Evaluated gene expressions of Metallo beta lactamase genes GIM and , VIM, SPM in Pseudomonas aeruginosa clinical isolates. - Related Documents




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231301.0000Evaluated gene expressions of Metallo beta lactamase genes GIM and , VIM, SPM in Pseudomonas aeruginosa clinical isolates. Pseudomonas aeruginosa is considered as one of the human health care problems, P. aeruginosa's carbapenem resistance emerges by several different mechanisms, some of which include carbapenems genes. P. aeruginosa's carbapenem resistance is a significant health concern, So this study aims to evaluate MBL gene expressions. The study was conducted at the Department of Microbiology, AL-Mahmoodia Hospital, over one year from January to December 2022. The samples were collected from patients with different clinical sources (Burn, Urine, Wound, Sputum, Ear, and Blood), from different ages while. Samples were collected from three hospitals in Baghdad including Al-Yarmouk Teaching Hospital, AL-Mahmmodiya Hospital, and Child's Central Teaching Hospital. A study analyzed 55 P. aeruginosa strains from various clinical sources, the study utilizes the chemical characterization, VITEK 2 system, 16s rRNA, antibiogram sensitivity tests, antibiotic susceptibility using eight antibiotics, including Amikacin, Ciprofloxacin, Levofloxacin, Imipenem Meropenem, Piperacillin, Cefepim and Aztreonam. The test of bacterial susceptibility revealed that each isolate was highly resistant to piperacillin, which are 96.36%, and lower resistance to Ciprofloxacin, which are 32%. Phenotypic screening carbapenem resistance methods combined the disk synergy test and conventional PCR that were used to detect isolates by using 16 S rRNA. This proves that the bacteria is P. aeruginosa and computed by measuring gene expression of the target genes (GIM, VIM, SPM) by using the real-time PCR, which is employed for twenty-five isolates. The result indicates that the expression level of the VIM gene is highly regulated in carbapenem-resistance isolates compared to control isolates that is 1.00. While the expression level of gene GIM and SPM is downregulated in carbapenem-resistance isolates compared to control isolates that is 6. The carbapenem VIM and GIM, SPM (class B) genes are essential for resistance in P. aeruginosa induced by chromosomal changes that modify membrane permeability efflux pump overexpression for genes. As a result, many studies require for discovering new strategies to reduce the threat to public health through preventing the spread of these isolates via tight infections, control measures, and the reduction of the danger to public health.202337917414
230810.9999Trends of Antibiotic Resistance in Multidrug-Resistant Pathogens Isolated from Blood Cultures in a Four-Year Period. BACKGROUND: Multidrug-resistant organisms cause serious infections with significant morbidity and mortality in the worldwide. These organisms have been identified as urgent and serious threats by CDC. The aim of this study was to determine the prevalence and changes of antibiotic resistance of multidrug-resistant pathogens isolated from blood cultures over a four-year period in a tertiary-care hospital. METHODS: Blood cultures were incubated in a blood culture system. Positive signalling blood cultures were subcultured on 5% sheep-blood agar. Identification of isolated bacteria was performed using conventional or automated identification systems. Antibiotic susceptibility tests were performed by disc diffusion and/or gradient test methods, if necessary, by automated systems. The CLSI guidelines were used for interpretation of antibiotic susceptibility testing of bacteria. RESULTS: The most frequently isolated Gram-negative bacteria was Escherichia coli (33.4%) followed by Klebsiella pneumoniae (21.5%). ESBL positivity was 47% for E. coli, 66% for K. pneumoniae. Among E. coli, K. pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii isolates, carbapenem resistance was 4%, 41%, 37%, and 62%, respectively. Carbapenem resistance of K. pneumoniae isolates has increased from 25% to 57% over the years, and the highest rate (57%) occured during the pandemic period. It is noteworthy that the aminoglycoside resistance in E. coli isolates gradually increased from 2017 to 2021. The rate of methicillin-resistant S. aureus (MRSA) was found to be 35.5%. CONCLUSIONS: Increased carbapenem resistance in K. pneumoniae and A. baumannii isolates is noteworthy, but carbapenem resistance in P. aeruginosa decreased. It is of great importance for each hospital to monitor the increase in resistance in clinically important bacteria, especially isolated from invasive samples, in order to take the necessary precautions in a timely manner. Future studies involving clinical data of patients and bacterial resistance genes are warranted.202337307126
