جستجوی مقالات مرتبط با کلیدواژه « Acinetobacter baumannii » در نشریات گروه « پزشکی »

To explore the prevalence and characteristics of secondary bacterial infections among patients suffering from mucormycosis following COVID-19 infection.

We conducted a cross-sectional, retrospective analysis from March 2020 to April 2022 at Imam Khomeini Hospital Complex in Tehran. The study included patients with histopathologically confirmed mucormycosis and documented secondary bacterial infections. We extracted and analyzed data from hospital records using SPSS software, version 26.

The study comprised 27 patients, with a predominance of females (70.4%) and an average age of 56 years. The majority of these patients (63%) had pre-existing diabetes mellitus. The severity of their COVID-19 infections varied. Treat- ment regimens included immunosuppressive drugs and antibiotics. Rhinocerebral mucormycosis was the most common form observed. The predominant secondary infections involved the urinary tract, respiratory system, bloodstream (bacteremia), and soft tissues, with resistant strains of Acinetobacter baumannii, Escherichia coli, and Klebsiella pneumoniae being the most frequently identified microorganisms. Notably, cases of bacteremia and pneumonia exhibited a higher mortality rate. Ultimately, 55.6% of patients were discharged, while 44.4% succumbed to their infections.

Patients recovering from COVID-19 with mucormycosis are significantly susceptible to secondary bacterial infections, particularly those with diabetes mellitus or those undergoing immunosuppressive therapy. Such infections com- pound the morbidity and mortality risks in this vulnerable patient cohort.

During the coronavirus pandemic, the overuse of antibiotics to reduce coinfections and mor- tality may be contributing to the rise of antimicrobial resistance. In this study, we aim to investigate the antibiotic resistance changes of Acinetobacter baumannii post-COVID-19 pandemic in Northern Iran.

The current study is a cross-sectional study. Between 2022 and 2023, 2190 clinical samples were collected from patients with healthcare-associated infections (HAIs) at four hospitals in Sari, which served as corona centers after the COVID-19 pandemic. Antimicrobial sensitivity was determined using standard broth macro-dilution, and resistance genes were detected using multiplex PCR.

Based on the results co-amoxiclav had a resistance rate of 100%, while piperacillin/tazobactam showed the least resistance rate of 29.82%. In terms of GM MIC values, colistin was the most potent against multi-drug resistant isolates. The frequency of bla OXA-51 , ampC, aphA6, and bla NDM genes were 100%, 99.12%, 90.35%, and 69.30% respectively.

Our study revealed high multi-drug resistance rates. Piperacillin/tazobactam recommended for treating multi- drug resistant Acinetobacter baumannii infections in Northern Iran.

The prevalence of Acinetobacter baumannii as a causative agent of hospital-acquired infections, particularly in burn units and intensive care units, is a major concern due to its innate and acquired resistance to several antibiotics. The presence of beta-lactamase-encoding genes in this bacterium has made it resistant to carbapenems as the last-resort antibiotics for treating infections caused by A. baumannii. This study aims to determine the prevalence of β-lactamase-encoding genes and antibiotic resistance of A. baumannii isolates from burn patients in northern Iran.

In this descriptive cross-sectional study, A. baumannii isolates were obtained from clinical samples of patients in Zare Burn Hospital in Sari City, from 2013 to 2015. The isolates’ antibiotic sensitivity was determined using the disk diffusion method. To investigate the prevalence of β-lactamase genes (blaVIM, blaIMP, and INT), the PCR test was conducted.

Of 150 patients, 54.7% were men and 45.3% were women. The highest resistance rateswere against ceftazidime, cefepime, meropenem, imipenem, ciprofloxacin, amikacin, gentamicin, and colistin in order. It was observed that 31% of the isolates produced metallo-β-lactamase enzyme. The genes blaVIM, blaIMP, and INT were detected in 35%, 45%, and 60% of the isolates, respectively.

A. baumannii isolates have significant resistance to cephalosporins and carbapenems. It is recommended to avoid the irrational prescription of cephalosporins and carbapenems for infections
caused by A. baumannii.

