Genotyping Oral Commensal Bacteria to Predict Social Contact and Structure

Social network structure is a fundamental determinant of human health, from infectious to chronic diseases. However, quantitative and unbiased approaches to measuring social network structure are lacking. We hypothesized that genetic relatedness of oral commensal bacteria could be used to infer social contact between humans, just as genetic relatedness of pathogens can be used to determine transmission chains of pathogens. We used a traditional, questionnaire survey-based method to characterize the contact network of the School of Public Health at a large research university. We then collected saliva from a subset of individuals to analyze their oral microflora using a modified deep sequencing multilocus sequence typing (MLST) procedure. We examined micro-evolutionary changes in the S. viridans group to uncover transmission patterns reflecting social network structure. We amplified seven housekeeping gene loci from the Streptococcus viridans group, a group of ubiquitous commensal bacteria, and sequenced the PCR products using next-generation sequencing. By comparing the generated S. viridans reads between pairs of individuals, we reconstructed the social network of the sampled individuals and compared it to the network derived from the questionnaire survey-based method. The genetic relatedness significantly (p-value < 0.001) correlated with social distance in the questionnaire-based network, and the reconstructed network closely matched the network derived from the questionnaire survey-based method. Oral commensal bacterial are thus likely transmitted through routine physical contact or shared environment. Their genetic relatedness can be used to represent a combination of social contact and shared physical space, therefore reconstructing networks of contact. This study provides the first step in developing a method to measure direct social contact based on commensal organism genotyping, potentially capable of unmasking hidden social networks that contribute to pathogen transmission.

[Update in Infectious Diseases 2016]

Antimicrobial resistance increases it health, social and economic impact. in all areas (state, regional and local), initiatives to try to contain the problem of resistance arise. In the update of this year 2016, we study microbiological, epidemiological and clinical aspects of multi-resistant bacteria, as well as resources for therapeutic approach, from ancient to modern drugs from therapeutic combinations to optimization Stewardship programs. In the case of fungal infection, we analyze clinical scenarios with different species in yeast or new clinical settings in filamentous fungi. Taking paediatric population, homologies and differences with adults in invasive fungal infection were compared. Finally in the field of parasitology, treatment of severe malaria imported or that resistant to antimalarial drugs were reviewed.

Tordylium persicum Boiss. & Hausskn extract: A possible alternative for treatment of pediatric infectious diseases

Antimicrobial herbal compounds are one of the important medical resources, and in order to help alleviate the spread of the pediatric infectious diseases, identification of additional bioactive phytochemicals and herbal extracts will be practical in treating illnesses. In the present work, antimicrobial activities various extracts of Tordylium persicum Boiss. & Hausskn aerial parts were determined against five Gram-positive bacteria, five Gram-negative bacteria, two fungi, and Echinococcus granulosus. Antimicrobial activities were assayed using both disk diffusion and microbroth dilution methods. Scolicidal activity was assayed by the Smyth and Barrett method. Also total phenol and total flavonoid contents for plant extracts were assayed. Results showed that the methanolic extract was more effective on all microbes. The results showed that Streptococcus pyogenes was the most susceptible to the methanolic extract (MIC = 25.9 ± 0.0 µg/mL), while Proteus vulgaris was the most resistant strain (MIC = 295.3 ± 0.0 µg/mL) among all bacteria evaluated. The extracts showed significant activity versus E. granulosus (P < 0.5) with dose-dependent inhibitions of the protoscolices. The high concentration of total polyphenolics (294.5 ± 0.1 GAE/g DW) and flavonoids (105.7 ± 0.3 mg CE/g DW) may be responsible for these activities. Our study is first evaluation on antimicrobial and scolicidal activities of T. persicum. Due to the appearance of antibiotic-resistance, ourstudy suggested that methanol extracts of this plant are appropriate candidate for traditional curative uses and it can be utilized in the pediatric infectious disease therapy, especially pediatric infectious disease.