167620.9999Evaluation of carbapenem resistance using phenotypic and genotypic techniques in Enterobacteriaceae isolates. BACKGROUND: Bacterial resistance to antibiotics is increasing worldwide. Antibiotic-resistant strains can lead to serious problems regarding treatment of infection. Carbapenem antibiotics are the final treatment option for infections caused by serious and life-threatening multidrug-resistant gram-negative bacteria. Therefore, an understanding of carbapenem resistance is important for infection control. In the study described herein, the phenotypic and genotypic features of carbapenem-resistant Enterobacteriaceae strains isolated in our hospital were evaluated. METHODS: In total, 43 carbapenem-resistant strains were included in this study. Sensitivity to antibiotics was determined using the VITEK(®)2 system. The modified Hodge test (MHT) and metallo-β-lactamase (MBL) antimicrobial gradient test were performed for phenotypic identification. Resistance genes IMP, VIM, KPC, NDM-1, and OXA-48 were amplified by multiplex PCR. RESULTS: The OXA-48 gene was detected in seven strains, and the NDM-1 gene in one strain. No resistance genes were detected in the remainder of strains. A significant correlation was observed between the MHT test and OXA-48 positivity, and between the MBL antimicrobial gradient test and positivity for resistance genes (p < 0.05). CONCLUSION: The finding of one NDM-1-positive isolate in this study indicates that carbapenem resistance is spreading in Turkey. Carbapenem resistance spreads rapidly and causes challenges in treatment, and results in high mortality/morbidity rates. Therefore, is necessary to determine carbapenem resistance in Enterobacteriaceae isolates and to take essential infection control precautions to avoid spread of this resistance.201526444537
230730.9998Phenotypic 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
93540.9998Evaluating the Saliva of Burn ICU Patients for Resistant Infections Harbor Metallo-β-Lactamase Genes. Pseudomonas aeruginosa and Acinetobacter baumannii are the bacteria which increasingly account for nosocomial infections. Due to high virulence, the rate of Multi-Drug Resistance (MDR) and limited availability of new agents, these infections create significant clinical burdens, making it important to identify the possible sources of their occurrence. The aim of this study was to assess non-lactose fermenting bacteria and their metallo-β-lactamase (MBLs) genes expression in the Burn Intensive Care Unit (BICU) patients' saliva samples. This cross-sectional study was conducted from 2017 to 2018 on 124 saliva samples of BICU patients. Identified isolates were evaluated for drug susceptibility by disc diffusion method. MBLs production isolates were detected by Modified Hodge test and Imipenem-EDTA Combined disk. MBLs related genes were evaluated by polymerase chain reaction (PCR). A total of 86 Gram negative non-lactose fermenting bacteria (38; A. baumannii) and (48; P. aeruginosa), were detected. All of the A. baumannii isolates were resistant to Carbapenems, while more than 90% of them were sensitive to Colistin. However, the highest sensitivity in P. aeruginosa isolates was related to Carbapenems and Colistin. More than 95% of A. baumannii and 32% of P. aeruginosa were detected MDR. MBLs production was confirmed in 9 (33.33%) P. aeruginosa and 18 (66.67%) A. baumannii isolates. The blaVIM was the most prevalent gene, while this gene was detected in all of MBLs positive strains. This study confirmed the prevalence of carbapenemase producer Gram-negative bacilli in the saliva of BICU patients. The results of the present study provide a new data set about saliva infection source that could lead to the proper antibiotic regimen and better control of drug resistance.202031930340