Extended Spectrum Beta Lactamase (ESBL)-Producing Acinetobacter baumannii has threatened patients’ optimal healthcare in various tertiary care hospitals globally. The paucity of information regarding this life-threatening organism in Nigeria necessitated this research. Hence, this study aimed to molecularly characterize ESBL-producing A. baumannii among debilitated patients in a tertiary care hospital in Ebonyi State, Nigeria. Debilitated patients admitted in the intensive care unit (ICU), medical, surgical, and orthopedic wards were sampled, and 385 clinical samples were obtained from them over a six-month study period. Standard microbiological methods were used to identify A. baumannii isolates, while 16S rRNA PCR was used to confirm the isolates molecularly. The Kirby-Bauer disc diffusion techniques were used to ascertain the antibiotic sensitivity profiles of A. baumannii isolates. The double disc synergy test (DDST) method was employed to determine ESBLs production among the isolates, while to determine A. baumannii isolates harboring blaTEM, blaSHV, and blaOXA genes, PCR techniques were used. A total of 23 (6%) A. baumannii isolates were recovered from 385 clinical samples. The isolated A. baumannii exhibited multidrug resistance (MDR) traits, while 43.5% of the isolates were ESBL-producing A. baumannii. Also, 9 (90%) and 3 (30%) of the isolated A. baumannii harbored blaTEM and blaOXA genes, respectively, while no isolate harbored the blaSHV gene. The isolated A. baumannii were observed to harbor ESBL genes. Importantly, this is the first report of ESBL-producing A. baumannii in Ebonyi State, Nigeria.

Acinetobacter baumannii (A. baumannii) is one of the most common bacteria in nosocomial infections. Inappropriate usage of antibiotics has led to expanding emergence resistance to A. baumannii as a multidrug-resistant (MDR) strain. Empirical antibiotic therapy is necessary to evaluate the resistant gene pattern of MDR A. baumannii. For this purpose, the present study evaluated the resistance genes pattern of MDR A. baumannii collected from hospitalized patients using a genotypic diagnostic technique. To find evidence related to the study objectives, databases were searched such as Google Scholar, Web of Science, Science Direct, PubMed, and Scopus from 2000 to 2022, with specified keywords in the title and text of the articles. Articles were included based on inclusion and exclusion criteria. The mentioned database displayed 284 articles. After screening, 65 eligible articles were included. The results showed that various b-lactamases genes, aminoglycoside-modifying enzymes (AMEs) genes, and pump-expressing genes are resistance gene patterns in MDR A. baumannii isolates. MDR A. baumannii has significantly become resistant to b-lactams, carbapenems, and aminoglycosides.

Secondary bacterial and fungal infections are a significant concern in COVID-19 patients, particularly those critically ill and requiring intensive care. This retrospective study investigated the prevalence and spectrum of secondary infections among COVID-19 patients admitted to the intensive care unit (ICU) at a tertiary care hospital in Navi Mumbai. Additionally, we explored the association between secondary infections and patient comorbidities.

We performed a single-center, retrospective cohort study of 3234 COVID-19 patients admitted to a tertiary care hospital in Navi Mumbai, India, between August 2020 and August 2021. Microbiological data from various clinical specimens, including blood, sputum, bronchoalveolar lavage (BAL) fluid, urine, and tissue cultures, were retrospectively analyzed. Patient demographics and comorbidities were extracted from medical records. We employed descriptive statistics and Pearson's Chi-square test for data analysis to identify associations between secondary infections and patient characteristics.

Among the 3234 COVID-19 patients, 195 (6.02%) presented with clinical features suggestive of secondary infections. Microbiological analysis confirmed secondary infections in 98 patients (3.03%), with a culture positivity rate of 50.3%. Among bacterial isolates, Klebsiella pneumoniae was the most prevalent (43.28%), followed by Acinetobacter baumannii (25.37%). Aspergillus spp. emerged as the dominant fungal pathogen. Notably, Escherichia coli isolation was significantly associated with various specimen types (P < 0.001). However, no significant correlation was found between secondary infection rates and patient comorbidities.

Gram-negative bacteria, specifically K. pneumoniae and A. baumannii, were the primary pathogens responsible for secondary infections in our cohort of critically ill COVID-19 patients admitted to the ICU. These findings underscore the importance of ongoing surveillance and monitoring of secondary infection trends, including fungal pathogens, to inform and optimize management strategies in this high-risk population.

