Multi-drug resistant Acinetobacter ventilator-associated pneumonia

Comparison of the effectiveness of savlon antiseptic with povidone-iodine for acinetobacter baumannii infected wounds in white rats (Rattus Norvegicus)

Wound washing with antiseptic liquid is one step in the management of chronic wounds. In infected wounds, washing with antiseptic is expected to reduce bacterial colonies and help eradicate infection. One of the important pathogenic bacteria is Acinetobacter Baumannii. These opportunistic germs can form colonies, especially in patients receiving broad-spectrum antibiotic therapy, treatment in the ICU, and on skin affected by burns. Antiseptic commonly used to wash wound are Savlon and Povidone-iodine 10%. Both antiseptic are broad spectrum antisepctic, kill gram negative and gram positive bacteria. However Savlon could caused skin irritation. Therefore dilution is needed to prevent this effect. This study was intended to determine the difference and comparison of the effectiveness of Savlon and Povidone iodine antiseptic to bacterial growth on wound infected by Acinetobacter Baumannii.  This study is an experimental study with a randomized controlled trial without blinding. The wound research procedure was made on the right and left sides of the rat's back with a size of 1x1 cm each. Wounds that have been contaminated with Acinetobacter Baumannii are left for 4 hours. After 4 hours the wound will be washed and irrigated. The wound that has been made is closed with a transparent dressing.

A rapid evidence assessment exploring whether antimicrobial resistance complicates non-infectious health conditions and healthcare services, 2010-20

Antimicrobial resistance (AMR) is one of the greatest public health threats at this time. While there is a good understanding of the impacts of AMR on infectious diseases, an area of less focus is the effects AMR may be having on non-communicable health conditions (such as cancer) and healthcare services (such as surgery). Therefore, this study aimed to explore what impact AMR is currently having on non-communicable health conditions, or areas of health services, where AMR could be a complicating factor impacting on the ability to treat the condition and/or health outcomes. To do this, a rapid evidence assessment of the literature was conducted, involving a systematic approach to searching and reviewing the evidence. In total, 101 studies were reviewed covering surgery, organ transplants, cancer, ICUs, diabetes, paediatric patients, immunodeficiency conditions, liver and kidney disease, and physical trauma. The results showed limited research in this area and studies often use a selective population, making the results difficult to generalize. However, the evidence showed that for all health conditions and healthcare service areas reviewed, at least one study demonstrated a higher risk of death for patients with resistant infections, compared with no or drug-susceptible infections. Poor health outcomes were also associated with resistant infections in some instances, such as severe sepsis and failure of treatments, as well as a greater need for invasive medical support. While there are gaps in the evidence base requiring further research, efforts are also needed within policy and practice to better understand and overcome these challenges.

Antimicrobial Activity of Colistin Against Contemporary (2015 – 2017) P. aeruginosa and A. baumannii Isolates From a Chinese Surveillance Program

Objective

To investigate the incidence and susceptibilities of non-fermenting bacteria isolates from Chinese respiratory (RTI), intra-abdominal (IAI) and urinary tract (UTI) infections to antimicrobial agents between 2015 and 2017.

Methods

In total, 3,246 non-fermentative bacteria were collected from 21 hospitals and 9 hospital departments across 7 regions of China. A central testing laboratory was employed to determine antimicrobial susceptibilities using appropriate standards of interpretation.

Results

The majority of the isolates were Acinetobacter baumannii (n = 1,360, 41.9%) and Pseudomonas aeruginosa (n = 1,341, 41.3%). Overall multidrug resistance (MDR) and carbapenem resistance (CR) rates of Acinetobacter baumannii were 80.1 and 78.7% with MDR and CR rates in RTIs, IAIs, and UTIs of 82.0 and 81.0%, 82.6 and 81.0% as well as 53.1 and 46.9%. Overall MDR and CR rates of Pseudomonas aeruginosa isolates were 36.2 and 38.9% with 41.8 and 44.3%, 29.3 and 36.1% as well as 24.2 and 20.2% MDR and CR rates in RTIs, IAIs, and UTIs. Overall susceptibility rates to imipenem, meropenem, amikacin, ciprofloxacin, cefepime and piperacillin-tazobactam were 21.1, 21.3, 33.0, 18.4, 19.2, and 19.6% for Acinetobacter baumannii and 56.5, 58.5, 88.4, 63.1, 63.1, and 55.63% for Pseudomonas aeruginosa isolates, whereas for colistin they were 95.7 and 94.6%, respectively. In all departments and regions of China, susceptibility rates of Pseudomonas aeruginosa and Acinetobacter baumannii isolates to colistin were constantly above 80%.

