Distributions and Types of Multidrug-Resistant Acinetobacter baumannii in Different Departments of a General Hospital. - Related Documents




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219301.0000Distributions and Types of Multidrug-Resistant Acinetobacter baumannii in Different Departments of a General Hospital. BACKGROUND: Acinetobacter baumannii is the most prevalent strain in hospitals and different clinical departments. OBJECTIVES: The current study aimed to investigate the genetic characteristics and resistance mechanisms of A. baumannii isolated from clinical samples in Shaoxing people's hospital affiliated to Zhejiang University, Shaoxing, China. PATIENTS AND METHODS: Acinetobacter baumannii strains were isolated from blood, phlegm and skin of the patients hospitalized in different departments as respiratory medicine, plastic surgery and intensive care unit (ICU). Multilocus sequence typing (MLST) was used to characterize the isolates. Kirby-Bauer test was used to evaluate antibiotic resistance of the bacteria. The expression of resistance inducing genes was detected by reverse transcription polymerase chain reaction (RT-PCR). The results were analyzed and compared. RESULTS: Two bacterial types, ST208, and ST218, were identified in all 140 samples. The ST208 mainly came from ICU and department of respiratory medicine, while ST218 from department of plastic surgery; 70.21% of ST208 and 84.78% of ST218 were carbapenem-resistant Acinetobacter baumannii (CRAB) and carbapenem-susceptible Acinetobacter baumannii (CSAB), respectively. Multidrug-resistance genes in CRAB isolated from the hospital mainly included, oxa-23, oxa-5, intl 1 and qaceΔ1-sul 1. Besides, the highest and lowest antibiotic resistance was observed in the strains isolated from blood samples and wounds, respectively. CONCLUSIONS: The distribution of AB varies in different clinical departments and samples. In the hospital under study, the main types of AB were ST208 and ST218. The genes which affect the ability of antibiotic-resistance were oxa-23, oxa-51, intl 1 and qaceΔ1-sul 1.201526487921
217210.9996Detection of blaPER-1 & blaOxa10 among imipenem resistant isolates of Pseudomonas aeruginosa isolated from burn patients hospitalized in Shiraz Burn Hospital. BACKGROUND AND OBJECTIVES: Pseudomonas aeruginosa is one of the most important Gram negative opportunistic bacteria which causes infection among burn patients. Resistance to the antibiotics in this group of bacteria is increased due to the activity of extended spectrum β-lactamase (ESBLs) genes. In the current study, we investigated the prevalence of two genes (blaPER-1 & blaOxa10 ) related β-lactamase genes among imipenem resistance clinical isolates of P. aeruginosa in hospitalized patients. MATERIALS AND METHODS: From May 2010 to March 2011, 270 P. aeruginosa isolated from hospitalized burned patients' wounds in Shiraz Burn Hospital, were tested for Imipenem resistance by disk diffusion method. Presence of ESBLs exo-enzyme, blaPER-1 and blaOxa10 genes were also evaluated in the resistant isolate. RESULTS: 210 (77.7%) of 270 P. aeruginosa isolates were resistant to imipenem. blaPER-1 and blaOxa10 were detected among 168 (80.0%) of imipenem resistant isolates. Furthermore, 160 (76.2%) of them had blaOxa10 gene and 84 (40.0%) of them had blaPER-1 while 63 (30.0%) resistant isolates contained both genes simultaneously. CONCLUSION: This study showed a high prevalence of blaPER-1 and blaOxa10 genes in hospitalized burn patients in south west of Iran. Therefore, it's highly recommended to perform such tests routinely to evaluate the resistance pattern in order to better antibiotic selection in the burned patients.201526644867
217520.9996Drug-resistant genes carried by Acinetobacter baumanii isolated from patients with lower respiratory tract infection. BACKGROUND: Acinetobacter baumanii (A. baumanii ) remains an important microbial pathogen resulting in nosocomial acquired infections with significant morbidity and mortality. The mechanism by which nosocomial bacteria, like A. baumanii, attain multidrug resistance to antibiotics is of considerable interest. The aim in this study was to investigate the spread status of antibiotic resistance genes, such as multiple β-lactamase genes and aminoglycoside-modifying enzyme genes, from A. baumanii strains isolated from patients with lower respiratory tract infections (LRTIs). METHODS: Two thousand six hundred and ninety-eight sputum or the bronchoalveolar lavage samples from inpatients with LRTIs were collected in 21 hospitals in the mainland of China from November 2007 to February 2009. All samples were routinely inoculated. The