Search

This article evaluates the use of an artificial intelligence tool called ChatGPT in the field of respiratory medicine. ChatGPT is designed to provide human-like responses to a wide range of topics, including medical inquiries. However, there are concerns about its accuracy and reliability in the medical sector, as it has not been extensively trained with biomedical datasets or vetted by medical professionals. The study found that ChatGPT provided correct answers for 63.5% of respiratory medicine questions, with higher accuracy in basic medical knowledge and lower accuracy in treatment and management. It is important to note that ChatGPT should not replace professional medical advice and should be used with caution. The article highlights the limitations of ChatGPT and suggests that it can be used as a supplementary educational tool under expert guidance. Future research should focus on improving the model's accuracy and reliability in specialized domains like respiratory medicine. [Extracted from the article]

Interactions between host and bacterial cells are integral to human physiology. The complexity of host–microbe interactions extends to different cell types, spatial aspects, and phenotypic heterogeneity, requiring high‐resolution approaches to capture their full complexity. The latest breakthroughs in single‐cell RNA sequencing (scRNA‐seq) have opened up a new era of studies in host–pathogen interactions. Here, we first report a high‐throughput cross‐species dual scRNA‐seq technology by using random primers to simultaneously capture both eukaryotic and bacterial RNAs (scRandom‐seq). Using reference cells, scRandom‐seq can detect individual eukaryotic and bacterial cells with high throughput and high specificity. Acinetobacter baumannii (A.b) is a highly opportunistic and nosocomial pathogen that displays resistance to many antibiotics, posing a significant threat to human health, calling for discoveries and treatment. In the A.b infection model, scRandom‐seq witnessed polarization of THP‐1 derived‐macrophages and the intracellular A.b‐induced ferroptosis‐stress in host cells. The inhibition of ferroptosis by Ferrostatin‐1 (Fer‐1) resulted in the improvement of cell vitality and resistance to A.b infection, indicating the potential to resist related infections. scRandom‐seq provides a high‐throughput cross‐species dual single‐cell RNA profiling tool that will facilitate future discoveries in unraveling the complex interactions of host–microbe interactions in infection systems and tumor micro‐environments. [ABSTRACT FROM AUTHOR]

Interactions between host and bacterial cells are integral to human physiology. The complexity of host–microbe interactions extends to different cell types, spatial aspects, and phenotypic heterogeneity, requiring high‐resolution approaches to capture their full complexity. The latest breakthroughs in single‐cell RNA sequencing (scRNA‐seq) have opened up a new era of studies in host–pathogen interactions. Here, we first report a high‐throughput cross‐species dual scRNA‐seq technology by using random primers to simultaneously capture both eukaryotic and bacterial RNAs (scRandom‐seq). Using reference cells, scRandom‐seq can detect individual eukaryotic and bacterial cells with high throughput and high specificity. Acinetobacter baumannii (A.b) is a highly opportunistic and nosocomial pathogen that displays resistance to many antibiotics, posing a significant threat to human health, calling for discoveries and treatment. In the A.b infection model, scRandom‐seq witnessed polarization of THP‐1 derived‐macrophages and the intracellular A.b‐induced ferroptosis‐stress in host cells. The inhibition of ferroptosis by Ferrostatin‐1 (Fer‐1) resulted in the improvement of cell vitality and resistance to A.b infection, indicating the potential to resist related infections. scRandom‐seq provides a high‐throughput cross‐species dual single‐cell RNA profiling tool that will facilitate future discoveries in unraveling the complex interactions of host–microbe interactions in infection systems and tumor micro‐environments. [ABSTRACT FROM AUTHOR]

Infections caused by Acinetobacter baumannii, a Gram‐negative opportunistic pathogen, are difficult to eradicate due to the bacterium's propensity to quickly gain antibiotic resistances and form biofilms, a protective bacterial multicellular community. The A. baumannii DNA damage response (DDR) mediates the antibiotic resistance acquisition and regulates RecA in an atypical fashion; both RecALow and RecAHigh cell types are formed in response to DNA damage. The findings of this study demonstrate that the levels of RecA can influence formation and dispersal of biofilms. RecA loss results in surface attachment and prominent biofilms, while elevated RecA leads to diminished attachment and dispersal. These findings suggest that the challenge to treat A. baumannii infections may be explained by the induction of the DDR, common during infection, as well as the delicate balance between maintaining biofilms in low RecA cells and promoting mutagenesis and dispersal in high RecA cells. This study underscores the importance of understanding the fundamental biology of bacteria to develop more effective treatments for infections. [ABSTRACT FROM AUTHOR]

The treatment options are limited in Acinetobacter baumannii infections. In this study, the effectiveness of colistin monotherapy and combinations of colistin with different antibiotics were investigated in an experimental pneumonia model induced by carbapenem‐resistant A. baumannii strain. Mice in the study were divided into five groups as control (no treatment), colistin monotherapy, colistin + sulbactam, colistin + imipenem, and colistin + tigecycline combinations. The modified experimental surgical pneumonia model of Esposito and Pennington was applied to all groups. The presence of bacteria in blood and lung samples was investigated. Results were compared. In blood cultures, while there was no difference between the control and colistin groups, there was a statistical difference between the control and the combination groups (P = 0.029). When the groups were compared in terms of lung tissue culture positivity, there was a statistical difference between the control group and all treatment groups (colistin, colistin + sulbactam, colistin + imipenem, and colistin + tigecycline) (P = 0.026, P < 0.001, P < 0.001, and P = 0.002, respectively). The number of microorganisms that grew in the lung tissue was found to be statistically significantly lower in all treatment groups in comparison with the control group (P = 0.001). Both monotherapy and combination therapies of colistin were found to be effective in the treatment of carbapenem‐resistant A. baumannii pneumonia, but the superiority of combination therapies over colistin monotherapy has not been demonstrated. [ABSTRACT FROM AUTHOR]

Carbapenem‐resistant Acinetobacter baumannii (CRAB) is a difficult‐to‐treat nosocomial pathogen responsible for significant morbidity and mortality. Sulbactam‐durlobactam (SUL‐DUR), formerly ETX2514SUL, is a novel β‐lactam‐β‐lactamase inhibitor designed specifically for the treatment of CRAB infections. The United States Food and Drug Administration (FDA) fast‐track approval of SUL‐DUR for the treatment of CRAB infections is currently pending after completion of the phase III ATTACK trial, which compared SUL‐DUR to colistin, both in combination with imipenem‐cilastatin (IMI) for patients with CRAB‐associated hospital‐acquired bacterial pneumonia, ventilator‐associated pneumonia, and bacteremia. The results of this trial demonstrated that SUL‐DUR was non‐inferior to colistin for CRAB while also possessing a much more favorable safety profile. SUL‐DUR was well‐tolerated with the most common side effects being headache, nausea, and injection‐site phlebitis. With the current landscape of limited effective treatment options for CRAB infections, SUL‐DUR represents a promising therapeutic option for the treatment of these severe infections. This review will discuss the pharmacology, spectrum of activity, pharmacokinetics/pharmacodynamics, in vitro and clinical studies, safety, dosing, administration, as well as the potential role in therapy for SUL‐DUR. [ABSTRACT FROM AUTHOR]

