Cytokine and cytokine receptor polymorphisms in infectious disease

Host immune responses strongly control the outcome of infectious disease, and the resistance to bacterial infections in humans is in part genetically determined. Responses to Gram-negative bacterial endotoxin are affected by the concentration of plasma lipoproteins and lipid transport proteins that are genetically controlled. Alterations of plasma lipid profiles by genetic manipulation in mice indeed strongly modify resistance to bacterial infections. Recently, the TLR-4 receptor has been identified as the endotoxin receptor, and TLR-4 mutations are the cause of endotoxin resistance in mice. It is probable that such defects also exist in humans, although they must be rare. The capacity of monocytes to produce TNFf varies more than tenfold, and several polymorphisms within the TNFf gene have been associated with increased TNFf production and increased mortality of sepsis. However, these associations most likely result from linkage disequilibrium with other immune response genes on chromosome 6. Polymorphisms within the IL-1g and the IL-1RA genes (located on chromosome 2) are associated with altered protein production rates, and certain haplotypes have been linked to inflammatory disease (no studies in bacterial infectious disease have been published). Mutations in the receptors for IL-12 and IFNn, both critical for clearance of intracellular infectious pathogens, occur in consanguineous populations and are associated with severe recurrent infections with Salmonella species and mycobacteria.¶In conclusion, no human cytokine deficiency syndromes are known, and it remains uncertain whether genetically determined differences in the production rate of pro-inflammatory cytokines alter the outcome of sepsis. In contrast, mutations in the IL-12 and IFNn receptor (and possibly the endotoxin receptor) genes are associated with recurrent bacterial infections, whereas TNFR1 mutations cause fever of unknown origin.     

Évaluation du pouvoir antimicrobien des huiles essentielles de sept plantes médicinales récoltées au Maroc

This study consist to evaluate the antimicrobial effectiveness of certain medicinal plants (Majorana hortensis, Myrtus communis, Mentha rotundifolia, Pelargonium graveolens, Salvia officinalis, Lavandula stoechas, Lavandula angustifolia) judged by the Moroccan traditional medicine have great anti-infective effect. In order to rationalize their use to apply as an alternative to antibiotics cure with the emergence of bacterial multidrug resistance and failure of antibiotic therapy.The essential oils of these plants were tested on seven pathogenic multidrug resistant microbial strains: five bacterial strains Gram (-) (Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Proteus rettgeri, Pseudomonas aeruginosa) one Gram (+) bacteria (Staphylococcus aureus); and Candida albicans as yeast.Very interesting antimicrobial properties of essential oils studied have been noted against the majority of tested germs. This antimicrobial activity on yeast and Gram (+) and Gram (-) multidrug-resistant bacteria, may contribute to fight against infectious diseases and eventually offer the possibility of using pomegranate leaves in food or pharmaceutical industry.     

Plasma levels of danger-associated molecular patterns are associated with immune suppression in trauma patients

Purpose

Danger-associated molecular patterns (DAMPs) released of trauma could contribute to an immune suppressed state that renders patients vulnerable towards nosocomial infections. We investigated DAMP release in trauma patients, starting in the prehospital phase, and assessed its relationship with immune suppression and nosocomial infections.

Methods

Blood was obtained from 166 adult trauma patients at the trauma scene, emergency room (ER), and serially afterwards. Circulating levels of DAMPs and cytokines were determined. Immune suppression was investigated by determination of HLA-DRA gene expression and ex vivo lipopolysaccharide-stimulated cytokine production.

Results

Compared with healthy controls, plasma levels of nuclear DNA (nDNA) and heat shock protein-70 (HSP70) but not mitochondrial DNA were profoundly increased immediately following trauma and remained elevated for 10 days. Plasma cytokines were increased at the ER, and levels of anti-inflammatory IL-10 but not of pro-inflammatory cytokines peaked at this early time-point. HLA-DRA expression was attenuated directly after trauma and did not recover during the follow-up period. Plasma nDNA (r = ?0.24, p = 0.006) and HSP70 (r = ?0.38, p < 0.0001) levels correlated negatively with HLA-DRA expression. Ex vivo cytokine production revealed an anti-inflammatory phenotype already at the trauma scene which persisted in the following days, characterized by attenuated TNF-α and IL-6, and increased IL-10 production. Finally, higher concentrations of nDNA and a further decrease of HLA-DRA expression were associated with infections.