225350.9998Biofilm Formation and Antibiotic Resistance Profiles in Carbapenemase-Producing Gram-Negative Rods-A Comparative Analysis between Screening and Pathological Isolates. (1) Background: Carbapenem-resistant (CR) bacteria pose a significant global public health challenge due to their ability to evade treatment with beta-lactam antibiotics, including carbapenems. This study investigates the biofilm-forming capabilities of CR clinical bacterial isolates and examines the impact of serum on biofilm formation. Additionally, the study evaluates the resistance profiles and genetic markers for carbapenemase production. (2) Methods: Bacterial isolates were collected from the microbiology laboratory of Mures County Clinical Hospital between October 2022 and September 2023. Pharyngeal and rectal swabs were screened for carbapenem-resistant bacteria using selective media. Lower respiratory tract samples were also analyzed for CR Gram-negative bacteria. The isolates were tested for their ability to form biofilms in the presence and absence of fetal bovine serum at 24 and 48 h. Carbapenemase production was detected phenotypically and confirmed via PCR for relevant genes. (3) Results: Out of 846 screened samples, 4.25% from pharyngeal swabs and 6.38% from rectal swabs tested positive for CR bacteria. Acinetobacter baumannii and Klebsiella pneumoniae were the most common species isolated. Biofilm formation varied significantly between clinical isolates and standard strains, with clinical isolates generally showing higher biofilm production. The presence of serum had no significant effect on biofilm formation in Klebsiella spp., but stimulated biofilm formation for Acinetobacter spp. Carbapenemase genes bla(KPC), bla(OXA-48-like), and bla(NDM) were detected in various isolates, predominantly in Klebsiella spp., but were not the main determinants of carbapenem resistance, at least in screening isolates. (4) Conclusions: This study highlights the variability in biofilm formation among CR clinical isolates and underscores the differences between the bacteria found as carriage versus infection. Both bacterial species and environmental factors variably influence biofilm formation. These insights are crucial for the development of effective treatment and infection control strategies in clinical settings.202439199988
230960.9998Antimicrobial Resistance Patterns of Pathogens Isolated from Patients with Wound Infection at a Teaching Hospital in Vietnam. PURPOSE: At a teaching Hospital in Vietnam, the persistently high incidence of diagnosed wound infection poses ongoing challenges to treatment. This study seeks to explore the causative agents of wound infection and their antimicrobial and multidrug resistance patterns. METHODS: A cross-sectional study was conducted at the Department of Microbiology, Military Hospital 103, Vietnam. Data on microorganisms that caused wound infection and their antimicrobial resistance patterns was recorded from hospitalized patients from 2014 to 2021. Using the chi-square test, we analyzed the initial isolation from wound infection specimens collected from individual patients. RESULTS: Over a third (34.9%) of wound infection samples yielded bacterial cultures. Staphylococcus aureus was the most prevalent bacteria, followed by Pseudomonas aeruginosa. Worryingly high resistance rates were observed for several antibiotics, particularly among Gram-negative bacteria. Ampicillin displayed the highest resistance (91.9%), while colistin and ertapenem remained the most effective. In Gram-positive bacteria, glycopeptides like teicoplanin and vancomycin (0% and 3.3% resistance, respectively) were most effective, but their use was limited. Clindamycin and tetracycline showed decreasing effectiveness. Resistance rates differed between surgical and non-surgical wards, highlighting the complex dynamics of antimicrobial resistance within hospitals. Multidrug resistance (MDR) was substantial, with Gram-negative bacteria exhibiting a 63.6% MDR rate. Acinetobacter baumannii showed the highest MDR rate (88.0%). CONCLUSION: This study investigated wound infection characteristics, antibiotic resistance patterns of common bacteria, and variations by hospital ward. S. aureus was the most prevalent bacteria, and concerning resistance rates were observed, particularly among Gram-negative bacteria. These findings highlight the prevalence of multidrug resistance in wound infections, emphasizing the importance of infection control measures and judicious antibiotic use.202439139624
93170.9998Epidemiological 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