Background: Outer membrane protein A (OmpA) is the major virulence factor of Acinetobacter baumannii and plays a wide role in the pathogenesis and antimicrobial resistance of A. baumannii. Dendritic cells (DCs) are the most effective antigen‐presenting cells and play a crucial role in regulating the immune response to multiple antigens and immune sentries. We aimed to study the role and molecular mechanisms of OmpA‐induced mouse bone marrow‐derived dendritic cells (BMDCs) autophagy in the immune response of A. baumannii. Methods: First, purified A. baumannii OmpA was assessed by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) and western blot. OmpA effect on BMDCs viability was evaluated by MTT assay. BMDCs were pretreated with autophagy inhibitor chloroquine or transfected with overexpression plasmids (oe‐NC or oe‐PI3K). Then BMDCs apoptosis, inflammatory cytokines, protein kinase B (PI3K)/mammalian target of rapamycin (mTOR) pathway, and autophagy‐related factors levels were evaluated. Results: SDS‐PAGE and western blot verified the successful purification of OmpA. BMDCs viability repressed gradually with the increase of OmpA concentration. OmpA treatment of BMDCs led to apoptosis and inflammation in BMDCs. OmpA caused incomplete autophagy in BMDCs, and light chain 3 (LC3), Beclin1, P62, and LC3II/I levels were significantly elevated with the increase of the time and concentration of OmpA treatment. Chloroquine reversed OmpA effects on autophagy in BMDCs, that was, LC3, Beclin1, and LC3II/I levels were reduced, while P62 level was elevated. Furthermore, chloroquine reversed OmpA effects on apoptosis and inflammation in BMDCs. PI3K/mTOR pathway‐related factor expression was affected by OmpA treatment of BMDCs. After overexpression of PI3K, these effects were reversed. Conclusions: A. baumannii OmpA induced autophagy in BMDCs involving the PI3K/mTOR pathway. Our study may provide a novel therapeutic target and theoretical basis for treating infections caused by A. baumannii. [ABSTRACT FROM AUTHOR]

In previous studies we have described the therapeutic action of luminescent dinuclear ruthenium(II) complexes based on the tetrapyridylphenazine, tpphz, bridging ligand on pathogenic strains of Escherichia coli and Enterococcus faecalis. Herein, the antimicrobial activity of the complex against pernicious Gram‐negative ESKAPE pathogenic strains of Acinetobacter baumannii (AB12, AB16, AB184 and AB210) and Pseudomonas aeruginosa (PA2017, PA_ 007_ IMP and PA_ 004_ CRCN) are reported. Estimated minimum inhibitory concentrations and minimum bactericidal concentrations for the complexes revealed the complex shows potent activity against all A. baumannii strains, in both glucose defined minimal media and standard nutrient rich Mueller‐Hinton‐II. Although the activity was lower in P. aureginosa, a moderately high potency was observed and retained in carbapenem‐resistant strains. Optical microscopy showed that the compound is rapidly internalized by A. baumannii. As previous reports had revealed the complex exhibited no toxicity in Galleria Mellonella up to concentrations of 80 mg/kg, the ability to clear pathogenic infection within this model was explored. The pathogenic concentrations to the larvae for each bacterium were determined to be≥105 for AB184 and≥103 CFU/mL for PA2017. It was found a single dose of the compound totally cleared a pathogenic A. baumannii infection from all treated G. mellonella within 96 h. Uniquely, in these conditions thanks to the imaging properties of the complex the clearance of the bacteria within the hemolymph of G. mellonella could be directly visualized through both optical and transmission electron microscopy. [ABSTRACT FROM AUTHOR]

Pathogenic Acinetobacter species, most notably Acinetobacter baumannii, are a significant cause of healthcare‐associated infections worldwide. Acinetobacter infections are of particular concern to global health due to the high rates of multidrug resistance and extensive drug resistance. Widespread genome sequencing and analysis has determined that bacterial antibiotic resistance is often acquired and disseminated through the movement of mobile genetic elements, including insertion sequences (IS), transposons, integrons, and conjugative plasmids. In Acinetobacter specifically, resistance to carbapenems and cephalosporins is highly correlated with IS, as many ISAba elements encode strong outwardly facing promoters that are required for sufficient expression of β‐lactamases to confer clinical resistance. Here, we review the role of mobile genetic elements in antibiotic resistance in Acinetobacter species through the framework of the mechanism of resistance acquisition and with a focus on experimentally validated mechanisms. [ABSTRACT FROM AUTHOR]

Objective: Over the past few decades, life expectancy in Brazil has increased from 48 years in 1950s to 76 years in 2017. The aim of this study was to investigate the impact of ageing on: (1) the frequency of hospitalisations due to bloodstream infection (BSI); (2) the incidence of hospital‐acquired BSI (H‐BSI); (3) the incidence of BSI caused by multidrug‐resistant (MDR) agents and (4) the mortality rate of BSI in a public hospital. Methods: A hospital‐based case‐cohort study was conducted between 1 December 2013 and 31 December 2015. The data were analysed using multivariable logistic regression. Results: A total of 500 BSI episodes were detected, among 11,102 hospitalizations. The incidence of hospitalisations resulting from BSI was significantly higher in older than younger patients (3.7/100 vs. 2.0/100, p < 0.01). Similarly, the incidence of hospital‐acquired BSI was significantly higher in older patients (2.7/100 vs. 0.9/100, p < 0.01). Klebsiella pneumoniae (15.9%), Staphylococcus aureus (14.3%), Escherichia coli (13.1%) and Acinetobacter spp. (12.1%) were the most common agents isolated. MDR agents caused 37.6% of the BSI episodes; enteric Gram‐negative bacilli resistant to third‐ or fourth‐generation cephalosporins (9.7%) and carbapenem‐resistant Acinetobacter spp. (9.2%) were the most common MDR agents. The following complications were independently associated with ageing: Charlson comorbidity index (OR = 1.16; 95% CI = 1.09–1.24); BSI secondary to urinary tract infection (OR = 2.14; 95% CI = 1.29–3.55); BSI secondary to pneumonia (OR = 1.77; 95% CI = 1.07–2.93) and 30‐day mortality following BSI (OR = 2.19; 95% CI = 1.43–3.36). Conclusions: These data suggest ageing has a significant impact on hospitalisations due to BSI, H‐BSI incidence and mortality from BSI in older patients attending a Brazilian public hospital. Age was not significantly associated with MDR‐related BSI. These results indicate that age plays an important role in the increase in morbidities and mortality resulting from BSI in Brazil and that with the increased life expectancy observed over recent decades in Brazil, the burden of BSI will be expected to continue to increase. This dynamic needs to be better understood with additional studies. [ABSTRACT FROM AUTHOR]

