Laboratory Identification Research Articles

Commentary on clinical utility of whole genome sequencing and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

3The present study is commentary and aims to evaluate the practical application of Whole Genome Sequencing (WGS) and Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) in clinical microbiology. The MALDI-TOF MS method has been replaced cultural and biochemical tests for species identification in most laboratories worldwide. Moreover, WGS has elevated the discriminatory power by detection of single nucleotide polymorphisms (SNPs), and helped with the identification of microorganisms that were misidentified by previous culture and biochemical tests. Moreover, WGS can be used in epidemiological studies (e.g. clinical outbreaks) by tracking of phylogenetic maps and analyzing SNP distance; antimicrobial resistance studies such as the study of antimicrobial resistance genes, e.g. CTX-M, NDM, KPC, or OXA; and the study of recombination of plasmid or insertion sequence (IS) elements to elucidate the mechanism of antimicrobial resistance. MALDI-TOF technology is used for bacterial or fungal species identification in most laboratories. VITEK MS (bioMerieux) and Biotyper (Bruker Daltonics) are examples of commercially available MALDI-TOF MS systems. The technique has been used for direct identification of organisms from blood culture bottles, markedly shortening the identification time. Beta-lactamases or carbapenemases have been detected by analyzing specific protein peaks using MALDI-TOF MS. Shiga toxin-producing Escherichia coli, Salmonella serotype, and Vibrio phenotypes can also be detected.

MALDI-TOF MS in the Microbiology Laboratory: Current Trends.

Within less than a decade matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has become a gold standard for microbial identification in clinical microbiology laboratories. Besides identification of microorganisms the typing of single strains as well as the antibiotic and antimycotic resistance testing has come into focus in order to speed up the microbiological diagnostic. However, the full potential of MALDI-TOF MS has not been tapped yet and future technological advancements will certainly expedite this method towards novel applications and enhancement of current practice. So, the following chapter shall be rather a brainstorming and forecast of how MALDI-TOF MS will develop to influence clinical diagnostics and microbial research in the future. It shall open up the stage for further discussions and does not claim for overall validity.

RHINORRHEA: SYMPTOM OF MANY DISEASES!

Rhinorrhea is a term for abundant mucous (watery) discharge from the nasal cavity, which originated from the Greek word «rhoia» (flow, discharge). Rhinorrhea is usually a symptom of acute diseases. However, less pronounced manifestations can be a sign of various chronic diseases not only of the nasal cavity, but of other organs and systems. In order to identify the causes for rhinorrhea, you may need to take an additional examination and a detailed history of occupational diseases, medications taken, etc. The patients should receive symptomatic treatment while awaiting the laboratory test results and identification of the causes for the disease.

Clinical Characteristics and Laboratory Identification of Aerococcus Infections: An Australian Tertiary Centre Perspective.

Aerococci uncommonly cause urinary tract (UTI) and bloodstream infections (BSI). The clinical characteristics and laboratory identification rates of Aerococcus in the Australian context are unknown. A retrospective observational cohort study of patients with positive Aerococcus cultures between 2010 and 2015 was performed. Patients were analysed according to predefined “asymptomatic bacteriuria,” “UTI,” and “BSI” groups. Forty-seven [40 (85%) for urine and 7 (15%) for blood] isolates were identified [38% male, median age of 79 (IQR 62–85) years], with corresponding identification rates of 24.2/100,000/year for urine (0.02%) and 7.3/100,000/year for blood cultures (0.007%). Since the use of matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF MS) identification rate in urine has increased from 14.7/100,000/year to 32/100,000/year (p = 0.02). For urine isolates, 14 (35%) met the definition for UTI whilst 26 (65%) were “asymptomatic bacteriuria.” Underlying urological abnormalities, catheterisation, and polymicrobial growth were common. Seventy percent of bacteriuria was treated regardless of colonisation or active infection status. Symptomatic patients were more likely to receive treatment (OR 7.2, 95% CI 1.4–35.3). In patients with BSI, 1 (14.2%) had endocarditis and 1 (14.2%) died. The majority of isolates were susceptible to penicillin (11/12 tested, 92%).