Conclusion

Due to the high MDR and CR rates for Pseudomonas aeruginosa and Acinetobacter baumannii, isolates obtained from RTIs, IAIs, and UTIs only maintained high susceptibility rates to colistin between 2015 and 2017.

Lung tissue microbial profile in lung cancer is distinct from emphysema

OBJECTIVES

The composition and structure of site-specific microbiota have been investigated as potential biomarkers for a variety of chronic inflammatory diseases and cancers. While many studies have focused on the changes in the airway microbiota using respiratory specimens from patients with various respiratory diseases, more research is needed to explore the microbial profiles within the distal lung parenchyma in smokers with lung cancer and/or emphysema.

MATERIALS AND METHODS

To describe and contrast lung tissue-associated microbial signatures in smokers with lung cancer and/or emphysema, we employed culture-independent pyrosequencing of 16S rRNA gene hypervariable V4 region and compositional analysis in non-malignant lung tissue samples obtained from 40 heavy smokers, including 10 emphysema-only, 11 lung cancer-only, and 19 with both lung cancer and emphysema.

RESULTS AND CONCLUSION

The emphysema-only group presented a lower bacterial community evenness defined by a significantly lower Shannon diversity index compared to the lung cancer patients with or without emphysema (P = 0.006). Furthermore, community compositions of lung cancer patients with or without emphysema were characterized by a significantly lower abundance of Proteobacteria (primary the genera Acinetobacter and Acidovorax) and higher prevalence of Firmicutes (Streptococcus) and Bacteroidetes (Prevotella), compared to emphysema-only patients. In conclusion, the lung microbial composition and communities structures of smokers with lung cancer are distinct from the emphysema-only patients. Although preliminary, our findings suggest that lung microbiome changes could be a biomarker of lung cancer that could eventually be used to help screening for the disease.

Interim Study: Comparison Of Safety And Efficacy of Levofloxacin Plus Colistin Regimen With Levofloxacin Plus High Dose Ampicillin/Sulbactam Infusion In Treatment of Ventilator-Associated Pneumonia Due To Multi Drug Resistant Acinetobacter

Due to the emerging antibiotic resistance of Acinetobacter, which is the leading cause of ventilator-associated pneumonia (VAP) in critically ill patients, there is an urgent need for studies comparing various antibiotic regimens for its treatment. In this single blinded randomized clinical trial, adult patients with VAP due to multi drug resistant Acinetobacter (MDRA), were randomly assigned to receive 9×10⁹ unit loading dose of colistin followed by 4.5×10⁹ unit intravenously twice daily plus 750 mg intravenous levofloxacin daily or continuous infusion of ampicillin/sulbactam, 24g daily plus 750mg IV levofloxacin daily. Dose and dosing interval were adjusted according to serum creatinine levels during the study. Clinical and microbiological cure, inflammatory biomarkers, and possible adverse effects were recorded in participants. Twenty-nine patients were recruited (14 in colistin and 15 in ampicillin/sulbactam groups). Three patients were excluded in each group. Clinical response occurred in 3 (27%) and 10 (83%) in colistin and ampicillin-sulbactam arms, respectively (P = 0.007). Nephrotoxicity happened in 6 (54%) and 1 (8%) of cases in colistin and ampicillin-sulbactam groups, (P = 0.016). 14-day and 28-day survival rate were significantly higher in ampicillin-sulbactam group compared to colistin arm with P values of 0.002 and 0.049, respectively. This study revealed that levofloxacin plus high dose ampicillin/sulbactam as continuous infusion is more effective than levofloxacin plus colistin in patients with MDR Acinetobacter VAP with significantly lower risk of nephrotoxicity.

Tn2008-driven carbapenem resistance in Acinetobacter baumannii isolates from a period of increased incidence of infections in a Southwest Virginia hospital (USA)

OBJECTIVES

The objectives of this study were (i) to determine the genetic basis for carbapenem resistance in multidrug-resistant (MDR) Acinetobacter baumannii strains isolated from patients affected by a sudden increase in the incidence of infections by such organisms in a tertiary care hospital in Virginia, USA, in 2009-2010 and (ii) to examine whether such strains are commonly encountered in the hospital setting.

METHODS

The whole genomes of one outbreak strain as well as one carbapenem-resistant and one carbapenem-sensitive strain from sporadic infections in 2010-2012 were sequenced and analysed. Then, 5 outbreak isolates and 57 sporadic isolates (of which 39 were carbapenem-resistant) were screened by PCR for relevant DNA elements identified in the genomics investigation.

