# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 5067 | 0 | 0.9885 | Stepwise Evolution of a Klebsiella pneumoniae Clone within a Host Leading to Increased Multidrug Resistance. Five bla(CTX-M-14)-positive Klebsiella pneumoniae isolates (KpWEA1, KpWEA2, KpWEA3, KpWEA4-1, and KpWEA4-2) were consecutively obtained from a patient with relapsed acute myeloid leukemia who was continuously administered antimicrobials. Compared with KpWEA1 and KpWEA2, KpWEA3 showed decreased susceptibility to antimicrobials, and KpWEA4-1 and KpWEA4-2 (isolated from a single specimen) showed further-elevated multidrug-resistance (MDR) phenotypes. This study aims to clarify the clonality of the five isolates and their evolutionary processes leading to MDR by comparison of these complete genomes. The genome comparison revealed KpWEA1 was the antecedent of the other four isolates, and KpWEA4-1 and KpWEA4-2 independently emerged from KpWEA3. Increasing levels of MDR were acquired by gradual accumulation of genetic alterations related to outer membrane protein expression: the loss of OmpK35 and upregulation of AcrAB-TolC occurred in KpWEA3 due to ramA overexpression caused by a mutation in ramR; then OmpK36 was lost in KpWEA4-1 and KpWEA4-2 by different mechanisms. KpWEA4-2 further acquired colistin resistance by the deletion of mgrB. In addition, we found that exuR and kdgR, which encode repressors of hexuronate metabolism-related genes, were disrupted in different ways in KpWEA4-1 and KpWEA4-2. The two isolates also possessed different amino acid substitutions in AtpG, which occurred at very close positions. These genetic alterations related to metabolisms may compensate for the deleterious effects of major porin loss. Thus, our present study reveals the evolutionary process of a K. pneumoniae clone leading to MDR and also suggests specific survival strategies in the bacteria that acquired MDR by the genome evolution. IMPORTANCE Within-host evolution is a survival strategy that can occur in many pathogens and is often associated with the emergence of novel antimicrobial-resistant (AMR) bacteria. To analyze this process, suitable sets of clinical isolates are required. Here, we analyzed five Klebsiella pneumoniae isolates which were consecutively isolated from a patient and showed a gradual increase in the AMR level. By genome sequencing and other analyses, we show that the first isolate was the antecedent of the later isolates and that they gained increased levels of antimicrobial resistance leading to multidrug resistance (MDR) by stepwise changes in the expression of outer membrane proteins. The isolates showing higher levels of MDR lost major porins but still colonized the patient's gut, suggesting that the deleterious effects of porin loss were compensated for by the mutations in hexuronate metabolism-related genes and atpG, which were commonly detected in the MDR isolates. | 2021 | 34817239 |
| 2505 | 1 | 0.9885 | Resistance in nonfermenting gram-negative bacteria: multidrug resistance to the maximum. Nonfermenting gram-negative bacteria pose a particular difficulty for the healthcare community because they represent the problem of multidrug resistance to the maximum. Important members of the group in the United States include Pseudomonas aeruginosa, Acinetobacter baumannii, Stenotrophomonas maltophilia, and Burkholderia cepacia. These organisms are niche pathogens that primarily cause opportunistic healthcare-associated infections in patients who are critically ill or immunocompromised. Multidrug resistance is common and increasing among gram-negative nonfermenters, and a number of strains have now been identified that exhibit resistance to essentially all commonly used antibiotics, including antipseudomonal penicillins and cephalosporins, aminoglycosides, tetracyclines, fluoroquinolones, trimethoprim-sulfamethoxazole, and carbapenems. Polymyxins are the remaining antibiotic drug class with fairly consistent activity against multidrug-resistant strains of P aeruginosa, Acinetobacter spp, and S maltophilia. However, most multidrug-resistant B cepacia are not susceptible to polymyxins, and systemic polymyxins carry the risk of nephrotoxicity for all patients treated with these agents, the elderly in particular. A variety of resistance mechanisms have been identified in P aeruginosa and other gram-negative nonfermenters, including enzyme production, overexpression of efflux pumps, porin deficiencies, and target-site alterations. Multiple resistance genes frequently coexist in the same organism. Multidrug resistance in gram-negative nonfermenters makes treatment of infections caused by these pathogens both difficult and expensive. Improved methods for susceptibility testing are needed when dealing with these organisms, including emerging strains expressing metallo-beta-lactamases. Improved antibiotic stewardship and infection-control measures will be needed to prevent or slow the emergence and spread of multidrug-resistant, nonfermenting gram-negative bacilli in the healthcare setting. | 2006 | 16813979 |