isolated bacterial strains and their susceptibility were analyzed via VITEK-2 expert system. Several kinds of antibiotic resistant genes were further differentiated via polymerase chain reaction and sequencing methods. RESULTS: Totally, 39 A. baumanii strains were isolated from 2698 sputum or bronchoalveolar lavage samples. There was not only a high resistant rate of the isolated A. baumanii strains to ampicillin and first- and second-generation cephalosporins (94.87%, 100% and 97.44%, respectively), but also to the third-generation cephalosporins (ceftriaxone at 92.31%, ceftazidine at 51.28%) and imipenem (43.59%) as well. The lowest antibiotic resistance rate of 20.51% was found to amikacin. The OXA-23 gene was identified in 17 strains of A. baumanii, and the AmpC gene in 23 strains. The TEM-1 gene was carried in 15 strains. PER-1 and SHV-2 genes were detected in two different strains. Aminoglycoside-modifying enzyme gene aac-3-Ia was found in 23 strains, and the aac-6'-Ib gene in 19 strains. aac-3-Ia and aac-6'-Ib genes hibernated in three A. baumanii strains that showed no drug-resistant phenotype. CONCLUSIONS: A. baumanii can carry multiple drug-resistant genes at the same time and result in multi-drug resistance. Aminoglycoside-modifying enzyme genes could be hibernating in aminoglycoside sensitive strains without expressing their phenotype.201021034630
92130.9996Evaluation antibiotic resistance and presence of blaOXA-51, blaOXA-58 and blaOXA-23 genes in Acinetobacter baumannii strains via multiplex PCR. The resistance of Acinetobacter baumannii to most antibiotics is increasing. The presence of metallo-beta-lactamase and carbapenemase enzymes has led to the resistance of these bacteria to carbapenems as one of the major classes of broad-spectrum antibiotics and has raised concerns in human societies. This research evaluated the presence of bla(OXA-51), bla(OXA-58) and bla(OXA-23) genes in A. baumannii strains during a 12 months period. One hundred strains were isolated from the patients hospitalized in ICU of Ali Asghar and Shahid Rajaee trauma hospitals in Shiraz. Bacterial identity was determined by biochemical tests and antibiotic resistance was determined by disk diffusion method. The isolated strains were then evaluated in terms of carrying bla(OXA-23), bla(OXA-51) and bla(OXA-58) genes, using the multiplex PCR method. The results showed that A. baumannii was resistant to carbapenems but most strains were susceptible to tigecyclin and colistin. The majority of strains carried the bla(OXA-23) and bla(OXA-51) genes, but very few carried the bla (OXA-58) gene. The results revealed that the antibiotic resistance of A. baumannii is increasing, which causes a more outbreak of this organism.202134803000
222040.9996Rapid detection and molecular survey of blaVIM, blaIMP and blaNDM genes among clinical isolates of Acinetobacter baumannii using new multiplex real-time PCR and melting curve analysis. BACKGROUND: Acinetobacter baumannii is a cosmopolitan bacterium that is frequently reported from hospitalized patients, especially those patients who admitted in the intensive care unit. Recently, multiplex real-time PCR has been introduced for rapid detection of the resistance genes in clinical isolates of bacteria. The current study aimed to develop and evaluate multiplex real-time PCR to detect common resistance genes among clinical isolates of A. baumannii. RESULTS: Multiplex real-time PCR based on melting curve analysis showed different T(m) corresponding to the amplified fragment consisted of 83.5 °C, 93.3 °C and 89.3 °C for blaIMP, blaVIM and blaNDM, respectively. Results of multiplex real-time PCR showed that the prevalence of blaIMP, blaVIM and blaNDM among the clinical isolates of A. baumannii were 5/128(3.9%), 9/128(7.03%) and 0/128(0%), respectively. Multiplex real-time PCR was able to simultaneously identify the resistance genes, while showed 100% concordance with the results of conventional PCR. CONCLUSIONS: The current study showed that blaVIM, was the most prevalent MBL gene among the clinical isolates of A. baumannii while no amplification of blaNDM was seen. Multiplex real-time PCR can be sensitive and reliable technique for rapid detection of resistance genes in clinical isolates.201931182026