A. baumannii is a gram-negative pathogen that has become one of the most important challenges in the world due to its high antibiotic resistance, and today many efforts are being made to treat infections caused by it. In recent years, there have been many concerns about increasing resistance to the beta-lactam antibiotic, carbapenem. Because resistance to these antibiotics greatly narrows the treatment options for the infections. The main source of carbapenem resistance in A. baumannii is the production of class D carbapenemase enzymes.

In this study, 27 plant ligands that have been shown to have antibacterial effects against A. baumannii and other resistant bacteria were selected. The chemical structure of the ligands and the three-dimensional structure of carbapenemase OXA-58 were extracted. The requirements of oral consumption of ligands were examined and ligand and OXA-58 docking were performed. 9 ligands including baicalein, berberine, curcumin, ellagic acid, epicatechin, honokiol, magnolol, norwogonin, and thymol, which met the requirements of Rule 5 and had better binding affinity than 6-alpha-hydroxymethyl penicillanate were selected. Redocking with a focus on the active position was performed by AutoDock software.

The amino acids involved in the hydrogen bonding of an antibiotic-representative ligand to the receptor were identified. Ligands that bind to at least one of these amino acids at the binding site by hydrogen bond were selected. Pharmacological and toxicity studies were performed and finally, the epicatechin ligand was introduced as the best ligand.

Plant ligands can be further investigated as promising antibiotic adjuvants and used in the future.

Acinetobacter baumannii strains harboring Meallobetalactamases (MBL) pose a significant threat in the context of nosocomial infections. The present investigation was undertaken with the objective of devising a Multiplex PCR methodology for the concurrent detection of MBL genes within A. baumannii strains prevalent in Tehran City, Iran.

Between October 2020 and February 2021, 100 strains of A. baumannii were procured from burn specimens of hospitalized patients at Motahhari Hospital in Tehran. The identification of A. baumannii strains involved conventional biochemical techniques, coupled with confirmation of the presence of the bla OXA-51 gene. Antibiotic susceptibility was assessed using the Kirby–Bauer disc diffusion test. MBL-producing strains were characterized through a phenotypic approach employing the combined disk test, alongside Multiplex PCR for the simultaneous identification of bla VIM, bla IMP, bla GIM, and bla NDM genes. Statistical analyses were conducted using the chi-square test, with SPSS version 20.0 employed for data processing.

Among 100 strains examined, 96.1% exhibited positivity for MBL, as determined by the combined disk test. The study revealed a predominance of extensively drug-resistant (XDR) strains, with colistin demonstrating the highest level of sensitivity. The genotypic assay unveiled that Multiplex PCR identified bla VIM, bla NDM, and bla IMP in 20 strains, bla VIM and bla NDM in 30 strains, and exclusively the bla NDM gene in 45 strains. Notably, the Multiplex PCR technique exhibited the capacity to concurrently detect MBL genes (bla VIM, bla IMP, bla GIM, bla NDM) in 2 strains.

The current investigation underscores prevalence of the bla NDM gene within clinical strains of A. baumannii. Furthermore, Multiplex PCR emerges as a robust and highly sensitive technique for rapid discernment of the MBL genes within in A. baumannii strains.

 The emergence of antimicrobial-resistant pathogens in intensive care units (ICU) makes treatment of these infections very difficult.

 This study aimed to survey the resistance phenotype, risk factors, and possible treatment options for hospital-acquired infections (HAI) at ICUs in a referral university hospital.

 Samples were prepared from ICU patients with HAIs. Pathogens were isolated, and the resistance phenotype, prescribed antibiotics, mortality rate, associated risk factors, and clonal relationship of the isolates were assessed.

 From 100 patients admitted to ICUs, 76 (76%) showed clinical symptoms of HAIs. The most common sources of infection were lung secretions (51.8%). The isolated bacteria were Gram-negative (77, 90.6%) and Gram-positive (9.4%). The most common isolated microorganism was the Acinetobacter baumannii complex (63.5%). The most effective antimicrobials were colistin (96.1%) and linezolid (100%) for Gram-negative and Gram-positive isolates, respectively. An extensively drug-resistant (XDR) phenotype was documented in all isolates of A. baumannii, Pseudomonas aeruginosa, and Serratia marcescens. The XDR phenotype was a significant risk factor only for mortality. A. baumannii had the highest mortality rate (66.6%) among all the isolates. While A. baumannii strains had limited diversity, the other species were highly divergent.