Revaccination with Live Attenuated Vaccines Confer Additional Beneficial Nonspecific Effects on Overall Survival: A Review

BACKGROUND

Live vaccines against measles (MV), tuberculosis (BCG), polio (OPV) and smallpox reduce mortality more than explained by target-disease prevention. The beneficial nonspecific effects (NSEs) of MV are strongest when MV is given in presence of maternal antibodies. We therefore hypothesised that revaccination in presence of prior immunity enhances beneficial NSEs.

METHODS

Literature search for studies of revaccination and mortality.

FINDINGS

In two randomised trials (RCTs), two doses versus one dose of MV reduced all-cause mortality by 63% (95% CI: 23-83%) from 9 to 18months of age. In a quasi-experimental study two doses before and after 9months compared with one dose of MV after 9months of age reduced mortality by 59% (25-81%). BCG-revaccination significantly enhanced BCG's effect against overall child mortality in two RCTs. In a natural experiment study of OPV campaigns over a 13-year-period in Guinea-Bissau, each additional dose of OPV was associated with a 13% (4-21%) reduction in mortality rate. The beneficial NSEs of smallpox vaccination for survival increased significantly with the number of smallpox vaccination scars.

INTERPRETATION

Revaccination with live vaccines led to substantial reductions in overall mortality. These findings challenge current understanding of vaccines and may explain the beneficial effects of campaigns with live vaccines.

Preventing Data Ambiguity in Infectious Diseases with Four-Dimensional and Personalized Evaluations

Background

Diagnostic errors can occur, in infectious diseases, when anti-microbial immune responses involve several temporal scales. When responses span from nanosecond to week and larger temporal scales, any pre-selected temporal scale is likely to miss some (faster or slower) responses. Hoping to prevent diagnostic errors, a pilot study was conducted to evaluate a four-dimensional (4D) method that captures the complexity and dynamics of infectious diseases.

Methods

Leukocyte-microbial-temporal data were explored in canine and human (bacterial and/or viral) infections, with: (i) a non-structured approach, which measures leukocytes or microbes in isolation; and (ii) a structured method that assesses numerous combinations of interacting variables. Four alternatives of the structured method were tested: (i) a noise-reduction oriented version, which generates a single (one data point-wide) line of observations; (ii) a version that measures complex, three-dimensional (3D) data interactions; (iii) a non-numerical version that displays temporal data directionality (arrows that connect pairs of consecutive observations); and (iv) a full 4D (single line-, complexity-, directionality-based) version.

Results

In all studies, the non-structured approach revealed non-interpretable (ambiguous) data: observations numerically similar expressed different biological conditions, such as recovery and lack of recovery from infections. Ambiguity was also found when the data were structured as single lines. In contrast, two or more data subsets were distinguished and ambiguity was avoided when the data were structured as complex, 3D, single lines and, in addition, temporal data directionality was determined. The 4D method detected, even within one day, changes in immune profiles that occurred after antibiotics were prescribed.

Conclusions

Infectious disease data may be ambiguous. Four-dimensional methods may prevent ambiguity, providing earlier, in vivo, dynamic, complex, and personalized information that facilitates both diagnostics and selection or evaluation of anti-microbial therapies.

[Infectious diseases in the genomic era]

Next generation sequencing (NGS) technologies have arrived, changing research and infectious disease research into a new era, the "genomic era". Currently, the developed world is introducing NGS in a number of applications, including clinical diagnostics, epidemiology, and microbiology. In developing countries NGS is being progressively introduced. Technologies currently available allow to sequence the whole genome of bacterial and viral strains for an approximate cost of $100 USD, which is highly cost savings compared to old-technologies for genome sequencing. Here we review recent publication of whole genome sequencing used for, (i) tracking of foodborne outbreaks, with emphasis in Salmonella and Listeria monocytogenes, (ii) building genomic databases for Governments, (iii) investigating nosocomial infections, and (iv) clinical diagnosis. The genomic era is here to stay and researchers should use these "massive databases" generated by this technology to decrease infectious diseases and thus improve health of humans and animals.

High Prevalence of Infectious Diseases and Drug-Resistant Microorganisms in Asylum Seekers Admitted to Hospital; No Carbapenemase Producing Enterobacteriaceae until September 2015

Introduction

The current refugee crisis emphasizes the need for information on infectious diseases and resistant microorganisms in asylum seekers with possible consequences for public health and infection control.