92450.9996Screening of Antimicrobial Resistance Genes and Epidemiological Features in Hospital and Community-Associated Carbapenem-Resistant Pseudomonas aeruginosa Infections. INTRODUCTION: Researching carbapenem-resistant isolates enables the identification of carbapenemase-producing bacteria and prevents their spread. METHODS: P. aeruginosa isolates were recovered from Medicine Faculty of Recep Tayyip Erdoğan University and identified by conventional methods and the automated Vitek 2 Compact system. Antimicrobial susceptibility experiments were performed in accordance with CLSI criteria and the automated Vitek 2 Compact system. The PCR method was investigated for the presence of β-lactamase resistance genes. PFGE typing was performed to show clonal relation among samples. RESULTS: Seventy P. aeruginosa isolates were isolated from seventy patients. Of the patients, 67.1% had contact with the health service in the last 90 days and 75.7% of the patients had received antimicrobial therapy in the previous 90 days. Twenty-four isolates were carbapenem resistant, 2 isolates were multidrug-resistant except colistin, and none of the samples had colistin resistance. The gene encoding β-lactamase or metallo-β-lactamase was found in a total of 36 isolates. The bla (VEB) and bla (PER) genes were identified in 1 and 5 isolates alone or 17 and 13 isolates in combination with other resistance genes, respectively. The bla (NDM) was the most detected metallo-β-lactamase encoding gene (n=18), followed by bla (KPC) (n=12). bla (IMP) and bla (VIM) were detected in 5 and 1 isolates, respectively. Also, the association of bla (VEB)-bla (PER) and bla (VEB)-bla (KPC)-bla (NDM) was found to be very high. Much more resistance genes and co-occurrence were detected in hospital-acquired samples than community-acquired samples. No difference was found between the community and hospital-associated isolates according to PFGE results. Simultaneously from 6 patients, other microorganisms were also isolated and 5 of them died. CONCLUSION: The average length of stay (days) was found to be significantly higher in HAI group than CAI group. The death of 5 patients with fewer or no resistance genes showed that the co-existence of other microorganisms in addition to resistance genes was important on death.202133907430
92360.9996Prevalence of Oxacillinase Genes in Clinical Multidrug-Resistant Gram-Negative Bacteria. BACKGROUND: The emergence of OXA-type beta-lactamases has become a significant threat to public healthcare systems and may lead to prolonged hospital stays and increased mortality rates among affected patients. This study aimed to determine the prevalence of oxacillinase resistance (OXA) genes in multidrug-resistant (MDR) Gram-negative bacteria. METHODS: One hundred and six clinical isolates were collected from a stock of Gram-negative isolates and were identified and tested for antibiotic susceptibility and presence of OXA genes using polymerase chain reaction (PCR). RESULTS: The most common detected isolate was Klebsiella pneumoniae (36.8%), followed by Escherichia coli (33%), Pseudomonas aeruginosa (16%), and Acinetobacter baumannii (14.2%). Out of these isolates, 97.4%, 87.2%, 84.6%, and 79.5% were resistant to ampicillin/sulbactam, cefotaxime, ceftazidime, and aztreonam, respectively. PCR results confirmed the presence of one or more OXA genes in 34% of the samples studied. The blaOXA-1 and blaOXA-10 genes were the most highly detected genes, followed by blaOXA-4 and blaOXA-51. The total number of Pseudomonas aeruginosa isolates was confirmed to carry at least one OXA gene (70.6%), whereas Acinetobacter baumannii, Klebsiella pneumoniae, and Escherichia coli were confirmed to carry at least one OXA gene (53.3, 28.2, and 22.9%, respectively). There was a significant association (p < 0.05) between the resistance genes and the type of isolate. CONCLUSIONS: Pseudomonas aeruginosa and Acinetobacter baumannii are the most common MDR Gram-negative strains carrying OXA-type beta-lactamase genes. Monitoring of MDR pathogens in Gram-negative bacteria must be continuously undertaken to implement effective measures for infection control and prevention.202540066541
217470.9995Frequency of Beta-Lactamase Antibiotic Resistance Genes in Escherichia Coli and Klebsiella pneumoniae. BACKGROUND: This cross-sectional study was performed on isolates of Klebsiella pneumoniae, and E.coli from clinical specimens of patients admitted to Sayyad Shirazi Hospital by census sampling method in 2019. Antibiogram testing was performed using the disk diffusion method as defined by the Clinical and Laboratory Standards Organization for performing this test. Finally, the abundance of genes was evaluated by PCR using specific primers. Frequency, percentage, mean±SD were used to describe the data. Chi-square and Fisher's exact tests were used to compare the presence and absence of the studied genes alone and in the presence of each other. RESULT: This study was performed on 130 positive samples, isolated from 32 (24.6%) males and 98 (65.4%) females with a mean age of 43.78 ± 21.72. From the total number of 130 isolates, 84 (64.6%) consisted of E.coli, and 46 (35.4%) were Klebsiella. Most of the cultures were urine and vaginal (61.5%). The highest antibiotic resistance in isolates was cephalexin and cefazolin (67.9% in E.coli & 63% in Klebsiella). Colistin was identified as the most effective antibiotic (100%) in both. AMPC extendedspectrum β-lactamase genes were present in 40 (30.8%) isolates. The highest frequency about the gene pattern of AMPC positive β-lactamase bacteria was correlated to DHA, FOX, and CIT genes, while none of the samples contained the MOX β-lactamase gene. E.coli and Klebsiella beta-lactamase-producing AMPC isolates were also significantly correlated with antibiotic resistance to the cephalosporin class (P <0.05). CONCLUSION: This study indicated a high percentage of resistance to third and fourth generation cephalosporins. Hence, careful antibiogram tests and prevention of antibiotic overuse in infections caused by AMPC-producing organisms and screening of clinical samples for the resistance mentioned above genes and providing effective strategies to help diagnose and apply appropriate treatments and change antibiotic usage strategies can partially prevent the transmission of this resistance.202134483624
220880.9995Evaluation of the relatedness between the biofilm-associated genes and antimicrobial resistance among Acinetobacter baumannii isolates in the southwest Iran. BACKGROUND AND OBJECTIVES: Increasing antimicrobial resistance among Acinetobacter baumannii (A. baumannii) strains poses a significant challenge, particularly in intensive care units (ICUs) where these bacteria are common causes of hospital infections. Biofilm production is recognized as a key mechanism contributing to this resistance. This study aims to explore the relationship between biofilm production, the presence of biofilm-associated genes, and antibiotic resistance patterns in A. baumannii isolates obtained from ICU patients. MATERIALS AND METHODS: We collected 100 A. baumannii isolates from ICU patients at Nemazee Hospital in Shiraz, Iran. Antimicrobial susceptibility testing (AST) was performed using the Kirby-Bauer disk diffusion method, and biofilm production potential was assessed through the tissue culture plate (TCP) method. Additionally, we investigated eleven biofilm-related genes (ompA, bap, csuE, epsA, bla (per-1) , bfmS, pgaB, csgA, fimH, ptk, and kpsMII) in all isolates using polymerase chain reaction (PCR). The REP-PCR technique was utilized to analyze the genetic relatedness of the isolates (Fig. 4). RESULTS: All isolates displayed multi-drug resistance, with the highest resistance rates observed against ceftazidime, cefotaxime, and trimethoprim/sulfamethoxazole (100%). Gentamicin and amikacin showed the lowest resistance rates at 70% and 84%, respectively. A total of 98% of the isolates were capable of biofilm production, with 32% categorized as strong biofilm producers. The most frequently detected biofilm-associated genes included csuE (99%), bfmS (98%), ompA (97%), and pgaB (89%). CONCLUSION: Biofilm production significantly contributes to the prevalence of multi-drug resistant A. baumannii strains. It is essential to implement effective antimicrobial stewardship and develop innovative anti-biofilm strategies to address this global health issue.202540330064
217790.9995Evaluating the Frequency of aac(6')-IIa, ant(2″)-I, intl1, and intl2 Genes in Aminoglycosides Resistant Klebsiella pneumoniae Isolates Obtained from Hospitalized Patients in Yazd, Iran. BACKGROUND: Klebsiella pneumoniae (K. pneumoniae) is an opportunistic pathogen that could be resistant to many antimicrobial agents. Resistance genes can be carried among gram-negative bacteria by integrons. Enzymatic inactivation is the most important mechanism of resistance to aminoglycosides. In this study, the frequencies of two important resistance gene aac(6')-IIa and ant(2″)-I, and genes coding integrase I and II, in K. pneumoniae isolates resistant to aminoglycosides were evaluated. METHODS: In this cross-sectional study, an attempt was made to assess the antibiotic susceptibility of 130 K. pneumoniae isolates obtained from different samples of patients hospitalized in training hospitals of Yazd evaluated by disk diffusion method. The frequencies of aac(6')-IIa, ant(2″)-I, intl1, and intl2 genes were determined by PCR method. Data were analyzed by chi-square method using SPSS software (Ver. 16). RESULTS: our results showed that resistance to gentamicin, tobramycin, kanamycin, and amikacin were 34.6, 33.8, 43.8, and 14.6%, respectively. The frequencies of aac (6')-IIa, ant(2″)-I, intl1, and intl2 genes were 44.6, 27.7, 90, and 0%, respectively. CONCLUSION: This study showed there are high frequencies of genes coding aminoglycosides resistance in K. pneumoniae isolates. Hence, it is very important to monitor and inhibit the spread of antibiotic resistance genes.201829849989