Conclusions

Plasma levels of DAMPs are associated with immune suppression, which is apparent within minutes/hours following trauma. Furthermore, aggravated immune suppression during the initial phase following trauma is associated with increased susceptibility towards infections.

     

Early apoptosis of blood monocytes in the septic host: is it a mechanism of protection in the event of septic shock?

Introduction

Based on the central role of the triggering of monocytes for the initiation of the septic cascade, it was investigated whether apoptosis of blood monocytes in septic patients is connected to their final outcome.

Methods

Blood monocytes were isolated from 90 patients with septic syndrome due to ventilator-associated pneumonia on days 1, 3, 5 and 7 from the initiation of symptoms. Apoptosis was defined after incubation with annexin-V-fluorescein isothiocyanate and propidium iodine and reading by a flow cytometer. The function of first-day monocytes was evaluated from the concentrations of tumour necrosis factor alpha (TNFα) and IL-6 in supernatants of cell cultures after triggering with endotoxins. TNFα, IL-6 and IL-8 were estimated in serum by an enzyme immunoassay.

Results

Mortality rates of patients with apoptosis ≤50% compared with patients with apoptosis >50% were 49.12% and 15.15%, respectively (P < 0.0001). Kaplan-Meier analysis showed a 28-day survival benefit in patients with septic shock and monocyte apoptosis >50% compared with those patients with apoptosis ≤50% (P = 0.0032). Production of IL-6 by monocytes on the first day by patients with apoptosis ≤50% was similar compared with monocytes isolated from healthy controls. Serum concentrations of TNFα were higher in patients with monocyte apoptosis ≤50% and septic shock compared with patients with apoptosis >50% on day 7; similar findings occurred for serum IL-6 on days 1 and 7 and for serum IL-8 on days 1 and 5.

Conclusion

Early apoptosis of monocytes upon presentation of clinical signs of sepsis is connected to a favourable outcome. These findings are of particular importance for the patient with septic shock, where they might constitute a mechanism of pathogenesis.

     

Pathogen colonization of the gastrointestinal microbiome at intensive care unit admission and risk for subsequent death or infection

Purpose

Loss of colonization resistance within the gastrointestinal microbiome facilitates the expansion of pathogens and has been associated with death and infection in select populations. We tested whether gut microbiome features at the time of intensive care unit (ICU) admission predict death or infection.

Methods

This was a prospective cohort study of medical ICU adults. Rectal surveillance swabs were performed at admission, selectively cultured for vancomycin-resistant Enterococcus (VRE), and assessed using 16S rRNA gene sequencing. Patients were followed for 30 days for death or culture-proven bacterial infection.

Results

Of 301 patients, 123 (41%) developed culture-proven infections and 76 (25%) died. Fecal biodiversity (Shannon index) did not differ based on death or infection (p?=?0.49). The presence of specific pathogens at ICU admission was associated with subsequent infection with the same organism for Escherichia coli, Pseudomonas spp., Klebsiella spp., and Clostridium difficile, and VRE at admission was associated with subsequent Enterococcus infection. In a multivariable model adjusting for severity of illness, VRE colonization and Enterococcus domination (≥?30% 16S reads) were both associated with death or all-cause infection (aHR 1.46, 95% CI 1.06–2.00 and aHR 1.47, 95% CI 1.00–2.19, respectively); among patients without VRE colonization, Enterococcus domination was associated with excess risk of death or infection (aHR 2.13, 95% CI 1.06–4.29).

Conclusions

Enterococcus status at ICU admission was associated with risk for death or all-cause infection, and rectal carriage of common ICU pathogens predicted specific infections. The gastrointestinal microbiome may have a role in risk stratification and early diagnosis of ICU infections.

     

Neutrophil extracellular traps (NETs) are increased in the alveolar spaces of patients with ventilator-associated pneumonia

Background

Neutrophils release neutrophil extracellular traps (NETs) in response to invading pathogens. Although NETs play an important role in host defense against microbial pathogens, they have also been shown to play a contributing mechanistic role in pathologic inflammation in the absence of infection. Although a role for NETs in bacterial pneumonia and acute respiratory distress syndrome (ARDS) is emerging, a comprehensive evaluation of NETs in the alveolar space of critically ill patients has yet to be reported. In this study, we evaluated whether markers of NET formation in mechanically ventilated patients are associated with ventilator-associated pneumonia (VAP).

