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NDM - 1 Challenges to Medical Microbiology

NDM - 1 Challenges to Medical Microbiology

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NDM - 1 Challenges to Medical Microbiology

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  1. NDM-1GROWING CONCERNSNeed for Modernization of Diagnostic Microbiology Laboratories Dr.T.V.Rao MD Dr.T.V.Rao MD

  2. The Lancet Opens the Pandora box • Gram-negative Enterobacteriaceae with resistance to carbapenems conferred by New Delhi metallo-β-lactamase 1 (NDM-1) are potentially a major global health problem. We investigated the prevalence of NDM-1, in multidrug-resistant Enterobacteriaceae in India, Pakistan, and the UK. Dr.T.V.Rao MD

  3. Travel makes patients venerable • The superbug called New Delhi metallo-beta-lactamase, or NDM-1, was identified in 50 people who traveled to India or Pakistan for surgery and then returned to the United Kingdom, British scientists reported in the journal Lancet Infectious Diseases Dr.T.V.Rao MD

  4. Naming the strain as New Delhi creates controversy • The gene was named after New Delhi, the capital city of India, as it was first described by Yong et al. in 2009 in a Swedish national who fell ill with an antibiotic-resistant bacterial infection that he acquired in India . The infection was unsuccessfully treated in a New Delhi hospital and after the patient's repatriation to Sweden, a carbapenem-resistant Klebsiella pneumoniaestrain bearing the novel gene was identified. The presenting authors concluded that the new resistance mechanism "clearly arose in India, but there are few data arising from India to suggest how widespread it is." Dr.T.V.Rao MD

  5. Bugs becomes Superbugs • Antibiotic resistance develops through gene action or plasmid exchange between bacteria of the same species. If a bacterium carries several resistance genes, it is called multiresistant or, informally, a superbug. Dr.T.V.Rao MD

  6. CDC Reports Three Enterobacteriaceae isolates carrying a newly described resistance mechanism, the New Delhi metallo-beta-lactamase (NDM-1) , were identified from three U.S. states at the CDC antimicrobial susceptibility laboratory. This is the first report of NDM-1 in the United States, and the first report of metallo-beta-lactamase carriage among Enterobacteriaceae in the United States Dr.T.V.Rao MD

  7. Mark Toleman of Britain's Cardiff University School of Medicine, creates concerns ? • The inhabitants of New Delhi are continually being exposed to multidrug-resistant and NDM 1-positive bacteria," said Mark Toleman of Britain's Cardiff University School of Medicine, who published the findings in a study on Thursday. Dr.T.V.Rao MD

  8. Toleman’s Study a Concern to India • Toleman’s study, carried out with Cardiff University’s Timothy Walsh and published in The Lancet Infectious Diseases journal, investigated how common NDM 1-producing bacteria are in community waste seepage — such as water pools or rivulets in streets — and tap water in urban New Delhi. Dr.T.V.Rao MD

  9. Facts Reported on the Present Study • In September and October 2010, Walsh’s research team collected 50 samples from public drinking water taps in New Delhi and 171 samples from “seepage,” standing water that had pooled near public areas, both of which are used by residents for drinking, washing and/or other household functions. The scientists found bacterial strains with the NDM-1 mutation in two of the drinking water samples and in 51 of the seepage samples. For comparison, they collected 70 samples from Cardiff’s water supply and found no evidence of bacteria with NDM-1 mutations. Dr.T.V.Rao MD

  10. Facts on NDM-1 are Concern to the National Health • Speech is silver • Silence is Gold • Ignoring the facts is Dangerous NDM - 1 Dr.T.V.Rao MD

  11. Why Microbiologists are Important in the Changing Scenario • Adequate clinical management of infectious diseases relies primarily on the accurate identification of the causal micro­organism and the production of reliable information on its antimicrobial susceptibility Dr.T.V.Rao MD

  12. Now Clinicians Need Faster Diagnostic Information • Tra­ditional diagnostic methods in microbiology have lim­ited the ability of laboratories to provide doctors with timely and clinically relevant information, but recent technology provides results in minutes or hours rather than days or weeks. Dr.T.V.Rao MD