RESULTS

All three strains for which whole-genome sequences were obtained carried resistance genes linked to MDR phenotypes and a ca. 111-kbp plasmid (pCMCVTAb1) without drug resistance genes. Of these, the two carbapenem-resistant strains possessed a ca. 74-kbp plasmid (pCMCVTAb2) carrying a Tn2008 transposon that provides high-level carbapenem resistance. PCR analysis showed that all of the outbreak isolates carried both plasmids and Tn2008, and of the sporadic isolates 88% carried pCMCVTAb1, 25% contained pCMCVTAb2 and 50% of the latter group carried Tn2008.

CONCLUSIONS

Carbapenem resistance in outbreak strains and 12% of sporadic isolates was due to the pCMCVTAb2-borne Tn2008. This is the first report of a Tn2008-driven outbreak of carbapenem-resistant A. baumannii infections in the Commonwealth of Virginia, which followed similar cases in Pennsylvania and Ohio.

Multidrug and co-resistance patterns of non-fermenting Gram-negative bacilli involved in ventilator-associated pneumonia carrying class 1 integron in the North of Iran

INTRODUCTION

Ventilator-associated pneumonia (VAP) due to non-fermenting Gram-negative bacilli (NFGNB), especially Pseudomonas aeruginosa and Acinetobacter spp., is one of the main hospital-acquired infections leading to mortality and morbidity, especially in intensive care units (ICUs). This study seeks to determine the multidrug and co-resistance (MDR) patterns of NFGNB that are agents of VAP, and assess the presence of class 1 integron in these bacteria.

METHODS

This cross-sectional study involved VAP patients admitted in the ICUs of 18 hospitals in the Mazandaran province, located in the North of Iran. The antibiotic susceptibility pattern was determined by the minimum inhibitory concentration (MIC) test by using broth microdilution method. Presence of class 1 integron was evaluated by the polymerase chain reaction (PCR) assay.

RESULTS

Out of a total of 83 patients who were microbiologically diagnosed as VAP, 52 non-duplicated NFGNBs (24 P. aeruginosa and 28 A. baumannii) were causative of VAP, out of which MDR NFGNBs were responsible for 48 (57.83%) cases. The frequencies of MDR NFGNBs were as follows: 27 (56.25%) A. baumannii and 21 (43.75%) P. aeruginosa. P. aeruginosa isolates were resistant to all aminoglycoside antibiotics (50%), ciprofloxacin (45.8%), ceftazidime (70.8%), cefepime (87.5%), colistin (62.5%), and imipenem (29.2%). A. baumannii isolates were resistant to aminoglycosides (53.6%), ciprofloxacin (85.7%), ceftazidime (92. 9%), cefepime (92.9%), colistin (35.7%), and imipenem (57.1%). Twelve isolates were resistant to all 10 tested antibiotics. The number of rates of class 1 integron, positive for MDR P. aeruginosa and MDR A. baumannii, were 20 (95.23%) and 21 (77.78%), respectively.

CONCLUSION

The high prevalence of multidrug resistance and incidence of class 1 integron is a therapeutic concern. Employing antibiotic stewardship in hospitals could prevent the dissemination of MDR bacteria.

Management of ventilator associated pneumonia with a new antibiotic adjuvant entity (ceftriaxone+sulbactam+disodium edetate) - A novel approach to spare carbapenems

BACKGROUND

Ventilator associated pneumonia (VAP) is one of the most serious nosocomial infections in Intensive Care Unit (ICU). The aim of this study was to evaluate a new approach to spare the carbapenems for the management of patients diagnosed with VAP due to Acinetobacter baumannii (A. baumannii).

METHOD

This retrospective study was conducted on VAP patients presenting for treatment at tertiary care centre between May 2014 and March 2016. The case sheets of patients who have been treated for VAP with meropenem, antibiotic adjuvant entity (AAE) and colistin were analysed.

RESULTS

Out of 113 patients analysed, 24 (21.3%) patients were having VAP due to MDR A. baumannii. Microbial sensitivity has shown that 87.5% of patients were sensitive to AAE and colistin whereas all of them were resistant to meropenem, imipenem and gentamycin. The mean treatment durations were 12.4±2.1, 13.2±2.4 and 14.3±2.1days for AAE, meropenem+colistin and AAE+colistin treatment groups. In AAE susceptible patients, the mean treatment duration and cost could be reduced by 23-24% and 43-53% if AAE is used empirically. In AAE-resistant patients, the mean treatment duration and cost could be reduced by 21% and 26% if AAE+colistin regime is used empirically instead of meropenem followed by AAE+colistin.