Methods

We collected bronchoalveolar lavage fluid from 100 critically ill patients undergoing bronchoscopy for clinically suspected VAP. Subjects were categorized by the absence or presence of VAP and further stratified by ARDS status. NETs (myeloperoxidase (MPO)-DNA complexes) and the NET-associated markers peroxidase activity and cell-free DNA were analyzed by enzyme-linked immunosorbent assay and colorimetric assays, respectively. Quantitative polymerase chain reaction of nuclear and mitochondrial DNA was used to determine the origin of the extruded DNA. Interleukin (IL)-8 and calprotectin were assayed as measures of alveolar inflammation and neutrophil activation. Correlations between NETs and markers of neutrophil activation were determined using Spearman’s correlation. We tested for associations with VAP and bacterial burden by logistic and linear regression, respectively, using log₁₀-transformed NETs.

Results

MPO-DNA concentrations were highly correlated with other measures of NET formation in the alveolar space, including cell-free DNA and peroxidase activity (r?=?0.95 and r?=?0.87, p?<?0.0001, respectively). Alveolar concentrations of MPO-DNA were higher in subjects with VAP and ARDS compared with those with ARDS alone (p?<?0.0001), and higher MPO-DNA was associated with increased odds of VAP (odds ratio 3.03, p?<?0.0001). In addition, NET concentrations were associated with bacterial burden (p?<?0.0001) and local alveolar inflammation as measured by IL-8 (r?=?0.89, p?<?0.0001).

Conclusions

Alveolar NETs measured by MPO-DNA complex are associated with VAP, and markers of NETosis are associated with local inflammation and bacterial burden in the lung. These results suggest that NETs contribute to inflammatory responses involved in the pathogenesis of VAP.

     

Essais antimicrobiens d’un savon à base d’extrait éthanolique des feuilles de <Emphasis Type="Italic">Morinda morindoides</Emphasis> (Morinda,Rubiaceae) sur la croissance in vitro de germes impliqués dans les infections cutanées

The objective of this study is to develop a soap based on the ethanolic extract of the leaves of Morinda morindoides and to evaluate its antimicrobial activity on the in vitro growth of two bacteria (Staphylococcus aureus and Pseudomonas aeruginosa) and four fungi (Candida albicans, Candida tropicalis, Trichophyton rubrum, and Trichophyton mentagrophytes) involved in skin infections. The ethanolic extract of Morinda morindoides was used as an antimicrobial agent in the manufacture of an anti-infectious soap coded “S2” using a cold process. The antifungal tests of soap with ethanolic extract of Morinda morindoides (S2) and control soap (S0) were carried out using the broth dilution method by incorporation of test soap into Sabouraud agar. The antibacterial parameters of soaps S2 and S0 were determined by incorporation into Mueller-Hinton agar and testing in liquid medium. Soap S2 expressed an effective antimicrobial activity compared to soap S0 with a MIC (Minimum Inhibitory Concentration) of 31.25 mg/ml against tested microbial germs. We conclude that incorporation of 10% of ethanolic extract of Morinda morindoides in the formulation of an anti-infectious soap does not alter its antimicrobial properties. In view of the effectiveness of soap S2 on microbial germs involved in skin infections, its production on an industrial scale will constitute a real hope in the fight against skin diseases, which are very widespread in Côte-d’Ivoire.     

Selecting Patients with Ovarian Cancer for Germline <Emphasis Type="Italic">BRCA</Emphasis> Mutation Testing: Findings from Guidelines and a Systematic Literature Review

Introduction

One of the most significant risk factors for the development of ovarian cancer (OC) is a genetic mutation in BRCA1 (breast cancer gene 1) or BRCA2. Here we describe the impact of previous and current guidance on BRCA testing practices and provide evidence about which characteristics best identify patients with OC and an underlying germline BRCA mutation.

Methods

A search was conducted for guidelines recommending genetic testing to identify constitutional pathogenic mutations in the BRCA genes. In addition, a systematic literature search of studies published in 2003–2015 was performed to assess BRCA mutation frequency in population-based OC patients unselected for patient characteristics (personal history, family history, and Ashkenazi Jewish ethnicity) and to describe the association of patient characteristics with BRCA mutation. Exclusively, studies assessing epithelial OC or invasive epithelial OC with full-gene screening of both BRCA1 and BRCA2 mutations were evaluated.