  13. Improving the Standards in Diagnostic Microbiology Dr.T.V.Rao MD

  14. Safety of the Laboratory Personal A Top Priority • The protection of personnel and the immediate laboratory environment from exposure to infectious agents is provided by both good microbiological technique and the use of appropriate safety equipment. The use of vaccines may provide an increased level of personal protection. Dr.T.V.Rao MD

  15. Let our Policy to start with Containment • The term "containment" is used in describing safe methods for managing infectious materials in the laboratory environment where they are being handled or maintained. The purpose of containment is to reduce or eliminate exposure of laboratory workers, other persons, and the outside environment to potentially hazardous agents. Dr.T.V.Rao MD

  16. Implementing Biosaftey at Medical Establishments in India • It is time to educate on Biosafety issues. Document the Information regarding the Biosaftey equipment available in the Hospital, Colleges, if not, to do at the earliest, and concerns of the Health of the Laboratory personal should be made mandatory. Dr.T.V.Rao MD

  17. Specimen collection Continues to be Most Neglected part of Diagnostic Microbiology Can be Improved Dr.T.V.Rao MD

  18. Collecting the correct specimen most neglected part of Diagnostic Microbiology • Endocervical swabs for GC • Per nasal swabs for pertussis • whole EMU for TB • Sputum , not saliva • Blood culture bottles, not clotted blood • Correctly timed Gentamicin assays • Pus, not swabs • Major value of the Diagnostic Microbiology is lost in unscientific methods, left casually to ill trained staff Dr.T.V.Rao MD

  19. Getting the specimen to the laboratory • Problems in delay or inappropriate storage• delay in diagnosis & treatment • pathogens die • contaminants overgrow • Blood cultures directly into incubator not refrigerator! • CSF straight to lab • Don't put an entire surgical specimen into formalin! • Send a portion to microbiology in a sterile container Dr.T.V.Rao MD

  20. Collecting the specimen correctly • Take an mid-stream urine • avoids contamination with perineal flora • CSF • Avoid contamination • Avoid bloody tap • Throat swab • Make the patient gag! • Blood cultures • Avoid contamination with skin organisms Dr.T.V.Rao MD

  21. Labelling Specimens & Infection Control • Please be considerate to lab staff!! • Label hazardous specimens • Don't send specimens to the lab without proper packing • Leaking or blood-stained specimens are not acceptable!!! Dr.T.V.Rao MD

  22. Factors limiting usefulness of bacteriological investigations What is going Wrong • Wrong sample • e.g. saliva instead of sputum • Delay in transport / inappropriate storage • e.g. CSF • Overgrowth by contaminants • e.g. blood cultures • Insufficient sample / sampling error • e.g.in mycobacterial disease • Patient has received antibiotics Dr.T.V.Rao MD

  23. ANTIMICROBIAL SUSCEPTIBILITY TESTING The major control on use , misuse of Antibiotics can be controlled with Good Practices Dr.T.V.Rao MD

  24. ANTIMICROBIAL SUSCEPTIBILITY TESTING • The role of antimicrobial susceptibility tests to guide empirical therapy, to refine therapy once pathogens have been isolated and identified, and to detect new types of antimicrobial resistance is well established. Other roles of antimicrobial susceptibility testing for patient care, such as development of cumulative Antibiograms, creation of antimicrobial formularies, and detection of new antimicrobial resistance strains or trends, are also well established. Dr.T.V.Rao MD

  25. Quality Control on Antimicrobial testing is crucial • Generating accurate and reproducible antimicrobial susceptibility test data requires perhaps the most extensive QC program used in clinical laboratories today Dr.T.V.Rao MD

  26. Adherence to CLSI Guidelines .. • The CLSI publishes guidelines for the QC of antimicrobial susceptibility tests . These guidelines are extensive and require rigorous adherence to each step of testing for results to be accurate and reproducible. Specific guidelines have been developed not only for different categories of bacteria and fungi (e.g., members of the Enterobacteriaceae family) but also for individual species. Perhaps the most important guidelines published by CLSI are that antimicrobial agents should be tested against different microbial pathogens Dr.T.V.Rao MD