Methods

We collected data from asylum seekers admitted to our university hospital or who presented at the Emergency Department (n = 273). We collected general and demographic characteristics including country of origin, the reason of presentation, and the screening results of multi-drug resistant organisms.

Results

67% of the patients were male with a median age of the study group of 24 years (IQR 15–33); 48% of the patients had an infectious disease—predominantly malaria with P. vivax or tuberculosis. Patients also reported with diseases which are less common—e.g. leishmaniasis, or even conditions rarely diagnosed in Europe—e.g. louse borne relapsing fever. A carriage rate of 31% for multi-drug resistant microorganisms (MDRO) was observed, with ESBL-expressing E.coli (n = 20) being the most common MDRO. No carriage of Carbapenemase Producing Enterobacteriaceae was found.

Conclusion

The current refugee crisis in Europe challenges hospitals to quickly identify and respond to communicable diseases and the carriage of MDRO. A rapid response is necessary to optimize the treatment of infectious diseases amongst asylum seekers to maximize infection control.

[PROCUREMENT OF SANITARY AND EPIDEMIOLOGICAL WELFARE IN THE REGION OF-CITY-RESORT SOCHI FOR DANGEROUS AND NATURAL-FOCI INFECTIOUS DIS- EASES IN 2015]

AIM

Analysis ofresults of epidemiologic monitoring especially dangerous, natural-foci and other infectious diseases, asill as epizootologic activity of natural foci of infection on,the terri- tory, of city-resort Sochi.

MATERIALS AND METHODS

Laboratory studies of 820. samples by PCR; im- mune- and bacteriologic methods were carried out, among those 344 - clinical material, 12 - water from open bodies and 321 - field material. Molecular-genetic identification of-143 strains of Vibrio-cholerae, isolated from open water bodies of city-resort Sochi, was-carried out,.

RESULTS

Circulation of causative agents of Q fever, tularemia and hemorrhagic fever with renal syndrome of Dobrava-Adler genotypes was established, -as well as rickettsia of tick spotted fever group Predomination of rotaviruses (70.9%) was detected during study of samples of clinical material in etiologic structure of sporadically emerging acute intestine infections. Relatively high temperature values of river water during summer months (from 18, to 30 C), exit of sulfide mineral waters into the riverbed, that create-alkaline medium, seasonal reduction of river debit and speed of water current facilitated sustenance of contamination of water of Agura river by V.cholerae.

CONCLUSION

Activity of natural foci of the infectious disease and contamination of Agura iver by V.cholerae Ο1, (atoxigenic) gives evidence on the necessity of constant control of epidemiologic situation by dangerous and natural-foci infectious diseases on the territory of city-resort Sochi, as well as study regional features, of their causative agents, including using genetic methods.

Summary of National Surveillance Data on Vaccine Preventable Diseases in Australia, 2008-2011

This summary report on vaccine preventable diseases in Australia brings together the 3 most important national sources of routinely collected data on vaccine preventable diseases (notifications, hospitalisations and deaths) for all age groups for the period January 2008 to December 2011. The general trend towards improved control of disease is evident, particularly in the childhood years. Detailed results are available in 16 individual chapters. Although these data have limitations, which are discussed in detail in the body of the report, some clear trends are evident. Compared with the previous review period (2005-2007), there are continuing declines in the overall disease burden, driven by improving control of mumps, rubella, hepatitis B and meningococcal disease. There is an ongoing absence of disease due to polio and a continuing low incidence of tetanus. There have been continuing declines in the incidence of hepatitis A and B. However, there were 4 notified cases of diphtheria in 2011; prior to these reports there had been no notified diphtheria cases since 2001. Influenza and pertussis notifications have increased, whereas notifications and hospitalisations for mumps have remained stable and for meningococcal disease have declined. Influenza, pertussis and pneumococcal disease continue to contribute the greatest burden of serious disease.