| 2504 | 2 | 0.9885 | Resistance in nonfermenting gram-negative bacteria: multidrug resistance to the maximum. Nonfermenting gram-negative bacteria pose a particular difficulty for the healthcare community because they represent the problem of multidrug resistance to the maximum. Important members of the group in the United States include Pseudomonas aeruginosa, Acinetobacter baumannii, Stenotrophomonas maltophilia, and Burkholderia cepacia. These organisms are niche pathogens that primarily cause opportunistic healthcare-associated infections in patients who are critically ill or immunocompromised. Multidrug resistance is common and increasing among gram-negative nonfermenters, and a number of strains have now been identified that exhibit resistance to essentially all commonly used antibiotics, including antipseudomonal penicillins and cephalosporins, aminoglycosides, tetracyclines, fluoroquinolones, trimethoprim-sulfamethoxazole, and carbapenems. Polymyxins are the remaining antibiotic drug class with fairly consistent activity against multidrug-resistant strains of P aeruginosa, Acinetobacter spp, and S maltophilia. However, most multidrug-resistant B cepacia are not susceptible to polymyxins, and systemic polymyxins carry the risk of nephrotoxicity for all patients treated with these agents, the elderly in particular. A variety of resistance mechanisms have been identified in P aeruginosa and other gram-negative nonfermenters, including enzyme production, overexpression of efflux pumps, porin deficiencies, and target-site alterations. Multiple resistance genes frequently coexist in the same organism. Multidrug resistance in gram-negative nonfermenters makes treatment of infections caused by these pathogens both difficult and expensive. Improved methods for susceptibility testing are needed when dealing with these organisms, including emerging strains expressing metallo-beta-lactamases. Improved antibiotic stewardship and infection-control measures will be needed to prevent or slow the emergence and spread of multidrug-resistant, nonfermenting gram-negative bacilli in the healthcare setting. | 2006 | 16735148 |
| 5380 | 3 | 0.9879 | In Vitro Screening of a 1280 FDA-Approved Drugs Library against Multidrug-Resistant and Extensively Drug-Resistant Bacteria. Alternative strategies against multidrug-resistant (MDR) bacterial infections are suggested to clinicians, such as drug repurposing, which uses rapidly available and marketed drugs. We gathered a collection of MDR bacteria from our hospital and performed a phenotypic high-throughput screening with a 1280 FDA-approved drug library. We used two Gram positive (Enterococcus faecium P5014 and Staphylococcus aureus P1943) and six Gram negative (Acinetobacter baumannii P1887, Klebsiella pneumoniae P9495, Pseudomonas aeruginosa P6540, Burkholderia multivorans P6539, Pandoraea nosoerga P8103, and Escherichia coli DSM105182 as the reference and control strain). The selected MDR strain panel carried resistance genes or displayed phenotypic resistance to last-line therapies such as carbapenems, vancomycin, or colistin. A total of 107 compounds from nine therapeutic classes inhibited >90% of the growth of the selected Gram negative and Gram positive bacteria at a drug concentration set at 10 µmol/L, and 7.5% were anticancer drugs. The common hit was the antiseptic chlorhexidine. The activity of niclosamide, carmofur, and auranofin was found against the selected methicillin-resistant S. aureus. Zidovudine was effective against colistin-resistant E. coli and carbapenem-resistant K. pneumoniae. Trifluridine, an antiviral, was effective against E. faecium. Deferoxamine mesylate inhibited the growth of XDR P. nosoerga. Drug repurposing by an in vitro screening of a drug library is a promising approach to identify effective drugs for specific bacteria. | 2022 | 35326755 |