 The results revealed a high mortality rate for Gram-negative isolates, especially in adenosine triphosphate-binding cassette (ABC). The high genetic similarities of ABC strains might be an indication of neglecting infection control prevention. The use of cotrimoxazole and colistin instead of carbapenems can be promising for mortality reduction in the studied ICUs.

 Acinetobacter baumannii is an important pathogen due to its ability to cause a wide range of infections, particularly in healthcare settings, and its propensity to develop multidrug resistance, posing significant challenges for treatment and infection control measures. Flavonoid and Oxadiazoles compounds play a significant role in human health due to their biological activities.

 The purpose of this study is to investigate the anti- A. baumannii effects of flavonoid compounds and oxadiazole derivatives.

 Structures with oxadiazole central core were re-synthesized. Agar well diffusion, minimum inhibitory concentration, and minimum bactericidal concentration methods were performed In vitro. The structure of the oxadiazole derivatives and 10 compounds of flavonoids as ligands were optimized by the mm2 method with Chem3D v20.1.1.125 software. The ligands were evaluated as an inhibitor against the active site of the OXA-23 by AutodackVina software. The output results were analyzed and evaluated by Discovery Studio v16.1.0 software.

 The results demonstrated that derivatives B (oxadiazole with dibromophenyl) and D (oxadiazole with dimethoxyphenyl) exhibited stronger anti- A. baumannii effects compared to other compounds and the control sample. Furthermore, the In silico results revealed the inhibitory effects of derivatives D from oxadiazole and eriocitrin and narirutin from flavonoid compounds against OXA-23 by forming hydrogen bonds for inhibition.

 The dimethoxyphenyl structure with the oxadiazole core and eriocitrin and narirutin from flavonoid compounds can be used as an anti- A. baumannii agent in the development of therapeutic drugs.

Increased multidrug-resistant (MDR) Acinetobacter baumannii infections pose a significant challenge in hospital settings. Enhanced resistance to antibiotics like fluoroquinolones and β-lactams necessitates adopting alternative treatment strategies such as metal oxide nanoparticles. This study investigated the synergistic effect of zinc oxide nanoparticles (ZnO-NPs) on ciprofloxacin and ceftazidime activity against MDR A. baumannii.

We examined 30 MDR A. baumannii isolates from intensive care unit (ICU) patients in Iran. ZnO-NPs were synthesized via the solvothermal method and characterized using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) to ascertain their crystalline structure and morphology. Antibacterial activity was evaluated by determining minimum inhibitory concentrations (MICs) and inhibition zones through broth microdilution and disk diffusion methods, using concentrations of ciprofloxacin and ceftazidime in combination with ZnO-NPs.

ZnO-NPs combined with ciprofloxacin 8 μg/mL and ceftazidime 32 μg/mL exhibited inhibition growth percentage (GI%) increases of 44.9% and 31.65%. 

The enhanced in vitro antibacterial effects of combined ZnO-NPs and antibiotics against MDR A. baumannii indicate a synergy. Considering the limited number of isolates, comprehensive research incorporating in vivo models and clinical trials is warranted to evaluate the practicality of this approach in overcoming antibiotic resistance.

Despite progress in diagnosing and managing ventilator-associated pneumonia (VAP), ongo- ing monitoring of ventilator-associated events (VAE) is crucial due to VAP's persistent prominence as the primary cause of Hospital-Acquired Infection (HAI) among Intensive Care unit patients. This study was done to illuminate the prevalence of VAE and antibiogram of bacterial isolates of VAP in a tertiary care hospital of Uttarakhand.

This cross-sectional study focused on ICU patients. Adult patients ventilated for > 2 days were monitored daily, with VAE data analyzed using Center of Disease Control & Prevention (CDC) criteria. Specimens were sent to the Microbiology Department and cultured on Blood agar and MacConkey agar. Identification and antimicrobial profiles of isolates were determined using Vitek-2 Compact.