933100.9995Molecular characterization and diversity of carbapenemases in Gram-negative bacteria in Libyan hospitals. INTRODUCTION: Antimicrobial resistance has become a major threat to public health, especially in developing countries, due to the uncontrolled consumption of antibiotics. This study aims to characterize antibiotic resistance genes in different bacteria recovered in different healthcare facilities in Libya. METHODOLOGY: 379 samples were recovered from various sources from different sites. 210 samples were able to grow on culture media. 133 Gram-negative carbapenem-resistant strains were recovered from clinical specimens (n = 64), and hospital environments (n = 69). Antibiotic susceptibility tests were performed to select carbapenem-resistant strains. Colistin resistance was tested by the UMIC method to determine the minimum inhibitory concentration. RT-PCR was conducted to detect the incidence of carbapenemases-encoding genes. RESULTS: Gram-negative bacteria showed a low susceptibility to carbapenems. Molecular investigations indicated that NDM-1 was the most prevalent in Enterobacteriaceae isolated from patients and hospital environment (n = 26, n = 41), followed by blaOXA-48 (n = 16, n = 15) and blaVIM (n = 3) from patients and blaKPC (n = 1) from hospital environment. Concerning A. baumannii, blaOXA-23 was detected in strains isolated from patients (n = 8) and hospital environment (n = 6), followed by blaNDM (n = 9) from patients and one from hospital environment. Carbapenem resistance in P. aeruginosa was encoded by modification in OprD encoding gene, such as IS (ISpa26), polymorphism, and a premature stop codon. CONCLUSIONS: Several carbapenem resistant Gram-negative bacteria were identified by the expression of different carbapenemases and the alteration of OprD.202540720466
2178110.9995Antimicrobial resistance patterns and their encoding genes among clinical isolates of Acinetobacter baumannii in Ahvaz, Southwest Iran. Acinetobacter baumannii is one of the most important organisms in nosocomial infections. Antibiotic resistance in this bacterium causes many problems in treating patients. This study aimed to investigate antibiotic resistance patterns and resistance-related, genes in clinical isolates of Acinetobacter baumannii. This descriptive study was conducted on 124 isolates of Acinetobacter baumannii collected from clinical samples in two teaching hospitals in Ahvaz. The antibiotic resistance pattern was determined by disk diffusion. The presence of genes coding for antibiotic resistance was determined using the polymerase chain reaction method. Out of 124 isolates, the highest rate of resistance was observed for rifampin (96.8%). The resistance rate for imipenem, meropenem, colistin, and polymyxin-B were 78.2%, 73.4%, 0.8% and 0.8%, respectively. The distribution of qnrA, qnrB, qnrS, Tet A, TetB, and Sul1genes were 52.6%, 0%, 3.2%, 93.5% 69.2%, and 6.42%, respectively. High prevalence of tetA, tetB, and qnrA genes among Acinetobacter baumannii isolated strains in this study indicate the important role of these genes in multidrug resistance in this bacteria. • Acinetobacter baumannii is an important human pathogen that has attracted the attention of many researchers Antibiotic resistance in this bacterium causes many problems in treating patients. • The resistance rate for imipenem, meropenem, colistin, and polymyxin-B were 78.2%, 73.4%, 0.8% and 0.8%, respectively. The distribution of qnrA, qnrB, qnrS, Tet A, TetB, and Sul1genes were 52.6%, 0%, 3.2%, 93.5% 69.2%, and 6.42%, respectively.202032983919
931120.9995Epidemiological characteristics and antimicrobial susceptibility among carbapenem-resistant non-fermenting bacteria in Brazil. INTRODUCTION: Non-fermenting Gram-negative bacteria such as Pseudomonas aeruginosa and Acinetobacter baumannii are widespread in the environment and are increasingly associated with nosocomial infections. Extensive and indiscriminate use of antibiotics in hospitals has contributed to an increased number of infections caused by these microorganisms, that are resistant to a wide variety of antimicrobials, including β-lactams. This study aimed to isolate and identify carbapenem-resistant Acinetobacter spp. and P. aeruginosa from hospitalized patients, to determine their antimicrobial susceptibility patterns and to screen for