Different Incidences of Acute Bacterial Meningitis in Children of Central Punjab in Pakistan

Background: Acute Bacterial Meningitis (ABM) is a serious public health problem demanding early diagnosis, effective treatment, prevention, and control. Approximately 70 percent of meningitis cases occur in children under the age of 5 and in adults over the age of 60. Objective: To evaluate the different incidences of Acute bacterial meningitis in children of Pakistan. Setting: different hospitals in central Punjab, Pakistan. Material and methods: It's a retrospective study of case files of admitted children in hospitals of different cities of Pakistan. In this study, we evaluated 135 children's for symptoms of meningitis, diagnosis tests, therapy and also some co-morbid diseases related to ABM. Microsoft excel version 2013 was used for statistical analysis. Main outcome measures: Prevalence of Acute bacterial meningitis in different age groups of children, diagnostic tests, and complications related to acute bacterial meningitis are main findings. Results and discussion: Prevalence of ABM was more in neonates than others. For diagnosis meningitis sign test performed on most patients was not much information, so we can't diagnose complications relating to ABM. Unsatisfactory empirical therapy was given to patients for their treatment. Due to incomplete laboratory identification test, some co-morbid diseases and complications were also observed. There was the total lack of mode of preventions for ABM. Conclusion: It concluded that ABM is serious, death causing disease having the high prevalence in neonates. Furthermore improper diagnosis and non-standard management and treatment cause the disease to be an economic and social burden on the society by increasing long term complications and increase death rate in children.

Neglected tropical parasitic infectious diseases: An insight in to human strongyloidiasis

Among many infectious diseases prevalent in the world, a few are emerging and emerging infectious diseases, which include the influenza virus. There are some other infections, which are spread throughout the world causing pandemics like the human immunodeficiency virus (HIV). Human parasitic infectious diseases assume greater significance in public health perspective, as they contribute to majority of the morbidity especially in the developing and economically weak nations usually affecting the pediatric age and the young adults, as well as immunocompromised individuals. Human strongyloidiasis is one such parasitic disease, which is least studied and under reported undermining its clinical significance. This manuscript attempts to reinvent the pathogenic potential of Strongyloides stercoralis infection, laboratory identification of human strongyloidiasis and future perspectives.

Molecular identification of variety purity in a cotton hybrid with unknown parentage using DNA-SSR markers.

Molecular identification of hybrid purity is difficult in regional trials of cotton varieties and hybrid trials. In particular, the molecular detection of hybrid purity has not yet been reported in the case of unknown parentage. In this study, we screened 5000 pairs of primers and chose 17 pairs of core simple sequence repeat (SSR) primers to determine the F1 purity of Han6402. The results showed that the purity based on SSR markers reached 100%. Twelve of the 17 pairs of primers exhibited co-dominant banding patterns, and 5 showed non-co-dominant banding patterns. Moreover, we constructed an F1 SSR fingerprinting profile that enabled the identification of the authenticity of Han 6402. Using these primers, we subsequently detected 44 individual F2 seedlings, and the results exhibited different extents of separation, in which the majority of genotypes were heterozygous with co-dominance at most of the loci that differed from each other. The results validated the underlying heterozygous status of the F2 population at the molecular level. Therefore, we conclude that the set of core SSR primers can be used for the laboratory identification of the authenticity and purity of cotton hybrids, not only for distinguishing Fl hybrids or segregating F2 populations, but also for detecting volunteer seeds as fake F1 hybrids in the cotton hybrid industry, based on the hybrid fingerprinting.

Role of Atypical Pathogens in the Etiology of Community-Acquired Pneumonia.