The Typhoid Toxin Promotes Host Survival and the Establishment of a Persistent Asymptomatic Infection

Bacterial genotoxins, produced by several Gram-negative bacteria, induce DNA damage in the target cells. While the responses induced in the host cells have been extensively studied in vitro, the role of these effectors during the course of infection remains poorly characterized. To address this issue, we assessed the effects of the Salmonella enterica genotoxin, known as typhoid toxin, in in vivo models of murine infection. Immunocompetent mice were infected with isogenic S. enterica, serovar Typhimurium (S. Typhimurium) strains, encoding either a functional or an inactive typhoid toxin. The presence of the genotoxic subunit was detected 10 days post-infection in the liver of infected mice. Unexpectedly, its expression promoted the survival of the host, and was associated with a significant reduction of severe enteritis in the early phases of infection. Immunohistochemical and transcriptomic analysis confirmed the toxin-mediated suppression of the intestinal inflammatory response. The presence of a functional typhoid toxin further induced an increased frequency of asymptomatic carriers. Our data indicate that the typhoid toxin DNA damaging activity increases host survival and favours long-term colonization, highlighting a complex cross-talk between infection, DNA damage response and host immune response. These findings may contribute to understand why such effectors have been evolutionary conserved and horizontally transferred among Gram-negative bacteria.

Bloodstream infections in the Intensive Care Unit

Bloodstream infections (BSIs) represent a common complication among critically ill patients and a leading cause of morbidity and mortality. The prompt initiation of an effective antibiotic therapy is necessary in order to reduce mortality and to improve clinical outcomes. However, the choice of the empiric antibiotic regimen is often challenging, due to the worldwide spread of multi-drug resistant (MDR) organisms with reduced susceptibility to the available broad-spectrum antimicrobials. New therapeutic strategies are 5 to improve the effectiveness of antibiotic treatment while minimizing the risk of resistance selection.

Epigenetic impact of infection on carcinogenesis: mechanisms and applications

Viral and bacterial infections are involved in the development of human cancers, such as liver, nasopharyngeal, cervical, head and neck, and gastric cancers. Aberrant DNA methylation is frequently present in these cancers, and some of the aberrantly methylated genes are causally involved in cancer development and progression. Notably, aberrant DNA methylation can be present even in non-cancerous or precancerous tissues, and its levels correlate with the risk of cancer development, producing a so-called 'epigenetic field for cancerization'. Mechanistically, most viral or bacterial infections induce DNA methylation indirectly via chronic inflammation, but recent studies have indicated that some viruses have direct effects on the epigenetic machinery of host cells. From a translational viewpoint, a recent multicenter prospective cohort study demonstrated that assessment of the extent of alterations in DNA methylation in non-cancerous tissues can be used to predict cancer risk. Furthermore, suppression of aberrant DNA methylation was shown to be a useful strategy for cancer prevention in an animal model. Here, we review the involvement of aberrant DNA methylation in various types of infection-associated cancers, along with individual induction mechanisms, and we discuss the application of these findings for cancer prevention, diagnosis, and therapy.

Electrochemical magnetic microbeads-based biosensor for point-of-care serodiagnosis of infectious diseases

Access to appropriate diagnostic tools is an essential component in the evaluation and improvement of global health. Additionally, timely detection of infectious agents is critical in early diagnosis and treatment of infectious diseases. Conventional pathogen detection methods such as culturing, enzyme linked immunosorbent assay (ELISA) or polymerase chain reaction (PCR) require long assay times, and complex and expensive instruments making them not adaptable to point-of-care (PoC) needs at resource-constrained places and primary care settings. Therefore, there is an unmet need to develop portable, simple, rapid, and accurate methods for PoC detection of infections. Here, we present the development and validation of a portable, robust and inexpensive electrochemical magnetic microbeads-based biosensor (EMBIA) platform for PoC serodiagnosis of infectious diseases caused by different types of microorganisms (parasitic protozoa, bacteria and viruses). We demonstrate the potential use of the EMBIA platform for in situ diagnosis of human (Chagas disease and human brucellosis) and animal (bovine brucellosis and foot-and-mouth disease) infections clearly differentiating infected from non-infected individuals or animals. For Chagas disease, a more extensive validation of the test was performed showing that the EMBIA platform displayed an excellent diagnostic performance almost indistinguishable, in terms of specificity and sensitivity, from a fluorescent immunomagnetic assay and the conventional ELISA using the same combination of antigens. This platform technology could potentially be applicable to diagnose other infectious and non-infectious diseases as well as detection and/or quantification of biomarkers at the POC and primary care settings.