| 4781 | 4 | 0.9879 | Isolation and Characterization of New Bacteriophages against Staphylococcal Clinical Isolates from Diabetic Foot Ulcers. Staphylococcus sp. is the most common bacterial genus in infections related to diabetic foot ulcers (DFUs). The emergence of multidrug-resistant bacteria places a serious burden on public health systems. Phage therapy is an alternative treatment to antibiotics, overcoming the issue of antibiotic resistance. In this study, six phages (SAVM01 to SAVM06) were isolated from effluents and were used against a panel of staphylococcal clinical samples isolated from DFUs. A genomic analysis revealed that the phages belonged to the Herelleviridae family, with sequences similar to those of the Kayvirus genus. No lysogeny-associated genes, known virulence or drug resistance genes were identified in the phage genomes. The phages displayed a strong lytic and antibiofilm activity against DFU clinical isolates, as well as against opportunistic pathogenic coagulase-negative staphylococci. The results presented here suggest that these phages could be effective biocontrol agents against staphylococcal clinical isolates from DFUs. | 2023 | 38140529 |
| 6372 | 5 | 0.9878 | Sensitizing multi drug resistant Staphylococcus aureus isolated from surgical site infections to antimicrobials by efflux pump inhibitors. BACKGROUND: Staphylococcus aureus is a common hospital acquired infections pathogen. Multidrug-resistant Methicillin-resistant Staphylococcus aureus represents a major problem in Egyptian hospitals. The over-expression of efflux pumps is a main cause of multidrug resistance. The discovery of efflux pump inhibitors may help fight multidrug resistance by sensitizing bacteria to antibiotics. This study aimed to investigate the role of efflux pumps in multidrug resistance. METHODS: Twenty multidrug resistant S. aureus isolates were selected. Efflux pumps were screened by ethidium bromide agar cartwheel method and polymerase chain reaction. The efflux pump inhibition by seven agents was tested by ethidium bromide agar cartwheel method and the effect on sensitivity to selected antimicrobials was investigated by broth microdilution method. RESULTS: Seventy percent of isolates showed strong efflux activity, while 30% showed intermediate activity. The efflux genes mdeA, norB, norC, norA and sepA were found to play the major role in efflux, while genes mepA, smr and qacA/B had a minor role. Verapamil and metformin showed significant efflux inhibition and increased the sensitivity to tested antimicrobials, while vildagliptin, atorvastatin, domperidone, mebeverine and nifuroxazide showed no effect. CONCLUSION: Efflux pumps are involved in multidrug resistance in Staphylococcus aureus. Efflux pump inhibitors could increase the sensitivity to antimicrobials. | 2020 | 34394224 |
| 5181 | 6 | 0.9878 | Differential Expression of fimH, ihf, upaB, and upaH Genes in Biofilms- and Suspension-Grown Bacteria From Samples of Different Uropathogenic Strains of Escherichia coli. Uropathogenic Escherichia coli (UPEC) strains are the main bacteria that cause urinary tract infections (UTIs). UPEC are a significant public health hazard due to their high proliferation, antibiotic resistance, and infection recurrence. The ability to form biofilms is a mechanism of antibiotic resistance, which requires the expression of different genes such as fimH, ihf, upaB, and upaH. Despite the relevance of biofilm formation in bacterial pathogenicity, differences in the expression level of these genes among bacterial growth conditions have been little studied. Here, we have characterized the expression of fimH, ihf, upaB, and upaH genes in biofilms and suspension-grown bacteria of different E. coli strains. These included the UPEC CFT073, the multidrug-resistant strain CDC-AR-0346, and clinical isolates obtained from UTI patients. The expression of fimH, ihf, upaB, and upaH was markedly heterogeneous in clinical isolates, both in terms of transcript levels and response to suspension or biofilm conditions. That expression pattern was distinct from the one in UPEC CFT073, where upaB and upaH were upregulated and ihf and fimH were slightly downregulated in biofilm. In conclusion, the data presented here show that the pattern of biofilm-associated genes in the clinical isolates from UTI patients is not fully related to the reference strain of UPEC CFT073. However, analysis of a larger number of samples is required. | 2024 | 39703715 |