This review critically appraises the published microbiologic and clinical data on the treatment of patients with carbapenem‐resistant Acinetobacter baumannii infections. Despite being recognized as an urgent threat pathogen by the CDC and WHO, optimal treatment of patients with serious CRAB infections remains ill‐defined. Few commercially available agents exhibit reliable in vitro activity against CRAB. Historically, polymyxins have been the most active agents in vitro, though interpretations of susceptibility data are difficult given issues surrounding MIC testing methodologies and lack of correlation between MICs and clinical outcomes. Most available preclinical and clinical data involve use of polymyxins, tetracyclines, and sulbactam, alone and in combination. As the number of viable treatment options is limited, combination therapy with a polymyxin is often used for patients with CRAB infections, despite the significant risk of nephrotoxicity. However, no treatment regimen has been found to reduce mortality, which exceeds 40% across most studies, or substantially improve clinical response. While some newer agents, such as eravacycline and cefiderocol, have demonstrated in vitro activity, clinical efficacy has not been fully established. New agents with clinically relevant activity against CRAB isolates and favorable toxicity profiles are sorely needed. [ABSTRACT FROM AUTHOR]

Background: The PGDprime® test was updated to enable Acinetobacter spp. detection to respond to morbidity and mortality events in 2018 and 2020 involving platelets contaminated with Acinetobacter-calcoaceticus-baumannii complex (ACBC). In one morbidity event, the first-generation PGD test failed to detect ACBC. In two other reported events, pathogen-reduced (PR) platelets contaminated with ACBC and other bacteria led to patient morbidity and one death.Study Design and Methods: A polyclonal antibody to Acinetobacter was integrated in the test device and evaluated for detection of Acinetobacter spp., including the ACBC isolate recovered in one of the 2018 contamination events. Limits of Detection for various Acinetobacter strains were determined in dilution studies. Detection of Acinetobacter growing in platelets after an initial low inoculum was evaluated. Use of the updated test as a secondary test after pathogen reduction was also evaluated by testing at 12-h intervals PR platelet units inoculated with low levels of the 3 species reported in the fatal PR platelet: ACBC, Staphylococcus saprophyticus, and Leclercia adecarboxylata.Results: The test detected several Acinetobacter strains at the clinically relevant CFU/ml levels associated with septic transfusions and successfully detected Acinetobacter growing in various non-PR platelet types after an initial low inoculum. In PR platelets, the test yielded a positive result with the 3 implicated bacteria in 48 h or less after inoculation, or 48-72 h earlier than the reported time of transfusion of contaminated PR platelets.Conclusion: PGDprime was improved to detect Acinetobacter and has shown utility to interdict contaminated PR platelets. [ABSTRACT FROM AUTHOR]

Surveillance programs have been reporting decreasing rates of carbapenem‐sensitivity in Serratia marcescens, leading to a concern regarding the few remaining therapeutic options to treat these multidrug‐resistant (MDR) organisms. Here, we describe a case series of 11 stem cell hematopoietic transplantation patients infected (N = 6) or colonized (N = 5) by carbapenem‐resistant S marcescens (CrSm) from 2010 to 2013. The comorbidities found were acute renal insufficiency (3/11), neutropenia (7/11), and mucositis (8/11), and the mortality rate was 64%. KPC was the most prevalent carbapenemase detected (8/11) and tigecycline and gentamicin were the antimicrobials used as treatment. [ABSTRACT FROM AUTHOR]

We report the case of a 53-year-old male that presented to our hospital with a history of a brain tumour. He was hospitalized 10 days prior in another hospital. Before surgery, he complained of mild cough. Routine chest radiography demonstrated right upper lobe consolidation which was diagnosed as hospital-acquired pneumonia. Broad-spectrum empirical antimicrobial was initiated. After surgery, his clinical condition deteriorated and he felt breathlessness. Chest radiography and computed tomography (CT) scan without contrast revealed necrotizing and cavitating pneumonia complicated by bronchopleural fistula (BPF) and hydropneumothorax. Sputum culture revealed infection of multidrug-resistant Acinetobacter baumannii (MDRAB). Despite optimal antibiotic therapy, BPF and hydropneumothorax failed to resolve and surgical approach was performed to debride the necrotic area and seal the fistula. After a month in the hospital, he was discharged and the serial chest X-ray showed good recovery of the lung. [ABSTRACT FROM AUTHOR]

Acinetobacter baumannii, one of the most life‐threatening nosocomial drug‐resistant pathogens, imposes high morbidity and mortality rates, thus highlighting immunization‐based treatments or prevention measures. The selection of appropriate antigens can elicit protective immunity. The gene encoding a fimbrial protein introduced via reverse vaccinology was cloned, expressed and evaluated for immunogenicity in a murine model. Mice immunized with the recombinant protein were challenged with A. baumannii ATCC 19606. Adherence to A549 cell line of specific anti‐sera treated A. baumannii was also assessed. Passive immunity was evaluated in a murine pneumonia model. Indirect ELISA showed a high specific antibody titre. Adherence of A. baumannii to A549 cell line decreased by 40% after incubation with 1:250 dilution of specific anti‐sera. All the actively immunized mice survived. Bacterial load in the spleen and liver of the immunized mice was 3‐fold lower than those of the control. The number of bacteria in the lungs of passively immunized mice was about 6‐fold lower than the control mice. The fimbrial protein could be considered as a promising protective immunogen against A. baumannii. [ABSTRACT FROM AUTHOR]

Bordetella avium pneumonia immunocompromised the patient with subsequent complication by a rare opportunistic Raoultella planticola infection, which became a nosocomial pathogen in the healthcare setting. [ABSTRACT FROM AUTHOR]

Extracellular capsule polysaccharides increase the cellular fitness under abiotic stresses and during competition with other bacteria. They are best‐known for their role in virulence, particularly in human hosts. Specifically, capsules facilitate tissue invasion by enhancing bacterial evasion from phagocytosis and protect cells from biocidal molecules. Klebsiella pneumoniae is a worrisome nosocomial pathogen with few known virulence factors, but the most important one is its capsule. In this issue, Tan et al. assess the fitness advantage of the capsule by competing a wild‐type strain against four different mutants where capsule production is interrupted at different stages of the biosynthetic pathway. Strikingly, not all mutants provide a fitness advantage. They suggest that some mutants have secondary defects altering virulence‐associated phenotypes and blurring the role of the capsule in pathogenesis. This study indicates that the K1 capsule in K. pneumoniae is not required for gut colonization but that it is critical for bloodstream dissemination to other organs. These results contribute to clarify the contradictory literature on the role of the Klebsiella capsule during infection. Finally, the varying fitness effects of different capsule mutations observed for K. pneumoniae K1 might apply also to other capsulated diderm bacteria that are facultative or emerging pathogens. [ABSTRACT FROM AUTHOR]