231280.9998Metallo-beta-Lactamase VIM-1, SPM-1, and IMP-1 Genes Among Clinical Pseudomonas aeruginosa Species Isolated in Zahedan, Iran. BACKGROUND: One of the major clinical problems regarding Pseudomonas aeruginosa is attributed to metallo-beta-lactamases (MBL). This group of enzymes is a subset of beta lactamases which belong to group B of Ambler classification and cause hydrolysis of carbapenems. Based on epidemiological studies conducted worldwide, it is proved that prevalence of genes coding MBLs in P. aeruginosa species are different in various geographic zones and even in various hospitals. Therefore, according to the clinical importance of organisms generating MBLs, it is necessary to identify and control these bacteria in hospitals for therapeutic purposes. OBJECTIVES: The current study aimed to investigate the Metallo-beta-Lactamase VIM-1, SPM-1, and IMP-1 genes among clinical P. aeruginosa species isolated in Zahedan, Iran. MATERIALS AND METHODS: The current study investigated the presence of MBL through phenotypic and genotypic methods and also the pattern of antibiotic resistance in P. aeruginosa species isolated in hospitals. The Minimum Inhibitory Concentration (MIC) against imipeneme was measured for 191 P. aeruginosa species isolated from Zahedan hospitals after identification through biochemical methods and determination of the antibiotic resistance pattern. Strains with MIC > 4 µg/mL were studied by phenotypic and genotypic methods. RESULTS: The rate of resistance against imipeneme was 5.7% and after carrying out the phenotypic experiments, nine species were identified as of MBL producer. Seven species were confirmed by Polymerase Chain Reaction (PCR) method. Gene VIM-1 was the predominant gene among the positive (antibiotic resistant) species. CONCLUSIONS: The study results showed that MBL genes were present in some of the species isolated from Zahedan hospitals. Regarding the importance of MBL producer bacteria in hospitals, quick identification and evaluation of these clinical species can be considered as an important and basic step for treatment and control of pseudomonad infections.201526034547
225290.9998Antimicrobial resistance of 3 types of gram-negative bacteria isolated from hospital surfaces and the hands of health care workers. BACKGROUND: There has been an increased focus in recent years on antimicrobial resistance of bacteria isolated from clinical samples. However, resistance of bacteria from hospital environments has been less frequently investigated. METHODS: According to hygienic standard for disinfection in hospitals, samples were collected from hospital inanimate surfaces and the hands of health care workers after daily cleaning. An automatic microorganism analyzer was used to identify bacteria and test for antimicrobial susceptibility. Polymerase chain reaction was used to detect antimicrobial resistance genes. RESULTS: The detection rate of bacteria in general wards was significantly higher than that in intensive care units. The isolates were predominantly gram-negative (GN) bacteria, with Pseudomonas aeruginosa, Enterobacter cloacae, and Klebsiella pneumoniae being the most common. P aeruginosa isolates from other surfaces were much higher than those from medical instruments. E cloacae was isolated more frequently from the hands of other staff than medical staff. Most P aeruginosa and K pneumoniae were resistant to sulfonamides and β-lactam antimicrobials. Only 1 strain of P aeruginosa and 1 strain of K pneumoniae showed multiple antimicrobials resistance. CONCLUSIONS: The GN bacteria isolated from hospital environments demonstrate variable resistance to antimicrobials.201728780198
858100.9998Minocycline and Omadacycline Resistance Among Carbapenem-Resistant Gram-Negative Bacteria: Antimicrobial Susceptibility Testing and Molecular Characterization. Increasing prevalence of multidrug-resistant infections has rendered the healthcare systems ineffective in managing infectious diseases. Drugs of "last resort" like carbapenems and polymyxins are becoming less effective in the management of antibiotic-resistant Gram-negative bacterial infections, leaving the clinicians with limited choices. Evaluation of the efficacy of other available broad-spectrum antibiotics (belonging to a different class) is warranted as a treatment alternative. The current study was undertaken to evaluate the in vitro antibacterial activity of minocycline and a new drug, omadacycline among carbapenem-resistant Gram-negative bacteria (GNB), isolated from clinical samples (pus and sputum) and to genotypically analyze them. A prospective cross-sectional study was conducted in a 3,200-bedded tertiary care medical center, located in Lucknow in the northern part of India. All the clinical isolates recovered from pus and sputum samples of patients admitted in intensive care units were processed according to the standard protocols. Identification and antibiotic susceptibility testing were performed, and carbapenem-resistant Gram-negative bacteria (CRGNB) showing resistance to minocycline were included in the study. Molecular screening of β-lactamase and tetracycline resistance genes was done by the conventional polymerase chain reaction method. Minimum inhibitory