Structural and Functional Aspects of Class A Carbapenemases

The fight against infectious diseases is probably one of the greatest public health challenges faced by our society, especially with the emergence of carbapenem-resistant gram-negatives that are in some cases pan-drug resistant. Currently,β-lactamase-mediated resistance does not spare even the newest and most powerful β-lactams (carbapenems), whose activity is challenged by carbapenemases. The worldwide dissemination of carbapenemases in gram-negative organisms threatens to take medicine back into the pre-antibiotic era since the mortality associated with infections caused by these "superbugs" is very high, due to limited treatment options. Clinically-relevant carbapenemases belong either to metallo-β- lactamases (MBLs) of Ambler class B or to serine-β-lactamases (SBLs) of Ambler class A and D enzymes. Class A carbapenemases may be chromosomally-encoded (SME, NmcA, SFC-1, BIC-1, PenA, FPH-1, SHV-38), plasmid-encoded (KPC, GES, FRI-1) or both (IMI). The plasmid-encoded enzymes are often associated with mobile elements responsible for their mobilization. These enzymes, even though weakly related in terms of sequence identities, share structural features and a common mechanism of action. They variably hydrolyse penicillins, cephalosporins, monobactams, carbapenems, and are inhibited by clavulanate and tazobactam. Three-dimensional structures of class A carbapenemases, in the apo form or in complex with substrates/inhibitors, together with site-directed mutagenesis studies, provide essential input for identifying the structural factors and subtle conformational changes that influence the hydrolytic profile and inhibition of these enzymes. Overall, these data represent the building blocks for understanding the structure-function relationships that define the phenotypes of class A carbapenemases and can guide the design of new molecules of therapeutic interest.

Impact of climate change on human infectious diseases: Empirical evidence and human adaptation

Climate change refers to long-term shifts in weather conditions and patterns of extreme weather events. It may lead to changes in health threat to human beings, multiplying existing health problems. This review examines the scientific evidences on the impact of climate change on human infectious diseases. It identifies research progress and gaps on how human society may respond to, adapt to, and prepare for the related changes. Based on a survey of related publications between 1990 and 2015, the terms used for literature selection reflect three aspects--the components of infectious diseases, climate variables, and selected infectious diseases. Humans' vulnerability to the potential health impacts by climate change is evident in literature. As an active agent, human beings may control the related health effects that may be effectively controlled through adopting proactive measures, including better understanding of the climate change patterns and of the compound disease-specific health effects, and effective allocation of technologies and resources to promote healthy lifestyles and public awareness. The following adaptation measures are recommended: 1) to go beyond empirical observations of the association between climate change and infectious diseases and develop more scientific explanations, 2) to improve the prediction of spatial-temporal process of climate change and the associated shifts in infectious diseases at various spatial and temporal scales, and 3) to establish locally effective early warning systems for the health effects of predicated climate change.

The threats for human health induced by food pests of Plodia interpunctella as reservoirs of infectious microbiota

INTRODUCTION

World-wide distributed pests of Plodia interpunctella occur with increasing frequency also in Poland, in areas where food is prepared and stored, in dwellings, buildings of public use, hospitals. Larvae damage various products causing economic losses. There were no data about microbiota transmission by pests. The aim of our systematic studies firstly conducted in Poland was to explain a role of pests as reservoirs of microbiota and assess health risk induced by them in human environments.

MATERIAL AND METHODS

300 adults and 200 larvae, collected in households and health facilities by traps and directly from products, were examined by light microscopy, in vitro cultivations, molecular techniques; the susceptibility /resistance of microbiota to chemicals was also assessed.

RESULTS

Gram+ bacteriae of genera Enterococcus, Micrococcus, Bacillus, Gram-: Klebsiella, Escherichia, mold fungi: Aspergillus, Penicillium and yeast-like fungi were identified, including strains potentially pathogenic for humans.