Results

Of 15 guidelines recommending genetic testing for OC patients, only 5 do not require co-occurrence of specific patient or family characteristics. Twenty-two full publications were identified that assessed germline BRCA mutation frequency in women with OC, utilizing a range of different full mutation detection methods. Germline BRCA mutation prevalence in patients with OC was 5.8–24.8%. Using criteria recommended in guidelines that are yet to be updated, we estimated that 27.5% of all germline BRCA mutations present in patients with OC may be missed because patients do not meet appropriate criteria.

Conclusion

With the availability of BRCA mutation-targeted therapies, identification of patients with OC with germline BRCA mutations has potential therapeutic consequences. For identified gene carriers, predictive testing to allow cancer prevention strategies, including bilateral salpingo-oophorectomy, provides wider benefit to identifying such gene carriers. Updating guidelines will increase the opportunity for targeted treatment among patients and risk reduction in relatives.

Funding

AstraZeneca

     

Frequency of Antimicrobial-Resistant Genes in <Emphasis Type="Italic">Salmonella enteritidis</Emphasis> Isolated from Traditional and Industrial Iranian White Cheeses

Iranian white cheese is one of the most important kinds of cheese produced in large scale with high consumption in the country. This dairy product transmits bacterial pathogens like Salmonella spp. Antibiotic resistant Salmonella are widespread in the world. This study was performed to evaluate the frequency of antimicrobial-resistant Salmonella enteritidis and related genes isolated from traditional and industrial Iranian white cheeses. A total of 200 traditional and industrial Iranian white cheeses were collected within Chaharmahal Va Bakhtiari province (southwest Iran). After culturing on specific media using standard bacterial tests the Salmonella sp. was isolated. For specific detection of S. enteritidis from other Salmonella strains sefA gene was studied. Finally, the antibiotic susceptibility patterns were investigated. Results showed that 17 % of cheese samples were contaminated by Salmonella and 5.5 % of specimens by S. enteritidis. The frequencies of resistance genes including tetA, tetB, tetC, cat3, and floR in isolated S. enteritidis were 36.4, 54.5, 81.8, 54.5, and 36.4 %, respectively. All isolated S. enteritidis were susceptible to ciprofloxacin, cefotaxime, and ceftazidime (100 %). In addition, most of them were resistance to chloramphenicol (64 %) and susceptible to gentamicin (98 %). The Salmonella contamination was more frequent in traditional Iranian white cheeses (11.5 %) as compared to industrial (5.5 %) samples (p < 0.05). As compared to industrial samples, high level of resistant genes in Salmonella enteritidis isolated from traditional Iranian white cheeses were observed (p < 0.05). Therefore, traditional Iranian white cheeses are important source of Salmonella contamination in the country hence examination of dairy products for the presence of this pathogen is important.     

Beta-lactamases: Current situation and clinical importance

Production of beta-lactamases is the most important means of bacterial resistance to beta-lactam antibiotics. The traditional, plasmid-mediated beta-lactamases were initially confined to enterobacteriaceae but have now spread to other genera and species includingPseudomonas aeruginosa, Haemophilus influenzae, andNeisseria gonorrhoeae. Extended-spectrum plasmid-mediated beta-lactamases have been identified inEnterobacteriaceae, particularlyKlebsiella spp. andEscherichia coli. They are capable of hydrolyzing second- and third-generation cephalosporins and older beta-lactams. Chromosomally mediated beta-lactamases may be produced constitutively or induced by the presence of a beta-lactam. Mutation within the bacterial genome may lead to constitutive enzyme hyperproduction. Strains that produce these enzymes are resistant to practically all beta-lactams, with the exception of carbapenems. The widespread occurrence of antibiotic resistance dictates that therapies be judiciously chosen with attention to the resistance patterns of the causative organisms.     

Relationship of fluconazole prophylaxis with fungal microbiology in hospitalized intra-abdominal surgery patients: a descriptive cohort study

Introduction

Historically, Candida albicans has represented the most common cause of candidemia. However, the proportion of bloodstream infections due to non-albicans Candida species has increased. Because of the risk for candidemia in intra-abdominal surgical patients, some experts advocate the use of fluconazole prophylaxis. The impact of this practice on the distribution of Candida species isolated in breakthrough fungal infections in this population is unknown. We examined the association of fluconazole prophylaxis with the distribution of Candida species in intra-abdominal surgery patients.