Background: We hypothesized that children treated in adult intensive care units (ICUs) might be at increased risk of hospital‐acquired infection. We therefore compared the incidence of Acinetobacter baumannii infection in children treated in pediatric ICUs (PICUs) and in those treated in adult ICUs. Methods: Patients aged <18 years admitted to PICUs or adult ICUs between March 2009 and June 2017 were enrolled. We retrospectively investigated A. baumannii isolates and calculated the A. baumannii incidence during ICU admission. Cox regression was used to identify possible risk factors for A. baumannii infection. Results: Eight hundred and thirty ICU cases were included; 508 were treated in PICUs ("PICU group") and 322 in adult ICUs ("adult‐ICU group"). Acinetobacter baumannii was isolated 19 (3.7%) and 23 (7.1%) times in the PICU and adult‐ICU groups, respectively. Incidence densities for A. baumannii acquisition in PICU and adult‐ICU groups were 1.63 and 5.62 per 1,000 ICU days, respectively. In the Cox regression model, the hazard ratio for A. baumannii acquisition associated with treatment in PICUs was 0.33 (95% confidence interval: 0.17–0.61; P = 0.001). In multivariate analysis after adjusting for age and sex, treatment in PICU remained significantly associated with a reduced risk of A. baumannii infection (hazard ratio: 0.40; 95%; confidence interval: 0.20–0.76). Conclusions: Pediatric patients treated in a PICU had a lower rate and incidence density of A. baumannii nosocomial infection than those treated in adult ICUs, suggesting that PICUs provide better infection control for children than adult ICUs. [ABSTRACT FROM AUTHOR]

Iron uptake system is expressed in early stages of Acinetobacter baumannii infections under iron‐restricted conditions. This study is aimed at the evaluation of immuno‐protectivity of BfnH in comparison with BauA in both mature and selected fragmental proteins. The study was designed in single and combined forms of antigens. BfnH is presented in 3472 strains of A. baumannii with more than 97% identity. The preliminary immune‐informatics analysis of this protein indicated a region from the β‐barrel domain including exposed loops 2–5, with antigenic score comparable to that of BfnH. There was a significant rise in the specific IgG response in all test groups. The bacterial challenge with a lethal dose of A. baumannii demonstrated partial protection of whole proteins which coincides with a significant reduction in the bacterial population colonized in the main organs and an increase in the survival level. Passive immunization of the mice brought about 50% survival in the mice groups immunized with BfnH and with a combination of BfnH and BauA. The protectivity of siderophore receptors suggests their potential immunogenic role that could be considered as a component of multivalent subunit vaccine candidates against A. baumannii. [ABSTRACT FROM AUTHOR]

Aim: The aim of the present study was to investigate predominant pathogens and predictors of 28‐day mortality of older Chinese patients with nosocomial urinary tract infections (NUTI). Methods: We retrospectively studied 1122 older patients (aged ≥60 years) with culture‐positive NUTI in Guangdong General Hospital, Guangzhou, China, from January 2009 to December 2014. The clinical features, microbial distributions and outcomes of these patients were recorded and compared between survival and death patients. Multivariate logistic regression was carried out to identify independent predictors of 28‐day mortality. Results: The present results showed the all‐cause mortality was 8.3%, and NUTI mortality was 1.43%. The proportions of Candida albicans (P = 0.004), Acinetobacter baumannii (P = 0.045) and Candida tropicalis (P < 0.001) in the death group were significantly higher than those in the survival group. Multivariate analysis showed two novel risk factors for mortality of older patients with NUTI, which were higher Charlson Comorbidity Index (odds ratio [OR] 1.205, 95% confidence interval (CI) 1.088–1.334] and lower level of serum prealbumin (OR 0.995, 95% CI 0.990–0.999). Furthermore, previous use of antibiotics (OR 1.984, 95% CI 1.106–3.559), inappropriate antimicrobial therapy (OR 1.883, 95% CI 1.144–3.098), intensive care unit stay (OR 4.082, 95% CI 2.469–6.749) and higher concentration of serum C‐reactive protein (OR 1.005, 95% CI 1.001–1.010) were independent prognostic factors for 28‐day mortality in older patients with NUTI. Conclusions: NUTI is associated with a high 28‐day in‐hospital mortality rate in older patients. We should evaluate the comorbidity, nutritional status, inflammatory markers, department staying and drug sensitivity test, and choose systematic therapy strategies for these older patients with NUTI. Geriatr Gerontol Int 2019; 19: 541–546. [ABSTRACT FROM AUTHOR]

The article presents a case study of 17-year-old male teenager. It mentions that bone histopathology revealed unspecific inflammation; acid-fast staining and mycobacterial nucleic acid amplification test were negative, and culture was positive for extended spectrum beta lactamase (ESBL)-producing Klebsiella pneumonia.

Asymmetry in the outer membrane has long defined the cell envelope of Gram-negative bacteria. This asymmetry, with lipopolysaccharide (LPS) or lipooligosaccharide (LOS) exclusively in the outer leaflet of the membrane, establishes an impermeable barrier that protects the cell from a number of stressors in the environment. Work done over the past 5 years has shown that Acinetobacter baumannii has the remarkable capability to survive with inactivated production of lipid A biosynthesis and the absence of LOS in its outer membrane. The implications of LOS-deficient A. baumannii are far-reaching - from impacts on cell envelope biogenesis and maintenance, bacterial physiology, antibiotic resistance and virulence. This review examines recent work that has contributed to our understanding of LOS-deficiency and compares it to studies done on Neisseria meningitidis and Moraxella catarrhalis; the two other organisms with this capability. [ABSTRACT FROM AUTHOR]

Aim: This study assessed the efficacy and safety of tigecycline in children with life-threatening infections.Methods: We retrospectively reviewed the clinical records of patients treated with tigecycline from June 2012 to May 2014 in a Chinese tertiary centre.Results: The study comprised 24 patients (14 male) with a median age of four years (range, 50 days-12 years). The most frequently isolated microorganism, most common isolation site and type of infection were Acinetobacter baumannii, tracheal aspirate fluid and ventilator-associated pneumonia, respectively. Tigecycline was administered at a loading dose of 1.5 or 2.0 mg/kg and 1.0 mg/kg every 12 hours after that. The average duration of treatment was 11.6 ± 5.8 days. The clinical response and microbiological eradication rate were 37.5% and 29.2%, respectively. Six of the patients we studied (25.0%) died, and three of these deaths were considered to be infection related. Adverse drug reactions were identified in four patients (16.7%) during the treatment, including abnormal liver function, prolonged prothrombin time and diarrhoea.Conclusion: Our findings suggest that tigecycline may be an option for children with severe infections. However, more prospective, controlled trials are required to objectively evaluate the efficacy and safety of tigecycline in children. [ABSTRACT FROM AUTHOR]