concentration analysis was performed using the broth microdilution technique. Among 700 CRGNB, 15.29% (n = 107/700) were minocycline resistant by disk diffusion method. Genetic analysis demonstrated the presence of tetracycline-resistant genes in about one-third isolates, among which the tet(B) gene was present in 41.12% (n = 44/107). Upon broth microdilution analysis, the overall minimum inhibitory concentration for minocycline was raised, wherein 4.76% (n = 5/107) of our clinical Gram-negative isolates were inhibited at ≤8 mg/L and 15.23% (n = 28/107) were inhibited at ≤16 mg/L. Omadacycline was able to inhibit 13.08% (n = 14/107) of the minocycline-resistant isolates at ≤4 mg/L (susceptible breakpoint for Enterobacterales). Based on the cut-off value proposed, 15.09% (n = 16/107) isolates resistant to minocycline were inhibited by omadacycline. High prevalence of multidrug-resistant bugs entails judicious use of minocycline and omadacycline. The presence of tet genes coexisting with bla(NDM) and bla(OXA) in our bacterial isolates shows that the resistance pattern in Gram-negative bacilli is regularly evolving, and a fully functional surveillance program across the health care system is needed to prevent the emergence and spread of antimicrobial resistance.202540126171
2317110.9998Molecular Detection of Adefg Efflux Pump Genes and their Contribution to Antibiotic Resistance in Acinetobacter baumannii Clinical Isolates. BACKGROUND: Acinetobacter baumannii (A. baumannii) is one of the most important bacteria causing nosocomial infections worldwide. Over the past few years, several strains of A. baumannii have shown antibiotic resistance, which may be due to the activity of efflux pumps. This study was aimed to detect AdeFG efflux pump genes and their contribution to antibiotic resistance in A. baumannii clinical isolates. METHODS: A total of 200 A. baumannii clinical isolates were collected from clinical specimens of ulcers, pus, sputum, and blood. All isolates were identified using standard biochemical tests. After identifying and cleaving the genome by boiling, PCR was performed on samples using specific primers. The antimicrobial susceptibility patterns were determined by disk diffusion, with and without CCCP efflux pump inhibitor were determined according to CLSI guidelines. RESULTS: We identified 60 clinical isolates of A. baumannii using biochemical differential tests. Identification of all A. baumannii isolates was confirmed by blaOXA-51-like PCR. According to the results of our study, 98.37% of A. baumannii isolates were resistant to ciprofloxacin, norfloxacin, and levofloxacin. PCR results indicated that all 60 A. baumannii isolates contained the AdeF and 76.66% contained AdeG. CONCLUSION: the results of this study demonstrated that most of the A. baumannii isolates contained AdeF and AdeG efflux pump genes, and more than 98% of the isolates were resistant to ciprofloxacin, norfloxacin, and levofloxacin. This reflected the significant contribution of efflux pumps to the development of resistance to these antibiotics.202032582800
2303120.9998Patterns of Drug-Resistant Bacteria in a General Hospital, China, 2011-2016. Drug-resistant bacteria has been a threat to public life and property. We described the trends and changes in antibiotic resistance of important pathogens in a general hospital in Zhengzhou, China from 2011 to 2016, to control antimicrobial-resistant bacteria in hospital and provide support to clinicians and decision-making departments. Five dominant bacteria were enrolled based on the data from the general hospital during 6 years. The results of antimicrobial susceptibility testing were interpreted according to Clinical and Laboratory Standards Institute (CLSI). From 2011 to 2016, a total of 19,260 strains of bacteria were isolated, of which Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Acinetobacter baumannii accounted for 51.98%. The resistance rate of K. pneumoniae and E. coli to carbapenem was less than 15%, but resistance of K. pneumoniae to carbapenems increased with time and resistance of E. coli to meropenem increased. The rate of extended-spectrum beta-lactamase (ESBL) production among K. pneumoniae and E. coli was decreasing. For most antibiotics, the resistance rate of ESBL-positive isolates was higher than that of ESBL-negative isolates, excluding carbapenems and cefoxitin. For S. aureus, the rate of methicillin-resistant S. aureus (MRSA) was stable. Resistance of S. aureus to mostly antibiotics decreased with time. Besides polymyxin B, P. aeruginosa and A. baumannii showed high resistance to other antibiotics. For A. baumannii, the