistance in outpatient settings exists and most studies in the United States (U.S.) have identified predictors of resistance in acute-care settings. Objective: Determine the antibiogram among Escherichia coli isolates and factors associated with ciprofloxacin and trimethoprim-sulfamethoxazole (TMP-SMX) resistant gram-negative urinary isolates. Study Design: Retrospective cohort study. Setting: Two primary care, safety-net clinics in Houston, TX between 11/2018 and 3/2020. Population studied: Patients aged 18 and older presenting with provider suspected uncomplicated or complicated UTI. Outcome measures: Resistance and predictors of resistance to UTI-relevant antibiotics. Results: Among 1265 cultures collected, 372 (28.4%) were positive. We detected E. coli (50.3%) and Group B Streptococcus (18.6%) most frequently. Our patient population consisted mostly of Hispanic (75.7%) females (92.5%) born outside the U.S. (67.3%) with a mean age of 47. Among patients with E. coli isolated (n=189), antibiotic resistance was highest to ampicillin (63%), TMP-SMX (44%), ciprofloxacin (31%), and cefazolin (30%); no or low resistance against amikacin (0%), fosfomycin (0%), and nitrofurantoin (2.7%) was detected. Approximately 12% of E. coli isolates were extended-spectrum beta-lactamase positive. Having a prior UTI caused by a TMP-SMX resistant gram-negative organism and being born outside the U.S increased the odds of TMP-SMX resistance by 3.71 (95% confidence interval: 1.6-9.2) and 3.08 (95% CI: 1.6-6.3), respectively. Having a complicated UTI (odds ratio (OR): 3.58; 95% CI: 1.1-12.1), prior fluoroquinolone use (OR: 6.81; 95% CI: 1.7-34.1) and a prior UTI with ciprofloxacin resistance (OR: 7.84; 95% CI: 3.2-20.7) increased the odds of having a ciprofloxacin resistance. Conclusion: The Infectious Disease Society of America cautions against prescribing an antibiotic if regional resistance exceeds 20%. We constructed an antibiogram and found resistance surpassed this threshold for TMP-SMX and ciprofloxacin and identified factors associated with resistance to these agents. Assessing these characteristics during clinical decision making may improve antibiotic-organism susceptibility concordance in primary care.