blaOXA-23, blaOXA-24, blaOXA-51, blaOXA-58, and blaOXA-143 genes among the isolated bacteria. METHODOLOGY: Antimicrobial resistance patterns were performed using the disk-diffusion method. Genetic markers related to carbapenem resistance were screened by polymerase chain reaction. RESULTS: Carbapenem-resistant Acinetobacter spp. (n = 44) and P. aeruginosa (n = 28) samples were isolated from patients admitted to a tertiary hospital. Polymyxin B was the only effective drug for all isolates. Considering the oxacillinase gene screening, genetic markers were observed only in Acinetobacter isolates. The most frequent genotype observed was blaOXA-23+/blaOXA-51+ (45.5%), followed by blaOXA-51+/blaOXA-143+ (41%). The oxacillinase genes blaOXA-24 and blaOXA-58 were not detected. High mortality rates (> 70%) were observed. CONCLUSIONS: The data suggest the need for rational use of antimicrobials associated with early diagnosis of multidrug-resistant bacteria, especially considering non-fermenting Gram-negative rods, which are widespread in hospitals. The findings of blaoxa-51(-) strains suggest the occurrence and spread of non-A. baumannii species throughout our hospitals. Effective implementation of surveillance programs in hospitals is needed to reduce infectious and resistant intra- and inter-species bacteria.201627367001
2157130.9995Prevalence and antibiotic resistance pattern of bacteria isolated from urinary tract infections in Northern Iran. BACKGROUND: This study aimed to investigate the bacteria associated with urinary tract infection (UTI) and antibiotic susceptibility pattern of the isolates during 2013-2015 in Northern Iran. MATERIALS AND METHODS: Overall 3798 patients with clinical symptoms of UTI were subjected as samples, and they were cultured and pure isolated bacteria were identified using biochemical tests and subjected to antibiogram assessment using disc diffusion method. RESULTS: Totally, 568 (14.96%) from 3798 patients had positive UTI. Four hundred and ninety-seven (87.5%) from 568 isolated bacteria were resistant to at least one antibiotic. Escherichia coli, Staphylococcus spp., and Pseudomonas spp. were the most prevalent bacteria. Isolated bacteria indicated the highest antibiotic resistance to methicillin (76.06%) and ampicillin (89.29%) and also revealed the most sensitivity to imipenem (99.1%) and amikacin (91.57%). Statistical analysis of the resistance pattern trend during 3 years indicated the insignificant increase (P > 0.05) in antibiotic resistance of the isolates. CONCLUSION: The results of this study revealed a great concern for emerging UTI-related multidrug-resistant strains of bacteria causing UTI in Iran.201729026424
2307140.9995Phenotypic and molecular characterization of antimicrobial resistance and virulence factors in Pseudomonas aeruginosa clinical isolates from Recife, State of Pernambuco, Brazil. INTRODUCTION: The emergence of carbapenem resistance mechanisms in Pseudomonas aeruginosa has been outstanding due to the wide spectrum of antimicrobial degradation of these bacteria, reducing of therapeutic options. METHODS: Sixty-one clinical strains of P. aeruginosa isolated from five public hospitals in Recife, Pernambuco, Brazil, were examined between 2006 and 2010, aiming of evaluating the profiles of virulence, resistance to antimicrobials, presence of metallo-β-lactamase (MBL) genes, and clonal relationship among isolates. RESULTS: A high percentage of virulence factors (34.4% mucoid colonies; 70.5% pyocyanin; 93.4% gelatinase positives; and 72.1% hemolysin positive) and a high percentage of antimicrobial resistance rates (4.9% pan-resistant and 54.1% multi-drug resistant isolates) were observed. Among the 29 isolates resistant to imipenem and/or ceftazidime, 44.8% (13/29) were MBL producers by phenotypic evaluation, and of these, 46.2% (6/13) were positive for the blaSPM-1 gene. The blaIMP and blaVIM genes were not detected. The molecular typing revealed 21 molecular profiles of which seven were detected in distinct hospitals and periods. Among the six positive blaSPM-1 isolates, three presented the same clonal profile and were from the same hospital, whereas the other three presented different clonal profiles. CONCLUSIONS: These results revealed that P. aeruginosa is able to accumulate different resistance and virulence factors, making the treatment of infections difficult. The identification of blaSPM-1 genes and the dissemination of clones in different hospitals, indicate the need for stricter application of infection control measures in hospitals in Recife, Brazil, aiming at reducing costs and damages caused by P. aeruginosa infections.201223295873