resistance rate to mostly antibiotics was increasing. The bacteria showed high levels of resistance and multiple drug resistance. Continuous surveillance and optimizing the use of antibiotics are essential. Drug-resistant bacteria has been a threat to public life and property. We described the trends and changes in antibiotic resistance of important pathogens in a general hospital in Zhengzhou, China from 2011 to 2016, to control antimicrobial-resistant bacteria in hospital and provide support to clinicians and decision-making departments. Five dominant bacteria were enrolled based on the data from the general hospital during 6 years. The results of antimicrobial susceptibility testing were interpreted according to Clinical and Laboratory Standards Institute (CLSI). From 2011 to 2016, a total of 19,260 strains of bacteria were isolated, of which Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Acinetobacter baumannii accounted for 51.98%. The resistance rate of K. pneumoniae and E. coli to carbapenem was less than 15%, but resistance of K. pneumoniae to carbapenems increased with time and resistance of E. coli to meropenem increased. The rate of extended-spectrum beta-lactamase (ESBL) production among K. pneumoniae and E. coli was decreasing. For most antibiotics, the resistance rate of ESBL-positive isolates was higher than that of ESBL-negative isolates, excluding carbapenems and cefoxitin. For S. aureus, the rate of methicillin-resistant S. aureus (MRSA) was stable. Resistance of S. aureus to mostly antibiotics decreased with time. Besides polymyxin B, P. aeruginosa and A. baumannii showed high resistance to other antibiotics. For A. baumannii, the resistance rate to mostly antibiotics was increasing. The bacteria showed high levels of resistance and multiple drug resistance. Continuous surveillance and optimizing the use of antibiotics are essential.201931250593
1675130.9998Phenotypic and genetic extended spectrum beta lactamase profiles of bacterial isolates from ICU in tertiary level hospital in Kenya. BACKGROUND: Bacterial infections in the Intensive Care Units are a threat to the lives of critically ill patients. Their vulnerable immunity predisposes them to developing bacteria-associated sepsis, deteriorating their already fragile health. In the face of increasing antibiotics resistance, the problem of bacterial infection in ICU is worsening. Surveillance of bacterial infections in ICUs and drug resistance will help to understand the magnitude of the problem it poses and inform response strategies. We assessed bacterial infections in ICU setting by identifying prevalent Gram-negative bacterial species and characterized their antibiotic susceptibility patterns. METHODS: Cross-sectional samples collected from Kenyatta National Hospital ICU between January and June 2021 were cultured and phenotypic identification of culture-positive samples performed using VITEK 2. Antibiotic susceptibility patterns were determined based on Antimicrobial Susceptibility Testing (AST) results. Cephalosporin-resistant Gram-negative bacteria were assessed by PCR to detect the presence of ESBL genes including ( (bla) CTX-M, (bla) SHV, (bla) TEM, (bla) OXA). RESULTS AND DISCUSSION: Out of the 168 Gram-negative isolates, Acinetobacter baumanii was the most abundant (35%). Other isolates that were present at frequencies more than 15% are Klebsiella pneumoniae and Escherichia. coli. A. baumaniii is known to be a notorious bacterium in ICU due to its multidrug resistance nature. Indeed, A. baumanii isolates from Kenyatta National Hospital showed significantly high level of phenotypic resistance. Concordant with the high level of phenotypic resistance, we found high carriage of the ESBL genes among the isolates analysed in this study. Moreover, majority of isolates harboured all the four ESBL genes. CONCLUSION: A high rate of phenotypic and genetic resistance was detected among the tested isolates. Resistance to cephalosporins was primarily driven by acquisition of the ESBL genes. The high prevalence rate of ESBL genes in ICU bacterial isolates shown in this study has a important implication for ICU patient management and general antibiotics use.202339850338
936140.9998Occurrence 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