Atypical pneumonia has been described for over 100 years, but some of the pathogens attributed to it have been identified only in the past decades. The most common pathogens are Chlamydia pneumoniae, Mycoplasma pneumoniae, and Legionella pneumophila. The epidemiology and pathophysiology of these three pathogens have been studied since their discovery, and are reviewed herein to provide better insight when evaluating these patients, which hopefully translates into improved care. The incidence of atypical pathogens has been shown to be approximately 22% worldwide, but this probably varies with location. The history and physical exam of a patient with atypical pneumonia reveals how patients share many signs and symptoms with their counterpart patients who have typical pneumonias; therefore, the diagnosis primarily depends on laboratory identification, which is evolving and improving. What started out as simple, but difficult to yield cultures, has progressed to modern molecular-based testing assays. Treatment is missed if an empiric regimen includes only monotherapy with a β-lactam antimicrobial; so, many country guidelines, including the Infectious Diseases Society of America/American Thoracic Society guidelines for community-acquired pneumonia, recommend using a regimen containing either a macrolide or a fluorinated quinolone. Once an atypical pathogen has been identified, evidence trends toward favoring a quinolone, but more data are needed to confirm. The concept of using combination therapy in severe patients is also explored.

Detection of Klebsiella pneumoniae carbapenemases and metallo-β-lactamases among Klebsiella pneumoniae isolates from hospitalized patients at Menoufia University Hospitals, Egypt

Objectives The aim of the study was to determine the incidence of carbapenem resistance among Klebsiella pneumoniae isolates in Menoufia University Hospitals and detect the production of Klebsiella pneumoniae carbapenemases (KPCs) and metallo- b -lactamases (M b Ls) using phenotypic and molecular methods and correlate their presence with in-vitro susceptibility to carbapenems. Background Carbapenem-hydrolyzing b -lactamases are the most powerful b -lactamases. KPCs and M b Ls are able to hydrolyze carbapenems, which cause resistance to multiple classes of antibiotics. Materials and methods The study was conducted on 128 K. pneumoniae isolates. Carbapenemase production was detected by antibiotic susceptibility testing against imipenem (IPM), meropenem, and ertapenem and by IPM minimal inhibitory concentration assays. Results were confirmed by the modified Hodge test, the phenylboronic acid combined disk (PBA-CD) test, and the IPM/EDTA combined disk (IPM/EDTA-CD) test. Detection of carbapenemase genes (blaKPC, blaVIM, and blaIMP) was performed by multiplex PCR. Results Eighty K. pneumoniae isolates were reported as IPM resistant. Class A carbapenemases (KPCs) were detected in 35% of IPM-resistant K. pneumoniae by the PBA-CD test. Class B carbapenemases (M b Ls) were detected in 48.8% of IPM-resistant K. pneumoniae by the IPM/EDTA-CD test. Age, long hospital stay, invasive procedures, and history of drug intake (carbapenem) were high-risk factors for IPM-resistant K. pneumoniae. Among IPM-resistant isolates, 17.5% were positive for the blaKPC gene and 43.75% were positive for the blaVIM and blaIMP genes. In relation to PCR, the sensitivity and specificity of the PBA-CD test were 85.7 and 75.8%, respectively, whereas for the IPM/EDTA-CD test sensitivity and specificity were 94.3 and 86.7%, respectively. Conclusion Laboratory identification of carbapenemase-harboring clinical isolates is necessary for implementing contact precautions, for outbreak detection, and for proper choice of effective therapy. Phenotypic and molecular-based techniques identify carbapenemase producers with variable efficiencies.

Mass spectrometry methods for predicting antibiotic resistance.