CONCLUSIONS

In the European Union countries, the food circulation is audited by the law; chemicals are applied to eliminate P.interpunctella pests causing economic losses. Our successive studies showed that pyralids may generate health problems as food pests and as reservoirs of microbiota. Sources of the pathogenic, drug-resistant strains revealed by us, not identified earlier, may be particularly dangerous for elder persons, with weakened immune system, persons from groups of high risk of infections. The increased awareness of the problem is necessary for more efficacy of preventive measures. A monitoring of consequences of the health risk induced by the pests may supply data useful for adequate practical approach.

Genomic perspectives on the evolution and spread of bacterial pathogens

Since the first complete sequencing of a free-living organism, Haemophilus influenzae, genomics has been used to probe both the biology of bacterial pathogens and their evolution. Single-genome approaches provided information on the repertoire of virulence determinants and host-interaction factors, and, along with comparative analyses, allowed the proposal of hypotheses to explain the evolution of many of these traits. These analyses suggested many bacterial pathogens to be of relatively recent origin and identified genome degradation as a key aspect of host adaptation. The advent of very-high-throughput sequencing has allowed for detailed phylogenetic analysis of many important pathogens, revealing patterns of global and local spread, and recent evolution in response to pressure from therapeutics and the human immune system. Such analyses have shown that bacteria can evolve and transmit very rapidly, with emerging clones showing adaptation and global spread over years or decades. The resolution achieved with whole-genome sequencing has shown considerable benefits in clinical microbiology, enabling accurate outbreak tracking within hospitals and across continents. Continued large-scale sequencing promises many further insights into genetic determinants of drug resistance, virulence and transmission in bacterial pathogens.

EPIMIC: A Simple Homemade Computer Program for Real-Time EPIdemiological Surveillance and Alert Based on MICrobiological Data

BACKGROUND AND AIMS

Infectious diseases (IDs) are major causes of morbidity and mortality and their surveillance is critical. In 2002, we implemented a simple and versatile homemade tool, named EPIMIC, for the real-time systematic automated surveillance of IDs at Marseille university hospitals, based on the data from our clinical microbiology laboratory, including clinical samples, tests and diagnoses.

METHODS

This tool was specifically designed to detect abnormal events as IDs are rarely predicted and modeled. EPIMIC operates using Microsoft Excel software and requires no particular computer skills or resources. An abnormal event corresponds to an increase above, or a decrease below threshold values calculated based on the mean of historical data plus or minus 2 standard deviations, respectively.

RESULTS

Between November 2002 and October 2013 (11 years), 293 items were surveyed weekly, including 38 clinical samples, 86 pathogens, 79 diagnosis tests, and 39 antibacterial resistance patterns. The mean duration of surveillance was 7.6 years (range, 1 month-10.9 years). A total of 108,427 Microsoft Excel file cells were filled with counts of clinical samples, and 110,017 cells were filled with counts of diagnoses. A total of 1,390,689 samples were analyzed. Among them, 172,180 were found to be positive for a pathogen. EPIMIC generated a mean number of 0.5 alert/week on abnormal events.

CONCLUSIONS

EPIMIC proved to be efficient for real-time automated laboratory-based surveillance and alerting at our university hospital clinical microbiology laboratory-scale. It is freely downloadable from the following URL: http://www.mediterranee-infection.com/article.php?larub=157&titre=bulletin-epidemiologique (last accessed: 20/11/2015).

Genetic resistance: tolerance to vector-borne diseases and the prospects and challenges of genomics

Vector-borne diseases in cattle and small ruminants (e.g. trypanosomosis, Rift Valley fever and East Coast fever) are associated with major economic losses in tropical countries, and particularly on the African continent. A variety of control strategies (e.g. management, vaccination and/or acaricide treatments) are used to minimise their negative impacts. These strategies are often associated with environmental, technical and/or economic drawbacks. However, several indigenous livestock populations have been reported to show a level of genetic tolerance or resistance to such disease challenges (e.g. trypanotolerant N'Dama cattle and Djallonké sheep). Use of these populations represents a sustainable alternative approach to minimising the negative impact of such infection/infestation on livestock production. This review summarises the current understanding of the genetic control of these adaptations, identifies knowledge gaps and critically examines the possible impacts of genomics approaches to the genetic improvement of tolerance and/or resistance to vector-borne diseases.