O6-1: A multi-epitope peptide rOmp22 encapsulated in chitosan-PLGA nanoparticles as vaccine candidate against Acinetobacter baumannii infection Compared with nonencapsulated rOmp22, CS-PLGA-rOmp22 immunized BALB/c mice induced higher levels of rOmp22-specific IgG in serum and IFN- in splenocyte supernatant. Then, rOmp22 was encapsulated by chitosan (CS) and poly (lactic-co-glycolic) acid (PLGA) to prepare CS-PLGA-rOmp22 nanoparticles (NPs). [Extracted from the article]

O6-1: A multi-epitope peptide rOmp22 encapsulated in chitosan-PLGA nanoparticles as vaccine candidate against Acinetobacter baumannii infection Compared with nonencapsulated rOmp22, CS-PLGA-rOmp22 immunized BALB/c mice induced higher levels of rOmp22-specific IgG in serum and IFN- in splenocyte supernatant. Then, rOmp22 was encapsulated by chitosan (CS) and poly (lactic-co-glycolic) acid (PLGA) to prepare CS-PLGA-rOmp22 nanoparticles (NPs). [Extracted from the article]

Background and objective A cinetobacter baumannii and A . baumannii/calcoaceticus complex are commonly encountered pathogens in nosocomial infections. This study aimed to evaluate the treatment and prognostic risk factors in nosocomial pneumonia caused by these microorganisms. Methods The study was conducted retrospectively in Uludag University Hospital and included 356 adult non-neutropenic patients with nosocomial pneumonia. Results Of the subjects, 94.9% ( n = 338) had ventilator-associated pneumonia. The clinical response rate was 57.2%, the 14-day mortality 39.6% and the 30-day mortality 53.1%. The significant independent risk factors for the 30-day mortality were severe sepsis ( OR, 2.60; 95% CI: 1.49-4.56; P = 0.001), septic shock ( OR, 6.12; 95% CI: 2.75-13.64; P < 0.001), APACHE II score ≥ 20 ( OR, 2.12; 95% CI: 1.28-3.50; P = 0.003) and empiric monotherapy ( OR, 1.63; 95% CI: 1.00-2.64; P = 0.048). Multi-trauma ( OR, 2.50; 95% CI: 1.11-5.68; P = 0.028) was found to be a protective factor. In patients with a clinical pulmonary infection score ( CPIS) > 6 on the third day of treatment, both the 14- and 30-day mortality rates were high ( P < 0.001, P < 0.001). Also, the 14- and 30-day mortality rates were significantly higher in the patients treated with empiric monotherapy compared with combination therapy (48/93 (51.6%)-46/123 (37.4%), P = 0.037 and 62/93 (66.7%)-65/123 (52.8%), P = 0.041, respectively) in pneumonia caused by imipenem-resistant strains. Conclusion Mortality rates were high in pneumonia caused by imipenem-resistant A . baumannii or A . baumannii/calcoaceticus complex. In the units with a high level of carbapenem resistance, antibiotic combinations should be considered for empiric therapy. [ABSTRACT FROM AUTHOR]

In light of the paucity of literature, we write to illustrate the clinical impact of I A. baumannii i infection in a paediatric patient with I CF i . The patient, who is heterozygous for G27X/2622 + 1G > A mutation, attended a routine clinic in June 2018 with weight loss, ppFEV SB 1 sb below baseline and an increased Lung Clearance Index (LCI). It is therefore reasonable to assume that I A. baumannii i has an occult, pathogen-mediated, impact on the small airways resulting in clinical symptoms and reduced ventilation homogeneity in paediatric patients with I CF i . [Extracted from the article]

To investigate the correlation between carbapenem consumption and rates of antimicrobial resistance in Acinetobacter baumannii, carbapenem consumption was expressed as defined daily dose based on the World Health Organization (WHO) anatomical therapeutic chemical classification index. Clinical isolates from 2001-2009 were collected and analyzed using WHONET 5.4 software. Results show that the consumption of imipenem/cilastatin, meropenem, and total carbapenem is significantly correlated with imipenem resistance in A baumannii ( r = 0.818, P = .007; r = 0.817, P = .007; r = 0.827, P = .006). Furthermore, total carbapenem consumption is significantly correlated with meropenem resistance in A baumannii ( r = 0.900, P = .037). In addition, consumption of imipenem/cilastatin, meropenem, and total carbapenem is associated with A baumannii resistance to piperacillin-tazobactam, ceftazidime, cefepime, amikacin, and levofloxacin. These drugs are mainly β-lactams, aminoglycosides, and fluoroquinolones. The imipenem and meropenem resistance rates are significantly correlated with resistance rates to numerous antimicrobial drugs (eg, β-lactams, aminoglycosides, and fluoroquinolones) in A baumannii. Therefore, increased consumption of carbapenem may contribute to the development of resistance in A baumannii to imipenem, meropenem, and other antimicrobial drugs. Cross-resistance possibly occurs among imipenem/cilastatin and meropenem, as well as with β-lactams, aminoglycosides, and fluoroquinolones. [ABSTRACT FROM AUTHOR]

Background: Seventeen cases of Acinetobacter baumannii infection in a neonatal intensive care unit (NICU) were evaluated. The strains were characterized as resistant to carbapenems. The aim of the present study was therefore to investigate the clinical and molecular epidemiological characteristics of the 17 carbapenem-resistant A. baumannii strains. Methods: Samples were isolated from blood or sputum from the patients in the NICU, cultured using conventional techniques and an automated system. Multiplex polymerase chain reaction (PCR) was used to detect blaOXA-51-like, blaOXA-23-like, OXA-24, OXA-58 and Ambler class B carbapenemases. The genotype of the strains was identified on pulsed-field gel electrophoresis (PFGE). Results: BlaOXA-23 was detected in all of the isolates. PFGE genotype analysis suggested three clones among the 17 strains. Two clones were isolated from other wards of the hospital including the adult ICU and Department of Pulmonology. The other clone was proved to be the first appearance in the hospital as genotype analysis. Conclusion: BlaOXA-23 was the drug-resistant gene that made A. baumannii resistant to carbepenem. The source of blaOXA-23 in the 17 isolates was different. [ABSTRACT FROM AUTHOR]

The genus Acinetobacter comprises a complex and heterogeneous group of bacteria, many of which are capable of causing a range of opportunistic, often catheter-related, infections in humans. However, Acinetobacter baumannii, as well as its close relatives belonging to genomic species 3 (' Acinetobacter pittii') and 13TU (' Acinetobacter nosocomialis'), are important nosocomial pathogens, often associated with epidemic outbreaks of infection, that are only rarely found outside of a clinical setting. These organisms are frequently pandrug-resistant and are capable of causing substantial morbidity and mortality in patients with severe underlying disease, both in the hospital and in the community. Several epidemic clonal lineages of A. baumannii have disseminated worldwide and seem to have a selective advantage over non-epidemic strains. The reasons for the success of these epidemic lineages remain to be elucidated, but could be related to the potential of these organisms to achieve very dynamic reorganization and rapid evolution of their genome, including the acquisition and expression of additional antibiotic resistance determinants, under fluctuating environmental and selective conditions. © 2011 IUBMB IUBMB Life, 63(12): 1048-1054, 2011 [ABSTRACT FROM AUTHOR]