  27. Why All Diagnostic Laboratories should adhere to • The information used to develop these guidelines is based on clinical, pharmacologic, and microbiologic data. It is strongly recommended that clinical microbiology laboratories and providers both adhere to these guidelines; testing antimicrobial agent–pathogen combinations that are not recommended may generate antimicrobial susceptibility test results that either are misleading or cannot be interpreted. • In general, it is also strongly recommended that new antimicrobial agents should not be tested in clinical laboratories until there are sufficient data for CLSI guidelines to be developed and published Dr.T.V.Rao MD

  28. Reporting newer pattern of Resistance needs reference Methods • Detection of new types or patterns of antimicrobial resistance may be fortuitous or the result of active surveillance. The former should not be used to guide patient care until the data are confirmed by a reference method; published reports of new types or patterns of resistance typically reflect extensive confirmatory testing. Dr.T.V.Rao MD

  29. Follow current practices as per CLSI guidelines • Most microbiology laboratories use commercial systems for antimicrobial susceptibility testing, which may or may not yet have the capability of detecting newer forms of resistance, reliable means of detecting new types or patterns of antimicrobial resistance often lag behind published information. Dr.T.V.Rao MD

  30. Implementation of WHONET CAN HELP TO MONITOR RESISTANCE • Legacy computer systems, quality improvement teams, and strategies for optimizing antibiotic use have the potential to stabilize resistance and reduce costs by encouraging heterogeneous prescribing patterns and use of local susceptibility patterns to inform empiric treatment. Dr.T.V.Rao MD

  31. World Antibiotic Resistance Network • WHO has also started another program, WARN (the World Antibiotic Resistance Network), to help gather and analyse the data generated by the people who use WHONET. Dr.T.V.Rao MD

  32. Recent advancesDiagnostic Microbiology Are We Using It – How much we use them ? Dr.T.V.Rao MD

  33. Up gradation to Automation in Critical samples • Automated and semi automated systems have been available for some years but without full realization of their potential for rapid diagnosis. They fall into two main groups: identification and susceptibility testing instruments and blood culture systems. Whereas some identification and susceptibility testing instruments take as long as traditional methods, others provide results within a single working day. Dr.T.V.Rao MD

  34. Automation in Blood Culturing reduces mortality and Morbidity • Blood culture systems have had considerable impact on the ability to detect bacteremia. Growth is detected through generation of a radiometric signal or a fluorescent or colorimetric indicator. Most true posi­tive results are detected within 24 to 36 hours. Identifi­cation and susceptibility results may be obtained in many blood culture isolates within the same time when a blood culture system is combined with an automated identification or susceptibility testing instrument Dr.T.V.Rao MD

  35. Several Life threating conditions can the treated Promptly • Blood culture systems have been adapted for the automated or semi automated culture of Mycobacteriumtuberculosis and other mycobacteria. These commercial systems reduce the traditional dependence on bio­ chemical reactions to identify organisms; avoid the and mycobacteria among others. Nucleic acid amplifica­tion systems are available for the direct detection in clinical specimens of hepatitis C virus, HIV, M tuberculo­ sis, C trachomatis, and N gonorrhea since more than a decade. Dr.T.V.Rao MD

  36. Molecular techniques • Molecular biological techniques have increased the speed and sensitivity of detection methods, as well as allowing laboratories to identify organisms that do not grow or grow slowly in culture. These techniques also allow microbiologists to identify genes that result in resistance to antibiotics and to “fingerprint” individual isolates for epidemiological tracking. Dr.T.V.Rao MD

  37. New technologies enable to … • New technologies enable microbiology results to be available in minutes or hours rather than days. • Early diagnosis better prognosis and lesser costs in treatments Dr.T.V.Rao MD

  38. Molecular biological methods • Nucleic acid probe hybridization, the polymerase chain reaction, the ligase chain reaction, transcription medi­ated amplification, other evolving amplification meth­ods, and nucleic acid sequencing form the basis of detecting and characterizing an ever increasing range of viruses, bacteria, fungi, and protozoa Dr.T.V.Rao MD