| 3746 | 7 | 0.9878 | Severe Disseminated Infection with Emerging Lineage of Methicillin-Sensitive Staphylococcus aureus. We report a case of severe disseminated infection in an immunocompetent man caused by an emerging lineage of methicillin-sensitive Staphylococcus aureus clonal complex 398. Genes encoding classic virulence factors were absent. The patient made a slow recovery after multiple surgical interventions and a protracted course of intravenous flucloxacillin. | 2019 | 30561304 |
| 2197 | 8 | 0.9877 | Antimicrobial susceptibility patterns of bacteria that commonly cause bacteremia at a tertiary hospital in Zambia. Background: Bloodstream infections and antimicrobial resistance cause global increases in morbidity and mortality. Aim: We evaluated the antimicrobial susceptibility patterns of bacteria that commonly cause bacteremia in humans. Materials & methods: We conducted a retrospective cross-sectional study at the University Teaching Hospitals in Lusaka, Zambia, using Laboratory Information Systems. Results: The commonest isolated bacteria associated with sepsis were Klebsiella pneumoniae. The distribution of bacteria associated with bacteremia in different wards and departments pneumonia. The distribution of bacteria associated with bacteremia in different wards and departments at University Teaching Hospitals was were statistically significant (χ2 = 1211.518; p < 0.001). Conclusion:K. pneumoniae, Escherichia coli, Pantoea agglomerans and Enterococcus species have developed high resistance levels against ampicillin, cefotaxime, ciprofloxacin, gentamicin and trimethoprim/sulfamethoxazole and a very low resistance levels against imipenem and Amikacin. | 2020 | 33315486 |
| 5169 | 9 | 0.9877 | Genetic Adaptation and Acquisition of Macrolide Resistance in Haemophilus spp. during Persistent Respiratory Tract Colonization in Chronic Obstructive Pulmonary Disease (COPD) Patients Receiving Long-Term Azithromycin Treatment. Patients with chronic obstructive pulmonary disease (COPD) benefit from the immunomodulatory effect of azithromycin, but long-term administration may alter colonizing bacteria. Our goal was to identify changes in Haemophilus influenzae and Haemophilus parainfluenzae during azithromycin treatment. Fifteen patients were followed while receiving prolonged azithromycin treatment (Hospital Universitari de Bellvitge, Spain). Four patients (P02, P08, P11, and P13) were persistently colonized by H. influenzae for at least 3 months and two (P04 and P11) by H. parainfluenzae. Isolates from these patients (53 H. influenzae and 18 H. parainfluenzae) were included to identify, by whole-genome sequencing, antimicrobial resistance changes and genetic variation accumulated during persistent colonization. All persistent lineages isolated before treatment were azithromycin-susceptible but developed resistance within the first months, apart from those belonging to P02, who discontinued the treatment. H. influenzae isolates from P08-ST107 acquired mutations in 23S rRNA, and those from P11-ST2480 and P13-ST165 had changes in L4 and L22. In H. parainfluenzae, P04 persistent isolates acquired changes in rlmC, and P11 carried genes encoding MefE/MsrD efflux pumps in an integrative conjugative element, which was also identified in H. influenzae P11-ST147. Other genetic variation occurred in genes associated with cell wall and inorganic ion metabolism. Persistent H. influenzae strains all showed changes in licA and hgpB genes. Other genes (lex1, lic3A, hgpC, and fadL) had variation in multiple lineages. Furthermore, persistent strains showed loss, acquisition, or genetic changes in prophage-associated regions. Long-term azithromycin therapy results in macrolide resistance, as well as genetic changes that likely favor bacterial adaptation during persistent respiratory colonization. IMPORTANCE The immunomodulatory properties of azithromycin reduce the frequency of exacerbations and improve the quality of life of COPD patients. However, long-term administration may alter the respiratory microbiota, such as Haemophilus influenzae, an opportunistic respiratory colonizing bacteria that play an important role in exacerbations. This study contributes to a better understanding of COPD progression by characterizing the clinical evolution of H. influenzae in a cohort of patients with prolonged azithromycin treatment. The emergence of macrolide resistance during the first months, combined with the role of Haemophilus parainfluenzae as a reservoir and source of resistance dissemination, is a cause for concern that may lead to therapeutic failure. Furthermore, genetic variations in cell wall and inorganic ion metabolism coding genes likely favor bacterial adaptation to host selective pressures. Therefore, the bacterial pathoadaptive evolution in these severe COPD patients raise our awareness of the possible spread of macrolide resistance and selection of host-adapted clones. | 2023 | 36475849 |