Developing elaborate techniques for clinical applications can be a complicated process. Whole-cell MALDI-TOF MS revolutionized reliable microorganism identification in clinical microbiology laboratories and is now replacing phenotypic microbial identification. This technique is a generic, accurate, rapid, and cost-effective growth-based method. Antibiotic resistance keeps emerging in environmental and clinical microorganisms, leading to clinical therapeutic challenges, especially for Gram-negative bacteria. Antimicrobial susceptibility testing is used to reliably predict antimicrobial success in treating infection, but it is inherently limited by the need to isolate and grow cultures, delaying the application of appropriate therapies. Antibiotic resistance prediction by growth-independent methods is expected to reduce the turnaround time. Recently, the potential of next-generation sequencing and microarrays in predicting microbial resistance has been demonstrated, and this review evaluates the potential of MS in this field. First, technological advances are described, and the possibility of predicting antibiotic resistance by MS is then illustrated for three prototypical human pathogens: Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. Clearly, MS methods can identify antimicrobial resistance mediated by horizontal gene transfers or by mutations that affect the quantity of a gene product, whereas antimicrobial resistance mediated by target mutations remains difficult to detect.

Characteristics of invasive Acinetobacter species isolates recovered in a pediatric academic center.

BackgroundAcinetobacter species are associated with increasing mortality due to emerging drug-resistance. Pediatric Acinetobacter infections are largely undefined in developed countries and clinical laboratory identification methods do not reliably differentiate between members of the Acinetobacter calcoaceticus-baumannii complex, leading to improper identification. Therefore we aimed to determine risk factors for invasive Acinetobacter infections within an academic, pediatric setting as well as defining microbiologic characteristics of predominant strains.MethodsTwenty-four invasive Acinetobacter isolates were collected from 2009–2013. Comparative sequence analysis of the rpoB gene was performed coupled with phenotypic characterization of antibiotic resistance, motility, biofilm production and clinical correlation.ResultsAffected patients had a median age of 3.5 years, and 71 % had a central catheter infection source. rpoB gene sequencing revealed a predominance of A. pittii (45.8 %) and A. baumannii (33.3 %) strains. There was increasing incidence of A. pittii over the study. Two fatalities occurred in the A. pittii group. Seventeen percent of isolates were multi-drug resistant. A pittii and A. baumannii strains were similar in motility, but A pittii strains had significantly more biofilm production (P value = 0.018).ConclusionsA. pittii was the most isolated species highlighting the need for proper species identification. The isolated strains had limited acute mortality in children, but the occurrence of more multi-drug resistant strains in the future is a distinct possibility, justifying continued research and accurate species identification.Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-016-1678-9) contains supplementary material, which is available to authorized users.

Classification of Aeromonas spp. isolated from water and clinical sources and distribution of virulence genes.

In this work, 84 isolates of aeromonads were isolated from water and clinical samples, identified, and characterized. Identification was based on routine phenotyping combined with multiplex PCR. In this study, multiplex PCR was retested and reevaluated and its identification key was enhanced by 17 newly described species and five subspecies. Identification score increased from 36% (only phenotyping) to 90% when supported with multiplex PCR. Further description of isolates included detection of eight virulence genes. These genes were overall present in 46% (act), 2.4% (ast), 80% (alt), 40% (ahh1), 20% (asa1), 69% (pla/lip/lipH3/alp-1), 69% (ser), and 81% (fla), and no significant differences between water and clinical isolates were found. Results of this work show that the proper combination of different approaches is necessary for final identification of Aeromonas spp. at the species level. Multiplex PCR was shown to have limits in final identification, specifically inability to distinguish four species pairs and one triplet as their gene profiles are identical. However, it seems to be rapid and easy to do method able to support routine biochemical identification in laboratories. Moreover, our results supported previous proposal of reclassification of "Aeromonas hydrophila subsp. dhakensis" and "Aeromonas aquariorum" as identical species.

Food safety start-up raises $9 million

Branford, Conn.-based start-up Ancera has raised $9 million in a first round of funding to help it commercialize technology that swiftly identifies microbial food safety hazards such as Listeria, Salmonella, and E. coli. Investors included the food safety companies Packers Sanitation Services and Metabiota. Current detection systems require an often days-long incubation followed by a multistep laboratory identification process. Ancera’s PIPER technology uses a ferrofluid and magnet to manipulate, sort, and count viable pathogens from a sample.