CONCLUSIONS

Clinical assessment with microbial eradication and pharmaco-economic evaluation clearly shows benefits in using AAE empirically in the management of A. baumannii infected VAP cases.

Phenotypic and molecular characterization of clinical isolates of Acinetobacter baumannii isolated from Delhi, India

Background

Acinetobacter has gained importance as a multi-drug resistant and hence a difficult to treat pathogen. This study was done to characterize our isolates with respect to drug resistance and presence of beta-lactamases which is a major mechanism of resistance and to type using RAPD and MLST so that comparison of our clones can be made with the existing international clones.

Methods

100 isolates recovered from clinical samples from two hospitals in Delhi were tested for their susceptibility against major groups of antimicrobials. The resistant isolates were screened and confirmed phenotypically for presence of ESBL, MBL and AmpC and MBLs also by PCR. The isolates were typed by RAPD and MLST.

Results

Out of the 100 isolates, 91, 78 and 2 % were MDR, XDR and PDR respectively. 97, 100 and 85 were screen positive for ESBL, AmpC and MBL respectively. Of these, 38.1 % were confirmed phenotypically to produce ESBL, 99 % produced AmpC and 29.4 % produced MBL comprising of GIM, VIM, SIM and IMP. MLST showed known STs 110, 188, 146, 69, 103, 108 and 194. Eight new STs were encountered. The RAPD showed a high degree of genetic variability among the isolates.

Conclusion

Majority of our isolates were MDR, producing one or more types of beta-lactamases. We encountered drug resistant international clones by MLST which are found in other continents there by confirming their spread to Indian sub continent. No data on ST types of other Indian isolates is available in the MLST database and hence comparison is not possible.

Antibiotic Resistance Profile and Distribution of Oxacillinase Genes Among Clinical Isolates of Acinetobacter baumannii in Shiraz Teaching Hospitals, 2012 - 2013

BACKGROUND

The emergence of multidrug-resistant Acinetobacter baumannii complicates the therapy of the related infections. Hospital isolates of A. baumannii are usually multidrug-resistant. The problem is compounded by increasing resistance to broad-spectrum antibiotics including carbapenems.

OBJECTIVES

The aim of this study was to determine antimicrobial susceptibility patterns and distribution of bla OXA -type carbapenemases genes among A. baumannii isolates from hospitalized patients in Shiraz, Southwest Iran.

MATERIALS AND METHODS

Two hundred A. baumannii isolates were recovered from different clinical specimens in four Shiraz teaching hospitals. Isolates were detected as A. baumannii by Microgen kit and PCR with specific primers of bla OXA-51-like gene. Antimicrobial susceptibility testing was determined by disk diffusion method for all the isolates. Multiplex PCR assays were performed for detection of bla OXA-23-like , bla OXA-24-like and bla OXA-58-like genes.

RESULTS

All the isolates were susceptible to colistin and polymyxin B. Moreover, all of them were resistant to piperacillin, piperacillin-tazobactam, ampicillin, ceftazidime, cefoxitin and aztreonam. Eighty (40%) isolates had positive results for bla OXA-23-like , 14 (7%) for bla OXA-24-like and 1 (0.5%) isolate for bla OXA-58-like . The co-existence of studied genes was detected for bla OXA-23-like plus bla OXA-24-like in nine (4.5%) isolates.

CONCLUSIONS

The prevalence of carbapenem resistant A. baumannii isolates in Shiraz hospitals is high. The bla OXA-23-like gene was the most frequent carbapenemase identified among resistant A. baumannii isolated in Shiraz hospitals. The increasing incidence of A. baumannii is a serious concern, therefore control of this pathogen and taking preventive measures are emphasized.

Comparative Evaluation of Four Phenotypic Tests for Detection of Metallo-β-Lactamase and Carbapenemase Production in Acinetobacter baumannii

INTRODUCTION

Acinetobacter baumannii is an emerging multi-drug resistant opportunistic pathogen that causes a variety of nosocomial infections. In recent years, carbapenem resistance in A.baumannii has increased due to Ambler class B Metallo β-lactamases or class D OXA Carbapenemases.

OBJECTIVE

The present study was undertaken to detect and compare the various phenotypic methods for MBL production in nosocomial A.baumannii isolates.

MATERIALS AND METHODS

One hundred sixty eight A.baumannii isolates were subjected to disc diffusion assay. Imipenem resistant isolates were subjected to 4 different phenotypic tests. MBL screening was done by Imipenem-EDTA double disc synergy test, Imipenem-EDTA combined disc test, Modified Hodge test and MBL E-test.