Acinetobacter spp., source of numerous nosocomial infections, deserves a close attention as various multidrug resistance strains are being discovered worldwide. Acinetobacter baylyi is chosen because of its high competence for natural transformation, and its ability to undergo direct homology-based recombination. An in silico comparative analysis of the metabolic pathways of the host Homo sapiens and the pathogen Acinetobacter baylyi was performed by using BLASTp search. This search is against the non-redundant database restricted to the Homo sapiens subset. Sixteen unique pathways identified enlisted a total of 183 drug targets of which 31 belong to the metabolic pathways unique to pathogen having no human homolog. Of these potential drug targets enlisted, RmlA enzyme ( d-glucose-1 phosphate thymidylyltransferase) is the first enzyme in the polyketide sugar unit synthesis metabolic pathway, which leads to the formation of l-rhamnose. In gram-negative bacteria, l-rhamnose is one of the important residues of the O-antigen of lipopolysaccharide, a key determinant factor for the virulence of these species. Moreover, these proteins are highly conserved among microorganisms, and therefore, conclusions drawn from the structure of a protein from one species will have strong implications for the corresponding enzyme structure of another origin. Homology modeling of RmlA was performed by MODELLER and the PMDB ID obtained is PM0076419. Further, molecular docking studies were performed for RmlA, which might aid drug design for nosocomial infections. [ABSTRACT FROM AUTHOR]

Background: The aim of the present study was to explore the incidence and risk factors of, and summarize the involved pathogens in, neonates with ventilator-associated pneumonia (VAP) in the authors' neonatal intensive care unit (NICU) to determine the effective strategies for prevention. Methods: A retrospective case-control study including 117 VAP patients and 232 controls was conducted from January 2002 to July 2008. The antibiotics sensitivity spectrum was determined on quantitative microbiological evaluation. Multiple logistic regression and Cox model analysis were performed to determine independent and accumulative risk factors for VAP. Results: Multivariate analysis showed that birthweight, mechanical ventilation (MV), parenteral alimentation, dexamethasone and other respiratory disease were associated with the development of VAP. The cumulative risk for developing VAP increased over the duration of stay in the NICU. The most common isolated bacteria of the pathogen spectrum in VAP were Klebsiella spp. (33/146), Acinetobacter baumannii (26/146), Pseudomonas aeruginosa (18/146) and Staphylococcus aureus(13/146). Meanwhile, we found that previous use of antibiotics before VAP diagnosis was not associated with the onset of VAP. Conclusions: The daily risk for VAP increases with duration of stay in the NICU after ventilation. Drug-resistant bacteria are common pathogens for neonatal VAP in the authors' NICU. [ABSTRACT FROM AUTHOR]

Colistin is a polymyxin antibiotic that was discovered in the late 1940s for the treatment of gram-negative infections. After several years of clinical use, its popularity diminished because of reports of significant nephrotoxicity and neurotoxicity. Recently, the antibiotic has resurfaced as a last-line treatment option for multidrug-resistant organisms such as Pseudomonas aeruginosa, Acinetobacler baumannii, and Klebsiella pneumoniae. The need for antibiotics with coverage of these gram-negative pathogens is critical because of their high morbidity and mortality, making colistin a very important treatment option. Unfortunately, however, resistance to colistin has been documented among all three of these organisms in case reports. Although the exact mechanism causing colistin resistance has not been defined, it is hypothesized that the PmrA-PmrB and PhoP-PhoQ genetic regulatory systems may play a role. Colistin dosages must be optimized, as colistin is a last-line treatment option; in addition, suboptimal doses have been linked to the development of resistance. The lack of pharmacokinetic and pharmacodynamic studies and no universal harmonization of dose units, however, have made it difficult to derive optimal dosing regimens and specific dosing guidelines for colistin. In critically ill patients who may have multiorgan failure, renal insufficiency may alter colistin pharmacokinetics. Therefore, dosage alterations in this patient population are imperative to achieve maximal efficacy and minimal toxicity. With regard to colistin toxicity, most studies show that nephrotoxicity is reversible and less frequent than once thought, and neurotoxicity is rare. Further research is needed to fully understand the impact that the two regulatory systems have on resistance, as well as the dosages of colistin needed to inhibit and overcome these developing patterns. [ABSTRACT FROM AUTHOR]

Summary This report describes a case of a multiple-drug resistant strain of Acinetobacter baumannii associated with bronchopneumonia in a horse. A 6-month-old Thoroughbred colt was examined for a chronic lower respiratory tract disease. Prior to presentation to the University Veterinary Teaching Hospital (UVTH), the colt had been treated intensively in a private equine hospital for presumed antimicrobial-induced enterocolitis following treatment with azithromycin and rifampin, and had been discharged on treatment of doxycycline for continued lower airway abnormalities. At the UVTH, investigation of the lower airway disease included a culture of a percutaneous transtracheal wash, which identified a multiple-drug resistant strain of A. baumannii as the causative agent with sensitivity only to fluoroquinolones and trimethoprim sulphonamides. Following treatment with marbofloxacin there was full resolution of the bronchopneumonia. A. baumannii is a major nosocomial pathogen associated with infections in both animals and man and reports of multiple-drug resistant strains have been documented worldwide. Outbreaks of A. baumannii infections have been reported to occur in very ill human patients housed in healthcare settings such as intensive care units, and are characterised by the rapid development of resistance to the majority of antimicrobials. The difficulties in the treatment of such cases as well as the potential risk of transmission within a veterinary clinical setting are discussed. [ABSTRACT FROM AUTHOR]

Aim: The aim of the present study was to assess the efficacy and safety of colistimethate sodium therapy in multidrug-resistant nosocomial infections caused by Pseudomonas aeruginosa or Acinetobacter baumannii in neonates and children. Methods: Pediatric patients hospitalized at the Uludag University Hospital who had nosocomial infections caused by multidrug-resistant P. aeruginosa or A. baumannii, were enrolled in the study. Colistimethate sodium at a dosage of 50–75 × 103 U/kg per day was given i.v. divided into three doses. Results: Fifteen patients received 17 courses of colistimethate sodium for the following infections: ventilator-associated pneumonia ( n= 14), catheter-related sepsis ( n= 1) and skin and soft-tissue infection ( n= 2). The mean age of patients was 53.2 + 74.7 months (range, 8 days–15 years) and 60% were male. Mortality was 26.6%. Conclusion: Colistimethate sodium appears to be safe and effective for the treatment of severe infections caused by multidrug-resistant P. aeruginosa or A. baumannii in pediatric patients. [ABSTRACT FROM AUTHOR]