1220 ventilated individuals were assessed in total. VAE was diagnosed in 6.4% (78/1220) of the patients, the same later developed ventilator associated condition (VAC), 74 developed the infection-related VAC (IVAC), and 60 developed the possible/probable VAP (PVAP) among the 78 VAE cases. Klebsiella pneumoniae (35%), Acinetobacter baumannii (33%), and Pseudomonas aeruginosa (16%) were the most common isolated organisms. Colistin (57%) was the most effective against Klebsiella pneumoniae, followed by amikacin (28.5%) and trimethoprim+sulfamethoxazole (24%). Pseudomonas aeruginosa was most susceptible to imipenem (70%), meropenem, cefoperazone+sulbactam, and colistin (60%). Acineto- bacter baumannii was most susceptible to colistin (85%), tigecycline (65%), and trimethoprim+sulfamethoxazole (25%).

The most common cause of HAI is VAP. The purpose of this study is to determine the importance of starting suitable antibiotics early for prognosis and the difficulty of diagnosing VAP.

 Detecting the source of a potential outbreak of multidrug resistant (MDR) Acinetobacter baumannii is necessary to be investigated. This study aimed to detect the possibility of A. baumannii outbreak in a hospital setting using a combination of random amplified polymorphism DNA- polymerase chain reaction (RAPD-PCR), antibiograms, and the presence of oxacillinase genes.

 The antibiogram of 31 clinical isolates and six environmental isolates of A. baumannii were determined by Vitek® 2 Compact. Oxacillinase genes (OXA-23, -24, -51, and -58) were detected by PCR, and RAPD-PCR was conducted using DAF-4 and ERIC-2 primers. The Similarity Index and dendrogram were generated using GelJ v2.3 software.

 The antibiograms showed that all MDR A. baumannii isolates has very limited susceptibility to cephalosporins, but mostly susceptible to tigecycline. All isolates were positive for blaOXA-51-like gene, thirty-two of 37 total isolates (86.5%) were positive for blaOXA-23-like gene, and none were positive for blaOXA-24-like and blaOXA-58-like genes. RAPD-PCR showed that the DAF-4 primer on average had more band visualization and lower Similarity Index’s variation compared to the ERIC-2. The discriminatory power of DAF-4 was 0.906. There was a significant correlation between the DAF-4 dendrogram pattern with the antibiogram (r=0.494, p<0.001) and the presence of blaOXA-23-like gene (r=0.634, p<0.001) from all ICU A isolates. Six out of fourteen ICU A isolates belonged to the same cluster with >95% Similarity Index, while one clinical isolate having an identical dendrogram and antibiogram pattern with an environmental isolate within this cluster.

 There is a high probability of MDR A. baumannii outbreak within ICU A detected by multiple analysis of RAPD-PCR, antibiogram and the blaOXA-23-like gene profiles. This combinatorial approach is conceivable to mitigate possible outbreak situations of A. baumannii in the local hospital without sophisticated microbiology laboratory.

Acinetobacter baumannii, an opportunistic pathogen, is related to hospital-acquired infections and increased mortality. This study aimed to develop the loop-mediated isothermal amplification (LAMP) test for the fast-de- tecting of A. baumannii isolates as well as determining genetic relatedness for these isolates via the REP-PCR technique.

LAMP primers and multiplex PCR primers were designed for recognizing A. baumannii isolates harboring the bla SHV-1 , bla PER-1 , bla , AMPC, qnr, and aac (6)-1 genes, were collected (October 2020 to February 2021) from Shahid Motahari Hospital, Tehran, Iran. Combination disc test (CDT) results were used to assess the phenotypic iden- tification of isolates from ESBL producers. The sensitivity of the LAMP method was evaluated using a range of serial dilu- tions of genomic DNA. Results were compared between the LAMP technique, and multiplex PCR. The genetic diversity of clinical isolates was determined by REP-PCR.

Among one hundred A. baumannii samples and based on the combined disc test, 56% of isolates were ESBL pro- ducers. The sensitivity of the LAMP technique for the identification of A. baumannii was 4.06 ng/μl whilst the multiplex PCR was (16.2 ng/μl). Regarding multiplex PCR, (68%) of the isolates were bla SHV-1 positive, (40%) bla , (85%) aac (6́)-1, AMPC (67%), bla TEM-1 (63%), and (15%) qnr respectively. While in LAMP, (69%) of isolates were bla positive, (86%) aac (6')-1, and (20%) qnr. The results of AMPC, bla TEM-1 , and bla PER-1 genes showed 100% compatibility between multiplex PCR and LAMP assays. The results of REP-PCR indicated there were 17 clones, clone A at 14% was the most prevalent of the isolates.