| 2166 | 10 | 0.9876 | Distribution and drug resistance of pathogenic bacteria in emergency patients. BACKGROUND: Antibiotic resistance has become a global threat for human health, calling for rational use of antibiotics. AIM: To analyze the distribution and drug resistance of the bacteria, providing the prerequisite for use of antibiotics in emergency patients. METHODS: A total of 2048 emergency patients from 2013 to 2017 were enrolled. Their clinical examination specimens were collected, followed by isolation of bacteria. The bacterial identification and drug susceptibility testing were carried out. RESULTS: A total of 3387 pathogens were isolated. The top six pathogens were Acinetobacter baumannii (660 strains), Staphylococcus aureus (436 strains), Klebsiella pneumoniae (347 strains), Pseudomonas aeruginosa (338 strains), Escherichia coli (237 strains), and Candida albicans (207 strains). The isolation rates of these pathogens decreased year by year except Klebsiella pneumoniae, which increased from 7.1% to 12.1%. Acinetobacter baumannii is a widely-resistant strain, with multiple resistances to imipenem, ciprofloxacin, minocycline and tigecycline. The Staphylococcus aureus had high resistance rates to levofloxacin, penicillin G, and tetracycline. But the susceptibility of it to vancomycin and tigecycline were 100%. Klebsiella pneumoniae had high resistance rates to imipenem, cefoperazone/sulbactam, amikacin, and ciprofloxacin, with the lowest resistance rate to tigecycline. The resistance rates of Pseudomonas aeruginosa to cefoperazone/sulbactam and imipenem were higher, with the resistance rate to amikacin below 10%. Besides, Escherichia coli had high resistance rates to ciprofloxacin and cefoperazone/sulbactam and low resistance rates to imipenem, amikacin, and tigecycline. CONCLUSION: The pathogenic bacteria isolated from the emergency patients were mainly Acinetobacter baumannii, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans. The detection rates of drug-resistant bacteria were high, with different bacteria having multiple drug resistances to commonly used antimicrobial agents, guiding the rational use of drugs and reducing the production of multidrug-resistant bacteria. | 2019 | 31667167 |
| 2108 | 11 | 0.9875 | Prevalence and Molecular Characterization of Carbapenemase-Producing Multidrug-Resistant Bacteria in Diabetic Foot Ulcer Infections. Background: Diabetic foot ulcers (DFUs) represent severe complications in diabetic patients, often leading to chronic infections and potentially resulting in nontraumatic lower-limb amputations. The increasing incidence of multidrug-resistant (MDR) bacteria in DFUs complicates treatment strategies and worsens patient prognosis. Among these pathogens, carbapenemase-producing pathogens have emerged as particularly concerning owing to their resistance to β-lactam antibiotics, including carbapenems. Methods: This study evaluated the prevalence of MDR bacteria, specifically carbapenemase-producing pathogens, in DFU infections. A total of 200 clinical isolates from DFU patients were analyzed via phenotypic assays, including the modified Hodge test (MHT) and the Carba NP test, alongside molecular techniques to detect carbapenemase-encoding genes (blaKPC, blaNDM, blaVIM, blaIMP, and blaOXA-48). Results: Among the isolates, 51.7% were confirmed to be carbapenemase producers. The key identified pathogens included Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, and Escherichia coli. The most commonly detected carbapenemase genes were blaKPC (27.6%) and blaNDM (24.1%). Carbapenemase-producing isolates presented high resistance to β-lactam antibiotics, whereas non-carbapenemase-producing isolates presented resistance through mechanisms such as porin loss and efflux pumps. Conclusions: The findings of this study highlight the significant burden of MDR infections, particularly carbapenemase-producing organisms, in DFUs. MDR infections