Methods

We retrospectively identified cases with a positive blood culture (BCx) for Candida among hospitalized adult intra-abdominal surgery patients between July 2005 and October 2012. Distribution of Candida species isolated represented our primary endpoint. Qualifying surgical cases were determined based on a review of discharge International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. Patients receiving low-dose fluconazole prior to the positive BCx with a known indication for prophylaxis including neutropenia, ICU exposure or history of organ transplantation were classified as prophylaxis. Appropriateness of fungal treatment was determined by the timing and selection of antifungal agent based on fungal isolate.

Results

Among 10,839 intra-abdominal surgery patients, 227 had candidemia. The most common Candida species isolated was C. albicans (n = 90, 39.6%) followed by C. glabrata (n = 81, 35.7%) and C. parapsilosis (n = 38, 16.7%). Non-albicans Candida accounted for 57.7% of isolates among the 194 non-prophylaxis patients and 75.8% among the 33 prophylaxis patients (P = 0.001). C. glabrata, the most common non-C. albicans species, was more prevalent than C. albicans in persons given prophylaxis, but not in those without prophylaxis. A total of 63% of those with candidemia were treated inappropriately based on the timing and selection of antifungal administration.

Conclusions

Selection pressure from fluconazole prophylaxis in at-risk surgical patients may be associated with a drift toward fluconazole-resistant species in subsequent candidemia. Tools are needed to guide appropriate treatment through the prompt recognition and characterization of candidemia.

     

Antibacterial Activity of Extract of Endophytic Fungi of <Emphasis Type="Italic">Gymnema sylvestre</Emphasis>

Endophytic fungi were isolated from Gymnema sylvestre, a known medicinal plant for hypoglycemic activity. Isolated endophytes were screened for their antibacterial activity against an array of pathogenic bacteria. The systemic study was made on endophytic fungi of medicinal plant, G. sylvestre growing in different natural habitats of India. A total of 25 fungal isolates were recovered from different parts of G. sylvestre and they were grouped in 11 fungal genera. Potato dextrose agar medium yielded the highest number of isolates with the greatest species richness. The fungi were identified as Fusarium sp., Alternaria sp., Phomopsis sp., Pestalotia sp., Xylaria sp., Phyllosticta sp., Gleomastix sp., Acrimonium sp., Aspergillus sp., Cladosporium sp. and Scytalidium sp. The secret of this medicinal plant was revealed by the evaluation of the extract of its endophytic fungi having antibacterial activity. Traditionally this plant is being used since long in diabetic treatment, however it is also effective against the infection. The extracts of five fungal isolates among 25 isolates were found effective inhibitors against human pathogenic bacterial strains Escherichia coli (ATCC 25922) a gram negative and Staphylococcus aureus (ATCC 25323) a gram positive bacteria.     

Emergence of <Emphasis Type="Italic">Moraxella bovoculi</Emphasis> Associated with Keratoconjunctivitis in an Organized Dairy Farm of India

An investigation was carried out in an organized dairy farm of Tamil Nadu State, India where cattle were reported to have eye infection. Preliminary clinical intervention revealed that the animals had infectious bovine keratoconjunctivitis (IBK). Isolation and identification of pathogen from eye swab revealed the presence of Moraxella spp. On further molecular characterization by Polymerase chain reaction (PCR) suggested that the isolate as Moraxella bovoculi. PCR followed by sequencing was carried and the results showed that the isolate was M. bovoculi and the sequence was submitted in the GenBank with the sequence id. KX121047. Animals were treated with antibiotics as per the results from antibiotic sensitivity test and treatment yielded good results as the animals responded to treatment. This report is the first of its kind from India as there was no previous report regarding M. bovoculi from the country. Further insights into the bacterial genome can aid in identification of the genes or regions involved in pathogenesis of IBK and also to carve out the prevention and control strategies of IBK.     

Prise en charge des infections à <Emphasis Type="Italic">Streptococcus pneumoniae</Emphasis> : ce qui a changé en 15 ans