Background: Bacterial meningitis is a devastating infection with a high mortality rate, especially in neonates. The aim of this study was to determine the causative agents that cause bacterial meningitis in Khuzestan province in the south-western region of Iran. Methods: A descriptive, cross-sectional study was carried out from 1997 to 2007 at the neonatal ward of a university teaching hospital (Emam Khomeini hospital) in Ahvaz. All infants younger than 29 days old who suffered from meningitis were included. Laboratory tests included Gram stain, culture, and biochemical tests. Cases were defined as meningitis if the cerebrospinal fluid culture was positive. Results: Based on cerebrospinal fluid culture, 31 infants were identified as having bacterial meningitis. Eleven (35.5%) of these cases were caused by Klebsiella pneumoniae, nine (29%) were caused by Enterobacter spp., three (9.6%) were caused by Escherichia coli, three (9.6%) were caused by Enterococcus spp., two (6.4 %) were caused by Acinetobacter, and one case each (3.2%) was caused by Staphylococcus aureus, Pseudomonas aeruginosa and nontypeable Haemophilus influenzae. The male-to-female ratio was 2 : 1 (67.7% were male). The birthweights of 20 (64.5%) patients were under 2500 g and 11 (35.4%) patients had normal birthweights. Thirteen (42%) were early-onset cases and 18 (58%) were late-onset cases. More than half of the cases (54.8%) acquired the infection from the hospital. Blood cultures were positive for 18 (58%) patients. Thirty-two percent of cases died in spite of treatment. Conclusions: Klebsiella pneumoniae and Enterobacter spp. were the two main causative agents that caused neonatal bacterial meningitis, and nosocomial meningitis was the most common type in our ward. [ABSTRACT FROM AUTHOR]

This paper discusses a 26-year-old woman with end-stage renal disease on hemodialysis and Acinetobacter calcoaceticus-baumannii complex endocarditis. The patient had an indwelling right internal jugular catheter that was probably the nidus of infection. Transthoracic echocardiogram revealed an atypical presentation of the endocarditis as a large intracardiac mass, measuring in centimeters and occupying more than 50% of the right atrial cavity. The mass was attached to the lateral wall of the right atrium without valvular involvement. The patient was treated with prompt removal of the indwelling catheter, intravenous antibiotics, and surgical resection of the mass with an uneventful recovery. A literature search for cases of “Acinetobacter endocarditis” reveals this as the first case reported of Acinetobacter endocarditis presenting in this manner. (Echocardiography 2010;27:E39-E42) [ABSTRACT FROM AUTHOR]

Background and Objectives Packed red blood cell transfusion has been associated with increased infection in a variety of critically ill patient populations. We evaluated the microbiology and time course of infection in transfused patients in the intensive care unit (ICU) as no data exist on these parameters. Materials and Methods We performed a retrospective review of data for all patients admitted to a 24-bed medical-surgical ICU at Cooper University Hospital from July 2003 to September 2006 and entered in the Project Impact database. Results A total of 2432 patients were admitted during the study period, of which 609 underwent transfusion. Transfused patients were more likely to develop a nosocomial infection (10·5% vs. 4·9%, P < 0·001). ICU and hospital length of stay were longer in the transfused group ( P < 0·001 for both). Mortality was also greater (13·1% vs. 8·7%, P = 0·001). Transfused patients had a shorter time from hospital admission to first infection ( P < 0·001) and ICU admission to first infection ( P < 0·001). Multivariate analysis confirmed transfusion as an independent risk factor for infection, mortality, hospital and ICU length of stay. Methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococcus and Acinetobacter occurred more often in transfused patients. Acinetobacter accounted for a disproportionate share of infections among transfused patients ( P < 0·001). Conclusions Transfused ICU patients have a higher incidence of nosocomial infection and worse outcomes. Transfused patients had a shorter onset of infection. Acinetobacter infection appears to be particularly common among these patients. Further investigation is merited to better elucidate the mechanism for these findings and their therapeutic and clinical implications. [ABSTRACT FROM AUTHOR]

Background and objective: Patients with community-acquired Acinetobacter baumannii (AB) pneumonia have been reported from subtropical countries. We investigated the epidemiology, clinical and microbiological characteristics of community-acquired pneumonia (CAP) due to AB in Singapore. Method: A retrospective case series was performed over a 21-month period at two institutions. Results: From 1 January 2007 to 30 September 2008, eight patients were diagnosed with CAP due to AB. Seven had bacteraemia and five were sputum culture-positive. The median age at presentation was 58.5 years (range 45–76 years). Five patients (71.4%) acquired the pneumonia in the warmer months of June to September. Presentation was acute, with a median duration of 2.5 days (range 1–7 days). The median Acute Physiology and Chronic Health Evaluation II score was 28.5 (range 6–36). Six patients presented with septic shock, lactic acidosis, acute kidney injury and respiratory failure, necessitating ICU care; five of thesepatients eventually died. All patients received empirical antibiotics, including third-generation cephalosporins, which were inactive against the organism. All isolates were susceptible to ampicillin/sulbactam, ciprofloxacin, co-trimoxazole, aminoglycosides and imipenem. Conclusions: Community-acquired AB pneumonia have a fulminant course. In a region endemic for melioidosis and severe community-acquired Klebsiella pneumoniae, the challenge lies in rapid identification and initiation of appropriate empirical antibiotics to improve the survival of patients with AB CAP. [ABSTRACT FROM AUTHOR]

Brucellosis continues to be an important cause of fever in underdeveloped countries and in rural areas of developed world. It is a multisystemic disease, associated with wide variety of symptoms. A wide variety of symptoms, including haematological abnormalities, such as anaemia, thrombocytopenia, pancytopenia, dissemine intravascular coagulation and leucopoenia could be seen, all of which are more common than usually thought. In this short study, we present a relatively uncommon haematological manifestation that of isolated thrombocytopenia mimicking idiopathic thrombocytopenic purpura, which we observed in seven of 114 patients who were diagnosed with brucellosis in our hospital over a 2-year period. Having given brucellosis treatment with rifampicin and doxycycline, complete remission was achieved and thrombocyte count returned to normal in all cases. [ABSTRACT FROM AUTHOR]