Wherever equipment and financial constraints are crucial, the LAMP test offers a better and more potent detec- tion rate for the identification of A. baumannii isolates than multiplex PCR. Furthermore, the genetic diversity of A. bauman- nii in these clinical isolates showed frequent commonality of genotypes.

Antibacterial peptides have a broad antibacterial spectrum and are not affected by classical resistance mechanisms; therefore, they can be used in combination with classic antibiotics to treat multidrug-resistant Acinetobacter baumannii infections, making them an alternative for the development of new therapeutic strategies.

This study aimed to assess the effectiveness of combining amphiphilic peptides, specifically C12-prp and mastoparan, with antibiotics in combating A. baumannii clinical isolates.

We investigated combinations that inhibited the growth of A. baumannii clinical isolates, consisting of 24 extensively drug-resistant (XDR) and 11 pan-drug-resistant (PDR) strains collected between January 2004 and December 2014 at Chosun University Hospital using a multiple combination bactericidal test (MCBT). A time-kill study was used to confirm the bactericidal activity and synergism of the four combinations selected via MCBT.

Four combinations (C12-prp-colistin, C12-prp-rifampicin, mastoparan-colistin, and mastoparan-rifampicin) showed 100% (24/24) synergy with XDR A. baumannii strains. However, in the case of the PDR strains, only two combinations, C12-prp-colistin and mastoparan-colistin, showed a 9.1% (1/11) synergy. Moreover, the mastoparan-colistin and mastoparan-rifampicin combinations showed 100% (24/24) bactericidal activity against the XDR A. baumannii strains, whereas the C12-prp-colistin and C12-prp-rifampicin combinations showed 91.7% (22/24) bactericidal activity. None of the combinations showed bactericidal activity against PDR strains.

Our study highlighted the substantial synergistic antibacterial efficacy of C12-prp and mastoparan peptides when combined with colistin or rifampicin. Furthermore, this approach could be a promising alternative for developing new treatment strategies for XDR A. baumannii infections.

 Most Acinetobacter baumannii species have become resistant to all common antibiotics. Many antimicrobial peptides (AMPs) have been identified with efficient functions in infection management. E50-52 (UniProtKB: P85148) and Ib-AMP4 (UniProtKB: O24006) AMPs have shown marked antibacterial functions.

 This investigation was designed to produce E50-52 and Ib-AMP4 AMPs through recombinant protein production. Subsequently, the synergistic antimicrobial functions of these two peptides were assessed under in vitro and in vivo circumstances on multidrug-resistant A. baumannii to investigate the antimicrobial effects of Ib-AMP4 and E50-52 AMPs on drug-resistant Acinetobacter.

 The gene sequence of E50-52 and Ib-AMP4 AMPs were codon optimized and separately inserted into the pET-32α vector. The recombinant structures were expressed in host bacteria. The antibacterial functions of the individual and combined application of the purified refolded E50-52 and Ib-AMP4 AMPs against multidrug-resistant A. baumannii were evaluated through the time-kill, minimum inhibitory concentration (MIC), growth kinetic assays, and in vivo (mouse body) systemic infection.

 The minimum concentrations of the produced refolded E50-52 and Ib-AMP4 AMPs against A. baumannii were 0.325 and 0.0625 mg/mL, respectively. Moreover, the checkerboard procedure confirmed the synergic effects of the produced AMPs. The use of E50-52 and Ib-AMP4 AMPs in combination resulted in an over five times reduction in log10 CFU/mL of alive cells during the first 240-min exposure. The antibacterial efficiency of the produced AMPs was confirmed by growth kinetic assays, scanning electron microscopy (SEM) results, and in vivo evaluation tests. The in vivo assay on rats confirmed the significant antibacterial functions of the produced recombinant proteins on A. baumannii systemic infection.

 The results proved the considerable synergistic antibacterial functions of the produced recombinant Ib-AMP4 and E50-52 AMPs to treat A. baumannii systemic infection effectively.