were strongly associated with critical clinical parameters, including pyrexia (p = 0.017), recent antibiotic use (p = 0.003), and the severity of infections. Notably, the need for minor amputations was much higher in MDR cases (p < 0.001), as was the need for major amputations (p < 0.001). MDR infections were also strongly associated with polymicrobial infections (p < 0.001). Furthermore, Wagner ulcer grade ≥II was more common in MDR cases (p = 0.002). These results emphasize the urgent need for enhanced microbiological surveillance and the development of tailored antimicrobial strategies to combat MDR pathogens effectively. Given the high prevalence of carbapenem resistance, there is an immediate need to explore novel therapeutic options to improve clinical outcomes for diabetic patients with DFUs. | 2025 | 39857026 |
| 2258 | 12 | 0.9875 | Antimicrobial-Resistant Bacteria in Infected Wounds, Ghana, 2014(1). Wound infections are an emerging medical problem worldwide, frequently neglected in under-resourced countries. Bacterial culture and antimicrobial drug resistance testing of infected wounds in patients in a rural hospital in Ghana identified no methicillin-resistant Staphylococcus aureus or carbapenem-resistant Enterobacteriaceae but identified high combined resistance of Enterobacteriaceae against third-generation cephalosporins and fluoroquinolones. | 2018 | 29664368 |
| 9760 | 13 | 0.9875 | Mutations leading to ceftolozane/tazobactam and imipenem/cilastatin/relebactam resistance during in vivo exposure to ceftazidime/avibactam in Pseudomonas aeruginosa. Identifying resistance mechanisms to novel antimicrobials informs treatment strategies during infection and antimicrobial development. Studying resistance that develops during the treatment of an infection can provide the most clinically relevant mutations conferring resistance, but cross-sectional studies frequently identify multiple candidate resistance mutations without resolving the driver mutation. We performed whole-genome sequencing of longitudinal Pseudomonas aeruginosa from a patient whose P. aeruginosa developed imipenem/cilastatin/relebactam and ceftolozane/tazobactam resistance during ceftazidime/avibactam treatment. This analysis determined new mutations that arose in isolates resistant to both imipenem/cilastatin/relebactam and ceftolozane/tazobactam. Mutations in penicillin-binding protein 3 ftsI, the MexAB-OprM repressor nalD, and a virulence regulator pvdS were found in resistant isolates. Importantly, drug efflux was not increased in the resistant isolate compared to the most closely related susceptible isolates. We conclude that mutations in peptidoglycan synthesis genes can alter the efficacy of multiple antimicrobials. IMPORTANCE: Antibiotic resistance is a significant challenge for physicians trying to treat infections. The development of novel antibiotics to treat resistant infections has not been prioritized for decades, limiting treatment options for infections caused by many high-priority pathogens. Cross-resistance, when one mutation provides resistance to multiple antibiotics, is most problematic. Mutations that cause cross-resistance need to be considered when developing new antibiotics to guide developers toward drugs with different targets, and thus a better likelihood of efficacy. This work was undertaken to determine the mutation that caused resistance to three antibiotics for highly resistant Pseudomonas aeruginosa infection treatment while the bacteria were exposed to only one of these agents. The findings provide evidence that drug developers should endeavor to find effective antibiotics with new targets and that medical providers should utilize medications with different mechanisms of action in bacteria that have become resistant to even one of these three agents. | 2025 | 39932323 |