Toward the laboratory identification of [O,N,S,S] isomers: Implications for biological NO chemistry.

Benchmark ab initio calculations are performed to investigate the stable isomers of [O,N,S,S]. These computations are carried out using coupled cluster (RCCSD(T)) and explicitly correlated coupled cluster methods (RCCSD(T)-F12). In addition to the already known cis isomer of SSNO, nine other stable forms are predicted. The most stable isomer is cis-OSNS. Nine structures are chain bent-bent with relatively large dipole moments which make them detectable, as cis-SSNO, by infrared, far-infrared, and microwave spectroscopies. We found also a C2v isomer (NS2O). Since these species are strongly suggested to play an important role as intermediates during the bioactive reaction products of the NO/H2S interaction, the rotational and vibrational spectroscopic parameters are presented to help aid the in vivo identification and assignment of these spectra. Results from this work show that [O,N,S,S] may play key roles during nitric oxide transport and deliver in biological media, as well as, provide an explanation for the weak characteristic of disulfide bridges within proteins.

Time series analysis of RSV and bronchiolitis seasonality in temperate and tropical Western Australia

Respiratory syncytial virus (RSV) causes respiratory illness in young children and is most commonly associated with bronchiolitis. RSV typically occurs as annual or biennial winter epidemics in temperate regions, with less pronounced seasonality in the tropics. We sought to characterise and compare the seasonality of RSV and bronchiolitis in temperate and tropical Western Australia. We examined over 13 years of RSV laboratory identifications and bronchiolitis hospitalisations in children, using an extensive linked dataset from Western Australia. We applied mathematical time series analyses to identify the dominant seasonal cycle, and changes in epidemic size and timing over this period. Both the RSV and bronchiolitis data showed clear winter epidemic peaks in July or August in the southern Western Australia regions, but less identifiable seasonality in the northern regions. Use of complex demodulation proved very effective at comparing disease epidemics. The timing of RSV and bronchiolitis epidemics coincided well, but the size of the epidemics differed, with more consistent peak sizes for bronchiolitis than for RSV. Our results show that bronchiolitis hospitalisations are a reasonable proxy for the timing of RSV detections, but may not fully capture the magnitude of RSV epidemics.

Utility of 16S rDNA Sequencing for Identification of Rare Pathogenic Bacteria.

Phenotypic identification systems are established methods for laboratory identification of bacteria causing human infections. Here, the utility of phenotypic identification systems was compared against 16S rDNA identification method on clinical isolates obtained during a 5-year study period, with special emphasis on isolates that gave unsatisfactory identification. One hundred and eighty-seven clinical bacteria isolates were tested with commercial phenotypic identification systems and 16S rDNA sequencing. Isolate identities determined using phenotypic identification systems and 16S rDNA sequencing were compared for similarity at genus and species level, with 16S rDNA sequencing as the reference method. Phenotypic identification systems identified ~46% (86/187) of the isolates with identity similar to that identified using 16S rDNA sequencing. Approximately 39% (73/187) and ~15% (28/187) of the isolates showed different genus identity and could not be identified using the phenotypic identification systems, respectively. Both methods succeeded in determining the species identities of 55 isolates; however, only ~69% (38/55) of the isolates matched at species level. 16S rDNA sequencing could not determine the species of ~20% (37/187) of the isolates. The 16S rDNA sequencing is a useful method over the phenotypic identification systems for the identification of rare and difficult to identify bacteria species. The 16S rDNA sequencing method, however, does have limitation for species-level identification of some bacteria highlighting the need for better bacterial pathogen identification tools.