2255150.9998Diversity and metallo-β-lactamase-producing genes in Pseudomonas aeruginosa strains isolated from filters of household water treatment systems. The microbiological quality of drinking water has long been a critical element in public health. Considering the high clinical relevance of Pseudomonas aeruginosa, we examined the filters of household water treatment systems for its presence and characteristics to determine the systems' efficiency in eliminating the bacteria. In total, filters of 50 household water treatment systems were examined. Microbiological and molecular methods were used for the detection and confirmation of P. aeruginosa isolates. Random Amplification of Polymorphic DNA-polymerase chain reaction (RAPD-PCR) was performed to detect similarities and differences among P. aeruginosa isolates. Combined disk (CD) method and double disk synergy test (DDST) were performed to detect metallo-beta-lactamase (MBL)-producing P. aeruginosa isolates. Finally, PCR was performed to detect MBL genes in MBL-producing strains. From the 50 analyzed systems, 76 colonies of P. aeruginosa were identified. In some systems, isolated bacteria from different filters harbored similar genetic profiles, indicating that these isolates may be able to pass through the filter and reach higher filters of the system. Phenotypic tests revealed 7 (9.2%) MBL-producing strains. Two isolates were positive for bla(VIM-1), whereas one isolate was positive for bla(NDM) and bla(IMP-1). The wide distribution of resistant phenotypes and genetic plasticity of these bacteria in household water treatment systems indicate that resistance mechanisms circulate among P. aeruginosa isolates in the environment of the filtration systems. The presence of MBL-producing genes in these systems and P. aeruginosa as a potential reservoir of these resistance genes can be a major concern for public health.201930368151
2304160.9998Antimicrobial consumption and resistance in five Gram-negative bacterial species in a hospital from 2003 to 2011. BACKGROUND: The misuse of antimicrobial agents increases drug resistance in bacteria. METHODS: The correlation between antimicrobial agent consumption and related resistance in the Gram-negative bacteria Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Proteus mirabilis was analyzed during the period 2003-2011. RESULTS: Among these five bacteria, overall E. coli and K. pneumoniae were more commonly isolated from bloodstream than the other species. Regarding Enterobacteriaceae, E. coli and K. pneumoniae showed annual increases of resistance to the tested antimicrobial agents; conversely, P. mirabilis exhibited reduced resistance to cefuroxime, ceftriaxone and cefepime. In contrast to the relatively low antimicrobial resistance in P. aeruginosa, A. baumannii revealed high resistance, which was over 85% resistant rate to the tested antimicrobial agents and over 80% carbapenem resistance in 2011. E. coli, K. pneumoniae, and P. mirabilis differed in development of antimicrobial resistance after consumption of the antimicrobial agents. K. pneumoniae developed resistance to all antimicrobial groups, whereas resistance in P. mirabilis was not related to any antimicrobial consumption. P. aeruginosa developed resistance to β-lactam antimicrobials and aminoglycosides, whereas A. baumanii developed resistance to carbapenems after their use. CONCLUSION: The development of antimicrobial resistance was related to antimicrobial agents and bacterial species.201524863496
865170.9998High Prevalence of bla(NDM-1), bla(VIM), qacE, and qacEΔ1 Genes and Their Association with Decreased Susceptibility to Antibiotics and Common Hospital Biocides in Clinical Isolates of Acinetobacter baumannii. The objective of this study was to evaluate the susceptibility of metallo-β-lactamase (MBL)-producing Acinetobacter baumannii (A. baumannii) clinical isolates to biocides. We also determined the prevalence and correlation of efflux pump genes, class 1 integron and MBL encoding genes. In addition, bla(VIM), bla(NDM-1), qacE and qacEΔ1 nucleotide sequence analysis was performed and compared to sequences retrieved from GenBank at the National Center for Biotechnology Information database. A. baumannii had a resistance rate to carbapenem of 71.4% and 39.3% and was found to be a MBL producer. The minimum inhibitory concentrations (MICs) of chlorhexidine and cetrimide were higher than the recommended concentrations for disinfection in 54.5% and 77.3% of MBL-positive isolates respectively and their MICs were significantly higher among qac gene-positive isolates. Coexistence of qac genes was detected in 68.1% and 50% of the isolates with bla(VIM) and bla(NDM-1) respectively. There was a significant correlation between the presence of qac genes and MBL-encoding bla(VIM) and bla(NDM-1) genes. Each of the bla(NDM-1), bla(VIM), qacE and qacEΔ1 DNA sequences showed homology with each other and with similar sequences reported from other countries. The high incidence of Verona integron-encoded metallo-β-lactamases (VIM) and New-Delhi-metallo-β-lactamase (NDM) and qac genes in A.baumannii highlights emerging therapeutic challenges for being readily transferable between clinically relevant bacteria. In addition reduced susceptibility to chlorhexidine and cetrimide and the potential for cross resistance to some antibiotics necessitates the urgent need for healthcare facilities to periodically evaluate biocides efficacy, to address the issue of antiseptic resistance and to initiate a "biocidal stewardship".201728417918