| 2318 | 14 | 0.9875 | Distribution of pathogenic bacteria in lower respiratory tract infection in lung cancer patients after chemotherapy and analysis of integron resistance genes in respiratory tract isolates of uninfected patients. BACKGROUND: We studied the distribution of pathogenic bacteria in lower respiratory tract infection in lung cancer patients after chemotherapy and analyzed the integron resistance genes in respiratory tract isolates of uninfected patients. METHODS: Retrospective analysis was used to select sputum samples from 400 lung cancer patients after chemotherapy admitted in Fuyang People's Hospital from July 2017 to July 2019. Culture, isolation and identification of strains were conducted in accordance with the national clinical examination operating procedures. RESULTS: A total of 134 strains were identified. In 120 patients with pulmonary infection, 114 strains were cultured. Twenty strains of klebsiella pneumoniae were cultured in 280 patients without pulmonary infection. Among the 134 strains, the detection rate of gram-negative bacteria was 79.10%. The first four strains were Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Haemophilus influenzae. The gram-positive bacteria detection rate was 4.47%, mainly Staphylococcus aureus and Streptococcus. The fungus detection rate was 16.42%. The drug sensitivity results showed that the resistance rate of gram-negative bacillus to penicillin and cephalosporin was higher, and were more sensitive to carbapenem, piperacillin tazobactam and cefoperazone sulbactam. Gram-positive cocci were resistant to penicillin, macrolide and clindamycin, and sensitive to linezolid, vancomycin and rifampicin. All strains of fungal culture were candida albicans, which were sensitive to common antifungal drugs. Among the 20 strains of klebsiella pneumoniae cultured in sputum specimens of non-infected patients with lung cancer undergoing chemotherapy, 2 strains were integron-positive strains, and all of them were class I integrons. CONCLUSIONS: Lung cancer patients after chemotherapy have a high resistance to commonly used antimicrobial drugs, so it is necessary to detect the resistance of pathogenic microorganisms in clinical practice. The strains carried by patients with lung cancer without pulmonary infection during chemotherapy can isolate type I integrons, suggesting that the spread of drug resistance at gene level should be closely detected. | 2020 | 32944333 |
| 3739 | 15 | 0.9874 | Survey of drug resistance associated gene mutations in Mycobacterium tuberculosis, ESKAPE and other bacterial species. Tuberculosis treatment includes broad-spectrum antibiotics such as rifampicin, streptomycin and fluoroquinolones, which are also used against other pathogenic bacteria. We developed Drug Resistance Associated Genes database (DRAGdb), a manually curated repository of mutational data of drug resistance associated genes (DRAGs) across ESKAPE (i.e. Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) pathogens, and other bacteria with a special focus on Mycobacterium tuberculosis (MTB). Analysis of mutations in drug-resistant genes listed in DRAGdb suggested both homoplasy and pleiotropy to be associated with resistance. Homoplasy was observed in six genes namely gidB, gyrA, gyrB, rpoB, rpsL and rrs. For these genes, drug resistance-associated mutations at codon level were conserved in MTB, ESKAPE and many other bacteria. Pleiotropy was exemplified by a single nucleotide mutation that was associated with resistance to amikacin, gentamycin, rifampicin and vancomycin in Staphylococcus aureus. DRAGdb data also revealed that mutations in some genes such as pncA, inhA, katG and embA,B,C were specific to Mycobacterium species. For inhA and pncA, the mutations in the promoter region along with those in coding regions were associated with resistance to isoniazid and pyrazinamide respectively. In summary, the DRAGdb database is a compilation of all the major MTB drug resistance genes across bacterial species, which allows identification of homoplasy and pleiotropy phenomena of DRAGs. | 2020 | 32488120 |
| 1481 | 16 | 0.9874 | Molecular versus conventional assay for diagnosis of hospital-acquired pneumonia in critically ill patients: a single center experience. PURPOSE: Lower respiratory tract infections are reported as one of top five causes of mortality and morbidity in the world. A bacterial etiology is often involved in HAP, most frequently from multidrug resistant gram-negative bacteria, and fast accurate diagnosis of etiologic agent(s) of LRTI is essential for an appropriate management. The aim of this retrospective study was to evaluate the analytical performance of Biofire Filmarray Pneumonia Plus for bacteria detection in bronchoalveolar lavage samples and the concordance of bacterial loads between BFPP and cultural gold standard methods. METHODS: A total of 111 BAL samples were obtained from 111 consecutive patients admitted to Intensive Care Unit of "Renato Dulbecco" Teaching Hospital of Catanzaro, from March 2023 to March 2024. RESULTS: Compared to conventional