RESULTS

Out of 168 A.baumannii isolates, 85 (50.59%) were imipenem resistant. Among these 85 isolates, 57 (67.05%) were MBL positive by DDST, 69 (81.18%) by CDT, 85 (100%) by MHT and all these 85 isolates were confirmed to be MBL positive by MBL E-test method.

CONCLUSION

Combined disc test, Modified Hodge test & E-test are equally effective to detect MBL production. However, considering the cost constraints of E-test, simple MHT and CDT can be used. They are easy, economical and can be incorporated into routine testing in laboratories to monitor the emergence of MBLs in MDR A.baumannii.

Multidrug resistant acinetobacter infection and their antimicrobial susceptibility pattern in a nigerian tertiary hospital ICU

BACKGROUND

Acinetobacter baumannii, a non-glucose fermenting Gram negative bacillus, has emerged in the last three decades as a major etiological agent of hospital-associated infections giving rise to significant morbidity and mortality particularly in immunocompromised patients. Multidrug resistant A. baumannii (MDR-AB) is fast becoming a global threat, having developed resistance to major classes of antibiotics and carbapenem-resistant isolates have increasingly been reported worldwide as a cause of nosocomial outbreaks. Despite intensive efforts, nosocomial acquisition of MDR-AB is still a problem due to the organism's great ability to colonize human and environmental reservoirs.

OBJECTIVES

This study was aimed to determine the prevalence of (MDR) AB and their antibiotic susceptibility pattern.

METHODOLOGY

A total of 400 specimens which include tracheal aspirates, catheter specimens of urine, wound biopsies and blood culture collected from 100 patients admitted at the Intensive Care Unit of our hospital over a period of nine months were processed following standard microbiologic procedure.

RESULTS

A total of 155 non-lactose fermenters were isolated out of which 14 (9.0%) were Acinetobacter spp. Eleven (79.0%) out of the 14 Acinetobacter spp were A. Baumanii, while 2 (14.0%) were A. lwoffi and 1(7.0%) A.calcoaceticus. All the isolates were resistant to Amoxicillin-clavulanate, Ceftriaxone, Ciprofloxacin, Ofloxacin, gentamicin and Ampicillin-sulbactam; while susceptibility to Meropenem, Amikacin and Levofloxacin were 64.3%, 50.0% and 35.7% respectively.

CONCLUSION

The high rate of antibiotic resistance shown by Acintobacter isolates in this study demonstrates the need for antibiotic stewardship protocols to be set up in health facilities to prevent outbreaks of multi-resistant bacterial infections.

Genotyping of carbapenem resistant Acinetobacter baumannii isolated from tracheal tube discharge of hospitalized patients in intensive care units, Ahvaz, Iran

BACKGROUND AND OBJECTIVES

Carbapenem resistant A. baumannii is an emerging cause of nosocomial infections. The aims of this study were identification of the most prevalent of carbapenem resistant genes, molecular typing and antimicrobial evaluation of A.baumannii in intensive care units.

MATERIALS AND METHODS

Two hundred and six A. baumannii were isolated from tracheal tube discharge of hospitalized patients at different intensive care units in Ahvaz, Iran. Antimicrobial susceptibility test was done on all isolates. Multiplex and singleplex PCR were performed for detection of bla OXA-23-like, bla OXA-24-like, bla OXA-51-like, bla OXA-58-like, bla VIM, bla IMP, bla SPM and bla NDM genes. Genetic relationship of all isolates was determined by REP-PCR method.

RESULTS

Out of 206 examined isolates, 198 (96.1%) isolates were resistant to imipenem and meropenem. However 3.9% isolates were sensitive to these antibiotics. The bla OXA-23-like and bla OXA-24-like genes were detected in 85% and 8.7% of strains, respectively. No bla OXA-58- like, bla IMP, bla VIM, bla SPM and bla NDM were detected. REP-PCR results showed that isolates were belonged to five genotypes: Genotype A was the most prevalent (P- value < 0.001): it was observed in 75 of 206 strains (36.4%). Genotype B, and C were found in 28.6% and 27.7%, respectively. The rate of other genotypes was as follows: D (2.4%), E (1%).

CONCLUSION

Based on the obtained results, the rate of carbapenem resistance was high among of A. baumannii which was isolated from intensive care units patients and oxacillinase genes were the most prevalent carbapenem resistant genes. These results revealed that three clones, A, B and C of A.baumannii are common in our hospitals.