  39. Immunoassays have benefits • Immunoassays have benefits of technical simplicity, rapidity, specificity, and cost effectiveness but often have poor sensitivity and low negative predictive value Dr.T.V.Rao MD

  40. Molecular Methods helps in New trends in… • Recognition of newly emerging infectious diseases and control of antibiotic resistance in Streptococcus pneumoniae, Haemophilus influenzaMorax­ella catarrhalis, Staphylococcus aureus, and Common Gram negative bacilli will rely heavily on these new technologies. Dr.T.V.Rao MD

  41. Limitations of Molecular Methods • The introduction of molecular diagnostic methods in the microbiologic diagnostic laboratory is subject to a number of practical and financial constraints requiring the elaboration of a sound strategy. Validation of the tests may require the use of an expanded gold standard or the application of novel statistical methods such as latent class analysis. Dr.T.V.Rao MD

  42. Limitations of Molecular Methods ? • The procedures should be constantly evaluated for false positive an false negative results. The introduction of molecular methods will not only depend on their performance for each individual microorganism, but also on the clinical relevance of the diagnostic question asked, the prevalence of the clinical problem and whether the new methods are added to the procedures in use or will replace them. Therefore no general rules can be proposed, strategies have to be elaborated for each infectious agent or clinical syndrome Dr.T.V.Rao MD

  43. Microbiologists must plan and Execute for change • With increase in availability of cost effective commercial systems, laboratories will be able to capitalize on the extreme specificity, high sensitivity, and rapidity of these molecular approaches. Dr.T.V.Rao MD

  44. Better Diagnosis in Emerging and Reemerging Infection • An ever increasing range of viruses, bacteria fungi, and protozoa can be detected and characterized by molecular biological methods Dr.T.V.Rao MD

  45. DO WE HAVE ANTIBIOTIC POLICY ?DO WE HAVE CONTROL OF ANTIBIOTIC USAGE ? Dr.T.V.Rao MD

  46. Misuse of Antibiotics Drives Antibiotic Resistance • Studies prove that misuse of antibiotics may cause patients to become colonized or infected with antibiotic-resistant bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE) and highly-resistant Gram-negative bacilli.13-14 • Misuse of antibiotics is also associated with an increased incidence of Clostridium difficile infections.15-17 Dr.T.V.Rao MD

  47. Spread of Antibiotic Resistance • Indiscrimate use of Antibiotics in Animals and Medical practice • R plasmids spread among co-inhabiting Bacterial flora in Animals ( in gut ) • R plasmids may be mainly evolved in Animals spread to Human commensal, - Escherichia coli followed by spread to more important human pathogens Eg Shigella spp. Dr.T.V.Rao MD

  48. What is Misuse of Antibiotics? Misuse of antibiotics can include any of the following • When antibiotics are prescribed unnecessarily; • When antibiotic administration is delayed in critically ill patients; • When broad-spectrum antibiotics are used too generously, or when narrow-spectrum antibiotics are used incorrectly; • When the dose of antibiotics is lower or higher than appropriate for the specific patient; • When the duration of antibiotic treatment is too short or too long; • When antibiotic treatment is not streamlined according to microbiological culture data results. Dr.T.V.Rao MD

  49. Aim of Antibiotic Policy • Reduce the Antimicrobial resistance • Initiate best efforts in the hospital area as many resistance Bacteria are generated in Hospital areas and in particular critical care areas. • Initiate good hygienic practices so these bacteria do not spread to others • Practice best efforts, these resistance strains do not spill into critically ill patients in the Hospital • To prevent spill into Society, as they present as community associated infections.. Dr.T.V.Rao MD

  50. Objectives of Antibiotic Policy. • Antibiotics should not be used casually • Policy emphasizes, avoiding the use of powerful Antibiotics in the Initial treatments. • We should create awareness that we are sparing the powerful Broad spectrum Drugs for later treatment Patient saves Money Doctors save Lives. Dr.T.V.Rao MD

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