methods, BFPP showed a sensitivity of 99 % and a specificity of 64 %. The agreement between the two methods was assessed by calculating PPA and NPA, being 89 % and 95 %, respectively. The most common bacterial species identified at BFPP was Klebsiella pneumoniae, followed by Acinetobacter calcaceuticus-baumanii complex, Staphylococcus aureus and Pseudomonas aeruginosa. Bacterial load (CFU/ml) in relation to copy number detected by molecular analysis showed the best performance for value ≥10(6) copie/mL. About molecular mechanisms of resistance in comparison to phenotypic profiles, the highest level of performance was observed for presence of KPC genes, all isolates showing resistance to carbapenems, followed by OXA-48 like and NDM. CONCLUSION: The high concordance reported in this study between the identification of resistance genes and phenotypic indication can lead to an appropriate, fast and tailored antibiotic therapy. | 2025 | 40513663 |
| 2486 | 17 | 0.9874 | Virulence-associated genes and antimicrobial resistance patterns in bacteria isolated from pregnant and nonpregnant women with urinary tract infections: the risk of neonatal sepsis. Uropathogenic Escherichia coli (UPEC) is classified as the major causative agent of urinary tract infections (UTIs). UPEC virulence and antibiotic resistance can lead to complications in pregnant women and (or) newborns. Therefore, the aim of this study was to determine the etiological agents of UTIs, as well as to identify genes related to virulence factors in bacteria isolated from pregnant and nonpregnant women. A total of 4506 urine samples were collected from pregnant and nonpregnant women. Urine cultures were performed, and PCR was used to identify phylogroups and virulence-related genes. Antibiotic resistance profiles were determined. The incidence of UTIs was 6.9% (pregnant women, n = 206 and nonpregnant women, n = 57), and UPEC belonging to phylogroup A was the most prevalent. The presence of genes related to capsular protection, adhesins, iron acquisition, and serum protection in UPEC was associated with not being pregnant, while the presence of genes related to adhesins was associated with pregnancy. Bacteria isolated from nonpregnant women were more resistant to antibiotics; 36.5% were multidrug resistant, and 34.9% were extensively drug resistant. Finally, UTIs were associated with neonatal sepsis risk, particularly in pregnant women who underwent cesarean section while having a UTI caused by E. coli. In conclusion, UPEC isolated from nonpregnant women carried more virulence factors than those isolated from pregnant women, and maternal UTIs were associated with neonatal sepsis risk. | 2023 | 37815047 |
| 2508 | 18 | 0.9874 | Genetics of Acquired Antibiotic Resistance Genes in Proteus spp. Proteus spp. are commensal Enterobacterales of the human digestive tract. At the same time, P. mirabilis is commonly involved in urinary tract infections (UTI). P. mirabilis is naturally resistant to several antibiotics including colistin and shows reduced susceptibility to imipenem. However higher levels of resistance to imipenem commonly occur in P. mirabilis isolates consecutively to the loss of porins, reduced expression of penicillin binding proteins (PBPs) PBP1a, PBP2, or acquisition of several antibiotic resistance genes, including carbapenemase genes. In addition, resistance to non-β-lactams is also frequently reported including molecules used for treating UTI infections (e.g., fluoroquinolones, nitrofurans). Emergence and spread of multidrug resistant P. mirabilis isolates, including those producing ESBLs, AmpC cephalosporinases and carbapenemases, are being more and more frequently reported. This review covers Proteus spp. with a focus on the different genetic mechanisms involved in the acquisition of resistance genes to multiple antibiotic classes turning P. mirabilis into a dreadful pandrug resistant bacteria and resulting in difficult to treat infections. | 2020 | 32153540 |
| 2509 | 19 | 0.9874 | Trends in antimicrobial-drug resistance in Japan. Multidrug resistance in gram-positive bacteria has become common worldwide. In Japan until recently, gram-negative bacteria such as Pseudomonas aeruginosa, Klebsiella pneumoniae, and Serratia marcescens were controlled by carbapenems, fluoroquinolones, and aminoglycosides. However, several of these microorganisms have recently developed resistance against many antimicrobial drugs. | 2000 | 11076714 |