An epidemiological study of animals dermatomycoses in Iran

To determine the fungal species isolated from skin lesions of different animals suspected of having dermatomycoses and their prevalence in different regions of Iran. A total of 1011 animals (292 dogs, 229 cats, 168 horses, 100 camels, 98 cows, 60 squirrels, 37 birds, 15 sheep, 6 goats, 5 rabbits and 1 fox) suspected of having dermatomycoses were examined. The samples were obtained by plucking the hairs and feathers with forceps around the affected area and scraping the epidermal scales with a sterile scalpel blade. All collected samples were analyzed by direct microscopy and culture. Laboratory identification of the fungal isolates was based on their colonial, microscopic and biochemical characteristics. Fungal agents were recovered from 553 (54.7%) animals suspected of having dermatomycoses. Of 553 confirmed cases, 255 (49.7%) were positive for dermatophytosis, 251 (45.4%) for Malassezia dermatitis, 14 (2.5%) for candidiasis, 12 (2.2%) for aspergillosis and 1 (0.2%) for zygomycosis. Cats (36.3%) were the most prevalent infected animals, followed by camels (13.4%), dogs (12.8%), horses (12.5%), cows (12.3%), squirrels (5.4%), birds (3.6%), sheep (2%), goats (1.1%), rabbits (0.4%) and fox (0.2%). Microsporumcanis (M.canis) was the most frequent fungus isolated from dogs and fox, Malasseziapachydermatis (M.pachydermatis) from cats, horses and squirrels, Trichophyton verrucosum (T.verrucosum) from cows and camels, T.mentagrophytes var. mentagrophytes from sheep, goats and rabbits, and Aspergillus fumigatus (A.fumigatus) from birds. The results suggested that periodic screening of animals suspected of having dermatomycoses and necessary treatments could help in the management of their public health problem.

Clinical presentation, management and outcomes of influenza in Africa: systematic review, 2009-2014

Background: This paper aims to review the effectiveness of diagnostic and management of influenza in Africa, specifically mortality, treatment and outcomes. Methods & Materials: In two times, we searched the online databases PubMed™ and Scopus™ for articles and abstracts published in English and French between January 2003 and December 2014, with the following terms :(influenza OR flu) AND (clinical) AND (management OR outcomes) AND (Africa) at the first time, and online databases of internationals conferences for the abstract who do not meet the consent of the editor of scientific journals at the second time. Cross- sectional, longitudinal studies and randomized clinical trial on influenza were selected when clinical, management and outcomes were reported. Results: Patients with influenza were more likely to present with fever as initial and main symptom, followed by shortness of breathing, cough, muscle & joint pain, sore throat, hemoptysis, dyspnea, and gastrointestinal complaints (vomiting and diarrhea), pneumonic infiltrations in the chest. For the diagnostic nasal secretions were collected in patients presenting with flu syndrome and follow-up by laboratory identification of viruses was performed by the ELISA technique using anti-A and anti-B monoclonal antibodies (immunocapture) and by isolation on MDCK cells, quantitative real-time polymerase chain reaction (qRT-PCR) assay of the upper respiratory tract is used increasingly to diagnose lower respiratory tract infections. Amongst samples analyzed for influenza; 1–45% had laboratory-confirmed influenza infections; including influenza virus A (H3N2) type, A (H1N1) type, A (H5N1) type and influenza virus B. All confirmed cases received oseltamivir in any setting. Among groups known to be at high risk of influenza-associated complications, Included age<5 years, asthma, cardiac disease, pregnancy, diabetes mellitus, active pulmonary tuberculosis and chronic malnutrition. Mortality rate was 28 – 68.4%. Female sex, age>15 years, and receiving the first dose of oseltamivir>2 days after illness onset, non vaccination against the virus the circulating influenza, cardiovascular complications and ventilatory associated pneumonia were identified as mortality predicting factors. Conclusion: The classic presentation of influenza in Africa is most often confused with malaria, low technical platforms limit the detection of virus in the samples. The progressive creation of influenza sentinel surveillance system will improve care in Africa.