Metagenomics: A New Way to Illustrate the Crosstalk between Infectious Diseases and Host Microbiome

Microbes have co-evolved with human beings for millions of years. They play a very important role in maintaining the health of the host. With the advancement in next generation sequencing technology, the microbiome profiling in the host can be obtained under different circumstances. This review focuses on the current knowledge of the alteration of complex microbial communities upon the infection of different pathogens, such as human immunodeficiency virus, hepatitis B virus, influenza virus, and Mycobacterium tuberculosis, at different body sites. It is believed that the increased understanding of the correlation between infectious disease and the alteration of the microbiome can contribute to better management of disease progression in the future. However, future studies may need to be more integrative so as to establish the exact causality of diseases by analyzing the correlation between microorganisms within the human host and the pathogenesis of infectious diseases.

Chronic lung infection by Pseudomonas aeruginosa biofilm is cured by L-Methionine in combination with antibiotic therapy

Bacterial biofilms are associated with 80-90% of infections. Within the biofilm, bacteria are refractile to antibiotics, requiring concentrations >1,000 times the minimum inhibitory concentration. Proteins, carbohydrates and DNA are the major components of biofilm matrix. Pseudomonas aeruginosa (PA) biofilms, which are majorly associated with chronic lung infection, contain extracellular DNA (eDNA) as a major component. Herein, we report for the first time that L-Methionine (L-Met) at 0.5 μM inhibits Pseudomonas aeruginosa (PA) biofilm formation and disassembles established PA biofilm by inducing DNase expression. Four DNase genes (sbcB, endA, eddB and recJ) were highly up-regulated upon L-Met treatment along with increased DNase activity in the culture supernatant. Since eDNA plays a major role in establishing and maintaining the PA biofilm, DNase activity is effective in disrupting the biofilm. Upon treatment with L-Met, the otherwise recalcitrant PA biofilm now shows susceptibility to ciprofloxacin. This was reflected in vivo, in the murine chronic PA lung infection model. Mice treated with L-Met responded better to antibiotic treatment, leading to enhanced survival as compared to mice treated with ciprofloxacin alone. These results clearly demonstrate that L-Met can be used along with antibiotic as an effective therapeutic against chronic PA biofilm infection.

[THE CONDITION AND TENDENCIES OF DEVELOPMENT OF CLINICAL AND SANITARY MICROBIOLOGY IN THE RUSSIAN FEDERATION AND PROBLEM OF IMPORT SUBSTITUTION]

The import substitution becomes one of the strategic tasks of national economy as a result of prolongation of economic sanctions concerning the Russian Federation of part of the USA, EU countries, Japan and number of other countries. It is not proper to be limited in import substitution only by goods because in conditions ofsanctions when access toforeign technologies is complicated Russia is needed to substitute foreign technologies by national designs in faster manner One of directions of effective import substitution is localization of production of laboratory equipment and consumables for clinical and sanitary microbiology on the territory ofthe Russian Federation and countries of Customs union. In Russia, in the field ofdiagnostic of dangerous and socially significant infections, all components for import substitution to implement gene diagnostic, immune diagnostic. bio-sensory and biochip approaches, isolation and storage of live microbial cultures, implementation of high-tech methods of diagnostic are available. At the same time, national diagnostic instrument-making industry for microbiology is factually absent. The few devices of national production more than on 50% consist of import components. The microbiological laboratories are to be equipped only with import devices of open type for applying national components. The most perspective national designs to be implemented are multiplex polimerase chain reaction test-systems and biochips on the basis of national plotters and readers. The modern development of diagnostic equipment and diagnostic instruments requires supplement of national collections of bacterial and viral pathogens and working-through of organizational schemes of supplying collections with strains. The presented data concerning justification of nomenclature of laboratory equipment and consumables permits to satisfy in fill scope the needs of clinical and sanitary microbiology in devices, growth mediums, consumables of national production and to refuse import deliveries without decreasing quality of microbiological analysis. This approach will ensure appropriate response to occurring challenges and new biological dangers and maintenance of biosecurity of the Russian Federation at proper level.