936150.9995Occurrence and Diversity of Intra- and Interhospital Drug-Resistant and Biofilm-Forming Acinetobacter baumannii and Pseudomonas aeruginosa. Acinetobacter baumannii and Pseudomonas aeruginosa are the most relevant Gram-negative bacteria associated with hospital and opportunistic infections. This study aimed to evaluate the dynamics of drug-resistant A. baumannii and P. aeruginosa and biofilm formers from two public hospitals in northeastern Brazil. One hundred isolates (35 from A. baumannii and 65 from P. aeruginosa) were identified using the automated Vitek(®)2 Compact method (bioMérieux) and confirmed using the MALDI-TOF (MS) mass spectrometry technique. Molecular experiments were performed by polymerase chain reaction (PCR) to detect the frequency of bla(KPC), bla(IMP), bla(VIM), and bla(SHV) genes. The biofilm formation potential was evaluated using crystal violet in Luria Bertani Miller and trypticase soy broth culture media under the following conditions: at standard concentration, one quarter (25%) of the standard concentration and supplemented with 1% glucose. In addition, the genetic diversity of the isolates was verified by the ERIC-PCR technique. Isolates presented distinct resistance profiles with a high level of beta-lactam resistance. The highest index of genes detected was bla(KPC) (60%), followed by bla(SHV) (39%), bla(VIM) (8%), and bla(IMP) (1%). All the isolates were sensitive to the polymyxins tested and formed biofilms at different intensities. Twelve clones of A. baumannii and eight of P. aeruginosa were identified, of which few were indicative of intra- and interhospital dissemination. This study reveals the dispersion dynamics of these isolates in the hospital environment. The results demonstrate the importance of monitoring programs to combat the spread of these pathogens.202031916896
2165160.9995Distribution and analysis of the resistance profiles of bacteria isolated from blood cultures in the intensive care unit. PURPOSE: To investigate the distribution characteristics and drug resistance of pathogenic bacteria in bloodstream infections, providing a basis for rational clinical treatment. PATIENTS AND METHODS: Retrospective analysis of 1,282 pathogenic strains isolated from blood cultures in the intensive care unit (ICU) of the Second Affiliated Hospital of Xi'an Jiaotong University from January 1, 2019, to December 31, 2022. RESULTS: Gram-positive bacteria (52.0%) slightly predominated over gram-negative bacteria (48.0%). The top three gram-positive bacteria were Coagulase-negative Staphylococcus (28.0%), Enterococcus faecium (7.4%), and Staphylococcus aureus (6.6%). Staphylococci exhibited a high resistance rate to penicillin, oxacillin, and erythromycin; no strains resistant to vancomycin or linezolid were found. Among the Enterococci, Enterococcus faecium had a high resistance rate to penicillin, ampicillin, and erythromycin. Two strains of Enterococcus faecalis were resistant to linezolid, but none to vancomycin. The top three gram-negative bacteria were Escherichia coli (14.7%), Klebsiella pneumoniae (14.0%), and Acinetobacter baumannii (4.8%). The resistance rate of Escherichia coli to carbapenems increased from 0.0 to 2.3%. Acinetobacter baumannii reached 100% carbapenem resistance (up from 75.0%), while Klebsiella pneumoniae demonstrated 21.1-80.4% resistance to various carbapenems. CONCLUSION: The isolation rate of gram-positive bacteria in patients with bloodstream infection in the ICU of the Second Affiliated Hospital of Xi'an Jiaotong University was slightly higher than that of gram-negative bacteria. The alarming carbapenem resistance among gram-negative pathogens and emerging linezolid resistance in Enterococci demand urgent clinical interventions, including enhanced surveillance, antimicrobial stewardship, and novel therapeutic strategies.202540727562
934170.9995High Carbapenem Resistance Caused by VIM and NDM Enzymes and OprD Alteration in Nonfermenter Bacteria Isolated from a Libyan Hospital. Acinetobacter baumannii and Pseudomonas aeruginosa are among the most prevalent pathogens causing a wide range of serious infections in hospitalized patients and contaminating intensive care units and inanimate surfaces. The purpose of this study was to investigate the mechanism of carbapenem resistance in clinical and hospital environmental isolates of A. baumannii and P. aeruginosa recovered from a Libyan hospital. From a total of 82 Gram-negative bacteria, 8 isolates of A. baumannii and 3 isolates of P. aeruginosa exhibited resistance to imipenem with minimum inhibitory concentrations ranging from 16 to >32 μg/mL. Five isolates of A. baumannii harbored