Activity of Some Natural Oils on Dermatophytes Isolated from Assuit University Hospitals

Background: Dermatophytosis constitutes a major public health problem in different countries. The most common factors affecting the distribution and transmission of dermatophyte infections are climatic conditions, general hygiene, and animal contact. In Egypt, the prevalence of dermatophytosis has not been well clarified. Several antifungal agents are available to manage these infections but drug resistance, severe side effects and its very poor penetration can result in treatment failure. Objectives: This study aimed to detect the prevalence of dermatophyte infections in Assuit University Hospital and to screen for anti-dermatophytic activity of some plant essential oils to discover their medicinal potential for future applications as antifungal agents. Methodology: Samples were collected from 50 patients attending dermatology clinic at Assuit University Hospital and clinically diagnosed as tinea infections. Isolation and laboratory identification of dermatophytes were performed by direct microscopic examination, Sabouraud , s dextrose agar and rice grains medium culture. Extracellular enzymatic activities (urease, lipase and protease) were tested. Some natural oils (dill seed, garlic, ginger, nigella seed, olive, peppermint and riccinus) were screened for their anti-dermatophytic activities by disc diffusion methods. Result: Dermatophytosis was diagnosed in 40 (80%) of all patients examined, the prevalence of dermatophytosis in male (57.5%) was higher than in female (42.5%), the most common dermatophyte infection diagnosed was tinea capitis (65%), followed by tinea pedis (17.5%). Four species belonging to two genera were identified, 20 (50%) T. violaceum, 14 (35%) M. canis, 3 (7.5%) T. mentagrophytes and 3 (7.5%) T. rubrum. All tested oils have dermatophytic activities except dill and olive oils. Nigella oil was the most active against growth of T. mentagrophytes and T. rubrum. Ginger oil was the most active against T. violaceum and M. canis. Garlic and ginger oils had active effect against T. rubrum . Conclusion: Nigella, ginger and garlic oils had proved a promising effectiveness against dermatophytes and can be used in the development of new anti-dermatophytic preparations.

Rationale for the selective administration of tranexamic acid to inhibit fibrinolysis in the severely injured patient.

Postinjury fibrinolysis can manifest as three distinguishable phenotypes: 1) hyperfibrinolysis, 2) physiologic, and 3) hypofibrinolysis (shutdown). Hyperfibrinolysis is associated with uncontrolled bleeding due to clot dissolution; whereas, fibrinolysis shutdown is associated with organ dysfunction due to microvascular occlusion. The incidence of fibrinolysis phenotypes at hospital arrival in severely injured patients is: 1) hyperfibrinolysis 18%, physiologic 18%, and shutdown 64%. The mechanisms responsible for dysregulated fibrinolysis following injury remain uncertain. Animal work suggests hypoperfusion promotes fibrinolysis, while tissue injury inhibits fibrinolysis. Clinical experience is consistent with these observations. The predominant mediator of postinjury hyperfibrinolysis appears to be tissue plasminogen activator (tPA) released from ischemic endothelium. The effects of tPA are accentuated by impaired hepatic clearance. Fibrinolysis shutdown, on the other hand, may occur from inhibition of circulating tPA, enhanced clot strength impairing the binding of tPA and plasminogen to fibrin, or the inhibition of plasmin. Plasminogen activator inhibitor -1 (PAI-1) binding of circulating tPA appears to be a major mechanism for postinjury shutdown. The sources of PAI-1 include endothelium, platelets, and organ parenchyma. The laboratory identification of fibrinolysis phenotype, at this moment, is best determined with viscoelastic hemostatic assays (TEG, ROTEM). While D-dimer and plasmin antiplasmin (PAP) levels corroborate fibrinolysis, they do not provide real-time assessment of the circulating blood capacity. Our clinical studies indicate that fibrinolysis is a very dynamic process and our experimental work suggests plasma first resuscitation reverses hyperfibrinolysis. Collectively, we believe recent clinical and experimental work suggest antifibrinolytic therapy should be employed selectively in the acutely injured patient, and optimally guided by TEG or ROTEM.