Streptococcus pneumoniae is a pathogen associated with a high prevalence and life-threatening illness in some patients. In the early 2000s, emergence of penicillinnonsusceptible S. pneumoniae reaching 50% of pneumococcal isolates, publication of national and international guidelines, development of new antimicrobial drugs and pneumococcal conjugate vaccine suggested new epidemiological and therapeutic perspectives. Today, S. pneumoniae is the most common bacterial cause of community-acquired pneumonia and meningitis even if invasive pneumococcal disease has declined in all age groups with the introduction of pneumococcal conjugate vaccine. Antibiotic resistance has decreased with a prevalence of penicillin-nonsusceptible S. pneumoniae reaching 20% of pneumococcal isolates. The optimal antibiotic management of patients with pneumococcal meningitis includes a third-generation cephalosporin alone. Combination therapy associating a betalactamin with a macrolide could be proposed in patients with severe pneumococcal pneumonia. Adjunctive corticosteroids are recommended with antimicrobial therapy in patients with pneumococcal meningitis and can help to decrease treatment failure in patients with severe community-acquired pneumonia. Pneumococcal infections continue to cause significant mortality despite adequate and rapid delivery of antimicrobial therapy. Recently, cardiac complications related to pneumococcal toxicity have been described. A better understanding of the virulence factors of S. pneumoniae and their role in the pathogenesis of severe pneumococcal disease could allow to decrease mortality.     

Identification and Expression Analysis of Thyroid Stimulating Hormone Receptor (TSHR) in Fish Gonads Following LHRH Treatment

Thyroid hormones (THs) play an important role in many physiological functions both in mammalian and non-mammalian vertebrates. The effect of THs is mediated by thyroid hormone receptors, which are members of nuclear hormone receptor super family. cDNA sequence of 816 bp mRNA of Thyroid stimulating hormone receptor (TSHR) was cloned from Clarias batrachus, which encoded a peptide of 272 amino acids. The deduced amino acid sequence showed high similarity to Clarias gariepinus and Ictalurus punctatus. Phylogenetic analysis of C. batrachus deduced amino acid sequence showed more similarity with C. gariepinus and I. punctatus. The qPCR result displayed that TSHR mRNA was highly expressed in brain, testis and ovary. mRNA expression level of TSHR was analysed after administration of three different dosages of sLHRH viz 0.02, 0.03 and 0.050 μg/g body weights respectively at different time points. The TSHR mRNA expression was upregulated both with respect to different dosages (maximum in 0.05 μg/g) and time intervals (maximum after 6 h) in all treatments. The higher expression of TSHR mRNA in gonads and upregulation of THSR mRNA expression level after sLHRH administration clearly shows the positive relation between Thyroid hormones and reproduction in fishes. This is first report of LHRH hormone effect on TSHR at molecular level in fish.     

Rate of bacterial eradication by ophthalmic solutions of fourth-generation fluoroquinolones

Introduction

Antibacterial activity of ophthalmic fourth-generation fluoroquinolones has traditionally been evaluated by comparing only their active ingredients, gatifloxacin and moxifloxacin. However, ophthalmic formulations of fourth-generation fluoroquinolones differ in terms of the inclusion of preservatives. While gatifloxacin ophthalmic solution 0.3% (Zymar®; Allergan, Inc., Irvine, CA, USA) contains 0.005% benzalkonium chloride (BAK), moxifloxacin ophthalmic solution 0.5% (Vigamox®; Alcon Laboratories, Inc., Fort Worth, TX, USA) is preservative-free. Recent studies have demonstrated that the presence of BAK dramatically affects the antibacterial activity of the ophthalmic formulation of gatifloxacin. This study was designed to compare the kill rates of ophthalmic solutions of fourth-generation fluoroquinolones against isolates of common ocular bacterial pathogens.

Methods

Approximately 5.6 log₁₀ colony-forming units (CFU)/mL of Haemophilus influenzae (n=1), Streptococcus pneumoniae (n=1), Staphylococcus aureus (n=2), methicillin-resistant Staphylococcus aureus (MRSA) (n=4), methicillinresistant Staphylococcus epidermidis (MRSE) (n=4), and fluoroquinolone-resistant S. epidermidis (n=1) were incubated with ophthalmic solutions of either gatifloxacin or moxifloxacin. Viable bacteria were quantified at specific time points up to 60 minutes.

Results

Gatifloxacin 0.3% completely eradicated H. influenzae and Strep. pneumoniae in 5 minutes, one of two S. aureus isolates in 15 minutes, and the other S. aureus isolate in 60 minutes. Gatifloxacin 0.3% completely killed all MRSA, MRSE, and fluoroquinolone-resistant S. epidermidis isolates in 15 minutes. Moxifloxacin 0.5% completely eradicated Strep. pneumoniae and one of four MRSA isolates in 60 minutes. All other isolates incubated with moxifloxacin 0.5% retained viable bacteria ranging from 1.8 to 4.4 log₁₀ CFU/mL.