bla(OXA-23) gene, from which three isolates were collected from patients and two from hospital environment. Only one isolate harbored bla(NDM-1) gene, which was responsible for carbapenem resistance in A. baumannii. The OprD gene seems to be disturbed by an insertion sequence (IS) in two isolates and affected by polymorphism in one isolate. Pulsed-field gel electrophoresis results showed high genetic diversity among carbapenemase producing A. baumannii. This study highlights the dissemination of bla(OXA-23) and bla(NDM-1) genes in a Libyan setting. Therefore, infection prevention and control practices, antimicrobial stewardship initiatives, and antimicrobial resistance surveillance systems should be implemented to prevent the wide spread of antimicrobial resistance.202134029121
2152180.9995Immunological and molecular detection of biofilm formation and antibiotic resistance genes of Pseudomonas aeruginosa isolated from urinary tract. BACKGROUND AND OBJECTIVES: Pseudomonas aeruginosa (P. aeruginosa) is one of the most common causes of hospital-acquired infections. It is associated with high morbidity and healthcare costs, especially when appropriate antibiotic treatment is delayed. Antibiotic selection for patients with P. aeruginosa infections is challenging due to the bacteria's inherent resistance to many commercially available antibiotics. This study investigated antibiotic-resistance genes in isolated bacteria, which play a key role in disease pathogenesis. MATERIALS AND METHODS: 100 samples out of the 140 samples collected from urinary tract infections (UTIs) cases between December 15(th), 2022, and April 15(th), 2023, were included in the study. Identification of bacterial isolates was based on colony morphology, microscopic examination, biochemical tests, and the Vitek-2 system. Antibiotic resistance genes; Aph(3)-llla, ParC, Tet/tet(M), and aac(6´)-Ib-cr were tested by polymerase chain reaction (PCR). RESULTS: The obtained results were based on bacterial identifications of 81 clinical samples. Only 26 (32%) of these isolates were P. aeruginosa, 21 (26%) were Escherichia coli, and 18 (22.2%) were other bacteria. These isolates were used to detect four genes including tet(M), Aph(3)-llla, Par-c, and aac(6´)-Ib-cr. Four types of primers were used for PCR detection. The results showed that 11/14 (78.57%) carried the tet(M) gene, 10/14 (71.42%) carried the Aph(3)-llla gene, 14/14 (100%) carried the Par-c gene, and 10/14 (71.42%) of the isolates carried the aac(6´)-Ib-cr gene. The biofilm formation examining the esp gene, showed that 9 (64.28) isolates carried this gene. CONCLUSION: The inability of antibiotics to penetrate biofilms is an important factor contributing to the antibiotic tolerance of bacterial biofilms.202540612720
2173190.9995Antimicrobial susceptibility and integrons detection among extended-spectrum β-lactamase producing Enterobacteriaceae isolates in patients with urinary tract infection. BACKGROUND: Integrons are bacterial mobile genetic components responsible for mediating the antibiotic resistance process by carrying and spreading antimicrobial resistance genes among bacteria through horizontal gene transfer. OBJECTIVES: This cross-sectional hospital-based study aimed to find the prevalence of antibiotic resistance patterns and to detect integrons classes (I, II, and III) among bacterial isolates in patients with urinary tract infections (UTI) in Sulaimani, Iraq. PATIENTS AND METHODS: Mid-stream urine samples (no. = 400) were collected from patients with UTI at three different Hospitals from Sulaimani, Iraq, between September 2021 to January 2022. Urine samples were cultured on various agar media, and grown bacteria were isolated. Antibiotic susceptibility test (AST) and an extended-spectrum β-lactamase (ESBL) screen were done for isolated bacteria. Then, integrons classes were screened using conventional PCR with gene sequencing and uploaded to the National Center for Biotechnology Information (NCBI). RESULTS: The frequency rate of Enterobacteriaceae was 67.03% among positive urine cultures. E. coli (no. = 86) and Klebsiella pneumoniae (no. = 32) isolates were identified. The most sensitive antibiotics were the carbapenem group (85.3%) and nitrofurantoin (NFN) (64.2%), while the most resistant antibiotics were nalidixic acid (NA) and 3(rd) generation cephalosporin. The occurrence rate of ESBL was 56.6% with a predominance of class I integron (54.2%), then class II (15.8%) and no positive record for class III integron were observed. CONCLUSION: Most bacterial isolates from patients with UTI produced class I and II integrons genes with favourable ESBL properties.202337283901