2228180.9998Accurate Detection of the Four Most Prevalent Carbapenemases in E. coli and K. pneumoniae by High-Resolution Mass Spectrometry. BACKGROUND: At present, phenotypic growth inhibition techniques are used in routine diagnostic microbiology to determine antimicrobial resistance of bacteria. Molecular techniques such as PCR are often used for confirmation but are indirect as they detect particular resistance genes. A direct technique would be able to detect the proteins of the resistance mechanism itself. In the present study targeted high resolution mass spectrometry assay was developed for the simultaneous detection of KPC, OXA-48-like, NDM, and VIM carbapenemases. METHODS: Carbapenemase specific target peptides were defined by comparing available sequences in GenBank. Selected peptide sequences were validated using 62 Klebsiella pneumoniae and Escherichia coli isolates containing: 16 KPC, 21 OXA-48-like, 16 NDM, 13 VIM genes, and 21 carbapenemase negative isolates. RESULTS: For each carbapenemase, two candidate peptides were validated. Method validation was performed in a blinded manner for all 83 isolates. All carbapenemases were detected. The majority was detected by both target peptides. All target peptides were 100% specific in the tested isolates and no peptide carry-over was detected. CONCLUSION: The applied targeted bottom-up mass spectrometry technique is able to accurately detect the four most prevalent carbapenemases in a single analysis.201931849899
874190.9998Prevalence of Carbapenem Resistance Genes among Acinetobacter baumannii Isolated from a Teaching Hospital in Taiwan. The problem of antibiotic-resistant strains has become a global public issue; antibiotic resistance not only limits the choice of treatments but also increases morbidity, mortality and treatment costs. The multi-drug resistant Acinetobacter baumannii is occurring simultaneously in hospitals and has become a major public health issue worldwide. Although many medical units have begun to control the use of antibiotics and paid attention to the issue of drug resistance, understanding the transmission pathways of clinical drug-resistant bacteria and drug-resistant mechanisms can be effective in real-time control and prevent the outbreak of antibiotic-resistant pathogens. In this study, a total of 154 isolates of Acinetobacter baumannii obtained from Chia-Yi Christian Hospital in Taiwan were collected for specific resistance genotyping analysis. Ten genes related to drug resistance, including blaOXA-51-like, blaOXA-23-like, blaOXA-58-like, blaOXA-24-like, blaOXA-143-like, tnpA, ISAba1, blaPER-1, blaNDM and blaADC, and the repetitive element (ERIC2) were selected for genotyping analysis. The results revealed that 135 A. baumannii isolates (87.6%) carried the blaOXA-51-like gene, 4.5% of the isolates harbored the blaOXA-23-like gene, and 3.2% of the isolates carried the blaOXA-58-like gene. However, neither the blaOXA-24-like nor blaOXA-143-like genes were detected in the isolates. Analysis of ESBL-producing strains revealed that blaNDM was not found in the test strains, but 38.3% of the test isolates carried blaPER-1. In addition, blaADC, tnpA and ISAba1genes were found in 64.9%, 74% and 93% of the isolates, respectively. Among the carbapenem-resistant strains of A. baumannii, 68% of the isolates presenting a higher antibiotic resistance carried both tnpA and ISAba1 genes. Analysis of the relationship between their phenotypes (antibiotic resistant and biofilm formation) and genotypes (antibiotic-resistant genes and biofilm-related genes) studied indicated that the bap, ompA, ISAba1and blaOXA-51 genes influenced biofilm formation and antibiotic resistance patterns based on the statistical results of a hierarchical clustering dendrogram. The analysis of the antibiotic-resistant mechanism provides valuable information for the screening, identification, diagnosis, treatment and control of clinical antibiotic-resistant pathogens, and is an important reference pointer to prevent strains from producing resistance.202337760654