Conclusions

The ophthalmic solution of gatifloxacin 0.3% eradicated bacteria that frequently cause postoperative ocular infections substantially faster than did the ophthalmic solution of moxifloxacin 0.5%.

     

Subtypes of pediatric acute respiratory distress syndrome have different predictors of mortality

Purpose

Acute respiratory distress syndrome (ARDS) is heterogeneous in etiology, which may affect outcomes. Stratification into biologically-defined subtypes may reduce heterogeneity. However, it is unknown whether pediatric ARDS has clinically relevant subtypes. We aimed to determine whether clinical characteristics and predictors of mortality differed between direct and indirect ARDS, and separately between infectious and non-infectious ARDS.

Methods

This was a single center, prospective cohort study of 544 children with ARDS (Berlin) between July 2011 and June 2017, stratified into direct versus indirect ARDS, and separately into infectious versus non-infectious ARDS. Multiple logistic regression was used to test for predictors of mortality in the entire cohort, and separately within subtypes. Effect modification by subtype was assessed using interaction tests.

Results

Direct ARDS had lower severity of illness (p?<?0.001) but worse oxygenation (p?<?0.001), relative to indirect. Predictors of mortality were similar for direct and indirect ARDS. When comparing infectious and non-infectious ARDS, infectious ARDS had lower severity of illness (p?<?0.001), worse oxygenation (p?=?0.014), and lower mortality (p?=?0.013). In multivariable analysis, immunocompromised status demonstrated effect modification between infectious and non-infectious ARDS (p?=?0.005 for interaction), with no association with mortality in non-infectious ARDS.

Conclusions

In children, direct and indirect ARDS have distinct clinical characteristics, but similar outcomes and similar predictors of mortality. In contrast, infectious and non-infectious ARDS demonstrate heterogeneity of clinical characteristics, mortality, and predictors of mortality, with traditional predictors of ARDS mortality only applicable to infectious ARDS.

     

Phenotypic and Molecular Characterization of Alleles of Grain Quality Genes in Bread Wheat Genotypes

Grain quality is an important determinant of market value of wheat. Identification of the genes that influence grain quality traits and estimation of effects of alleles of these genes can improve the effectiveness of wheat breeding. Sixty-four bread wheat cultivars from six different agro-climatic zones of India and eleven Australian cultivars were analyzed for the prevalence of Puroindoline (Pin) hardness mutations and Storage Protein Activator (SPA) alleles for detecting allelic diversity among these varieties. Most of the Australian genotypes had soft or semi hard textured grains and amplified both Pina and Pinb genes. In Indian genotypes, most of the genotypes had hard grain texture and the null mutation of Pina and the wild type Pinb allele (Pina-D1b/Pinb-D1a) was the most frequent combination in the Indian wheat germplasm. Predominance of Spa gene was observed in both Australian and Indian genotypes and all these genotypes recorded high grain protein content as compared to genotypes which are having null allele for SpaB gene. This study can provide useful information for the improvement of wheat quality in selecting parental lines for crossing to maximize diversity at these loci and enhance the effectiveness of molecular marker assisted crop breeding.     

Characterization and Mosquitocidal Potential of the Soil Bacteria <Emphasis Type="Italic">Aneurinibacillus aneurinilyticus</Emphasis> Isolated from Burdwan,West Bengal,India

Aedes aegypti, Anopheles subpictus and Culex quinquefasciatus are the principal vector mosquitoes globally, especially in tropical and subtropical countries. It is very essential to control the mosquito population to prevent mosquito-borne disease transmission. The major goal of the present study was to isolate an alternative for the microbial mosquito control agents like Bacillus thuringiensis and Bacillus sphaericus. The spore forming soil bacteria isolated from Burdwan, West Bengal, India were assessed for mosquitocidal potential. One potent mosquitocidal isolate was characterized by phenotypic, biochemical and 16S rDNA sequence (GU244410) analysis. The isolate was identified as Aneurinibacillus aneurinilyticus. Five ml bacterial suspension of A. aneurinilyticus (22 × 10⁹ colony forming unit/milliliter)/100 ml water resulted in 34, 59.6 and 100 % mortality of Ae. aegypti, Cx. quinquefasciatus and An. subpictus larvae respectively within 72 h, whereas, 10 ml suspension having same concentration showed 95 and 97 % death of Ae. aegypti and Cx. quinquefasciatus larvae respectively within the same time period.