Infections caused by multidrug-resistant Acinetobacter baumannii have become a therapeutic challenge for clinicians worldwide. Although colistin and tigecycline have been successful in treating patients with these infections, these agents are not available on a worldwide basis. We describe four critically ill patients in Taiwan who were diagnosed with multidrug-resistant Acinetobacter baumannii bacteremia. All bacterial isolates from these patients were resistant to commonly available antibiotics, including carbapenems and sulbactam; however, combination therapy with a carbapenem and sulbactam led to favorable clinical outcomes in all four patients. We also conducted an in vitro study using isolates from these patients that showed that this drug combination had a synergistic effect with enhanced antibacterial activity against the isolates. Thus, a carbapenem-sulbactam combination may be a therapeutic alternative for multidrug-resistant Acinetobacter baumannii bacteremia in countries where colistin and tigecycline are not available for clinical use. [ABSTRACT FROM AUTHOR]

A 53-year-old woman experienced a multidrug-resistant (MDR) Acinetobacter baumannii urinary tract infection 5 months after undergoing kidney and liver transplantation. The tigecycline minimum inhibitory concentration (MIC) for her A. baumannii isolate was 1.5 µg/ml; the patient received 2 weeks of therapy with intravenous tigecycline as a 100-mg loading dose followed by 50 mg every 12 hours, with no lapses in treatment and with resolution of the infection. Three weeks later, MDR A. baumannii was isolated from her sputum in the setting of clinical evidence of pneumonia, and tigecycline was restarted; the tigecycline MIC for the A. baumannii isolate was 2 µg/ml. At approximately the same time, the patient was found to have a paraspinal abscess and spinal osteomyelitis. Cultures of the abscess fluid grew A. baumannii with a tigecycline MIC of 24 µg/ml. A follow-up sputum culture again yielded A. baumannii, but with a tigecycline MIC of 24 µg/ml. Urine culture at that time also grew A. baumannii with a tigecycline MIC of 24 µg/ml. Clinicians should be aware that tigecycline MICs for A. baumannii isolates may increase during therapy with tigecycline after only brief exposure to the drug. Patients receiving tigecycline for Acinetobacter should be monitored for the development of clinical resistance, and isolates should be monitored for evidence of microbiologic resistance. [ABSTRACT FROM AUTHOR]

Acinetobacter calcoaceticus ADP1 possesses a bifunctional wax ester synthase/acyl-CoA:diacylglycerol acyltransferase (WS/DGAT) catalyzing the biosynthesis of wax esters and triacylglycerols. The unspecificity of WS/DGAT was used for in vitro and in vivo biosynthesis of wax diesters consisting of 1, 16-hexadecanediol esterified with longchain fatty acids. An in vitro assay employing the membrane fraction of recombinant Escherichia coli XL1-Blue expressing wax/dgat coding for WS/DGAT and using 1, 16-hexadecanediol and 1-14 C-palmitoyl-CoA as substrates resulted in the production of 2 radiolabeled substances as revealed by autoradiography suggesting the acylation of one or both hydroxy groups of 1, 16-hexadecanediol by WS/DGAT. For in vivo biosynthesis of wax diesters, the knock-out mutant A. calcoaceticus ADP1acr1 | Km was generated by disruption of acr1 coding for acyl-CoA reductase which caused the inability to synthesize fatty alcohols and, thus in consequence, wax esters. Co-cultivation of A. calcoaceticus ADP1acr1 | Km on gluconate and 1, 16-hexadecanediol in nitrogen-limited mineral salts medium resulted in the accumulation of a mixture of wax diesters of 1, 16-hexadecanediol esterified with palmitic and oleic acid as revealed by electron impact ionization mass spectrometry. 1-Monopalmitoylglycerol could also be utilized as an alternative acyl acceptor by the unspecific WS/DGAT in vitro resulting in the synthesis of 1, 2- and 1, 3-dipalmitoylglycerol, whereas 1-oleoylglycerol-3-phosphate (lysophosphatidic acid) was not accepted. [ABSTRACT FROM AUTHOR]

Summary Acinetobacter baumannii is a significant problem in critically ill patients. It is widespread, can colonise patients quickly and causes virulent infections. However, its overall impact on morbidity and mortality in the critically ill remains unmeasured. This study was designed to investigate A. baumannii colonisation and infection rates in a critically ill population over an 18-month period. Twenty-seven patients from a population of 347 were identified as having A. baumannii . Sixteen were colonised, whereas 11 were infected. Eleven of the 27 patients with A. baumannii died (41%). Of these, eight were colonised and three were infected. In the same period, 320 patients did not have A. baumannii and their mortality rate was 20% (n = 64). The mortality rate of patients with A. baumannii was significantly higher than that of patients without infection. [ABSTRACT FROM AUTHOR]

The article presents a research on total synthesis of acinetobactin. It states that key heterocyclic rings, namely oxazoline and imidazole, were constructed by a Molybdenum (IV) oxide-catalyzed dehydrative cyclization and a Copper (2+) promoted multi-component condensation. It reports about the preparation of structural analogs of acinetobactin and potent acinetobactin drug conjugates effective in treating drug-resistant A. baumannii.

Acinetobacter junii caused sepsis in six preterm infants in our neonatal unit within 48 h. Each infant with clinical signs of systemic infection and activation of the acute phase response had two positive blood cultures with Acinetobacter junii. The sudden onset, the short duration of the outbreak and the fact that none of the infants were colonized by A. junii suggested a common source of A. junii administered directly into the blood. The only feature shared by all six affected newborns was an intravenous fat emulsion (Intralipid 10%), which was shown to be an excellent growth medium for A. junii. Sepsis did not occur in four infants with 20% fat emulsion or amino acids only. Vaminolact[sup ®] did not support growth of the outbreak strain. The immediate source of the outbreak could not be identified: samples of the actual feeds given were not available for investigation, but A. junii was not isolated from parenteral solutions with identical batch numbers used in the septic infants. We conclude that Acinetobacter junii can cause a life-threatening infection in preterm neonates. Contaminated intravenous fat emulsion is implicated as a possible source of the infection. As a part of rigid infection control, intravenous feedings should be prepared under aseptic conditions. [ABSTRACT FROM AUTHOR]

In this article the author reflects upon the issue of multiple drug resistance (MDR) bacteria in equine veterinary medicine. The author discusses various bacterial infections found in horses which Acinetobacter and Methicillin-resistant Staphylococcus aureus (MRSA) and mentions the use of antimicrobials in the treatment of MDR infection. The author offers tips for managing MDR infections which include sample testing for sensitivity, and considering pathogen factors, and possible side effects.

A letter to the editor is presented which is concerned with the case of a 51 year old female patient who developed acinetobacter bacteremia following agkistrodon envenoming.

The article discusses the therapeutic challenge posted by an opportunistic pathogen known as Acinetobacter calcoaceticus-baumannii complex. It presents a case of a 3-year-old boy diagnosed with multidrug-resistant Acinetobacter meningitis after experiencing fever for 5 days. Moreover, it describes the antibiotic susceptibility of Acinetobacter according to the type of drugs given to the patient and proved that colistin is effective.

Morphology and staining properties of Acinetobacter baumannii, by P. Visca, H. Seifert and K.J. Towner, pp. 1048-1054. [ABSTRACT FROM AUTHOR]