TRACING THE CRIMINAL Part twelve: Cooperation at investigation or Clinical Microbiology I Institute for microbiology shows L TRACING THE CRIMINAL Part thirteen: Cooperation at searching, or Clinical microbiology II Institute of Microbiology shows L Introduction (material comes on Christmass, tooJ) P1010009 Foto O. Z. Survey of topics [USEMAP] Introduction to clinical microbiology 1 Indication 2 Sampling + 3 Transportation 2A Sampling: Blood cultures 2B Sampling: Urine samples 2C Sampling: Other examples 4 Decision how to process 5 Proper processing 4A Processing and „reading“ in respiratory specimens 4B Processing and „reading“ in wounds & urine spec. 6 Result sending 7 Interpretation Introduction to clinical microbiology Story One – 1 nPeter was coughing all the time, so he visited a doctor. The doctor wanted to perscribe antibiotics directly, but then he remembered, that microbiologists told him to perform examinations. So he performed a throat swab. In the swab, Haemophilus influenzae was found, susceptible to cefuroxim. Peter started to used ZINNAT (a drug that contains cefuroxim). Story One – 2 nPeter, though, was no better. He became angry and visited a doctor on a pulmonary clinic. Here, serology of respiratory viruses was performed and high titers of antibodies against Mycoplasma pneumoniae found. Peter started to use SUMAMED (Azithromycin) and soon his status became much better. The problem was caused not only by Mycoplasma pneumoniae, but nalso by GP X. Y., because: nhe was right in remembering, that it is mostly usefull to know the pathogen and antibiotic susceptibility before treatment nnevertheless, he made a mistake in decision what microbiological method is indicated in this case na specimen of sputum had to be sent, and at negativity of culture (or at indicia showing rather an atypical pneumonia than a classic one) eventually clotted blood for serology of respiratory viruses (this examination contains also some non-viral agens, namely Mycoplasma and Chlamydia) nRemark, that sometimes macrolides are the good solution (although usually I am rather fighter agaist their abuse) Story Two nNicol felt sore throat, and so she visited a doctor. Throat swab was performed, but only common flora was found. Doctor was surprised, elevated polymorphonuclears and CRP showed that it should be a bacterial pyogene infection. nDoctor knew Nicol and knew that she had more sexual partners. After a direct question, she admitted that she had performed oral sex with a risky partner. A new swab was performed, now with notice „gonorrhoea examination“. And he was not mistaken. Who was guilty? Only Neisseria gonorrhoeae nGeneral practitioner worked very good; gonococcal pharyngitis is not so common that it would be routinelly examinated. But he was good, that he found it after the primary negative examination. nDoctor was clever – he knew that each specimen type has its routine laboratory schedule. This schedule is used always when there are no special requests. Special requests should be written on laboratory request. Clinical microbiology – what is it? nClinical microbiology „sensu lato“ is medical microbiology – so the part of microbiology, that describes microbial flora of human and human pathogens nClinical microbiology „sensu stricto“ describes proper processes betheen clinical workplace and the laboratory, including organisation of proper laboratory examination Process of clinical examination – everything matters!!! CLINICIAN LABORATORY Indication: to do it? what type? Proper sampling of material Material transport Decision how to elaborate Proper material elaboration Result sending Interpretation in context of other results and patient status (to treat patient, not lab finding) P 12 P 13 [USEMAP] 1 Indication 1A Indication – WHETHER to do anything nThe main key to success is to ask how will be my action changed in relation with examination result. nWhen i see that not regarding the result my further relation to the patient will be the same, the examination is probably useless nThis is not valid in epidemiologic indications and in prophylactic indications (like screening of microbial colonisation in serious patients) 1B Indication – WHAT to do nDecision that „I want to perform an examination“ is not the end of everything. I have to think about what examination should be done. nI have to know pathogens spectre and methods of their examination nOne part of that is also decission about how to perfom sampling technically (including: what vessel or sampling kit should be used) Three types of pathogens (1) nPathogen type Streptococcus pyogenes. It is not necessary to know that I mean just THIS pathogen, but I have to know pretty well where it is supposed to be localised (throat, lungs…) nPathogen type Mycobacterium tuberculosis. I have to know where the pathogen is localised, but also to know what group of pathogen is searched – so I have to write it to the request form nPathogen type Toxoplasma gondii. It is not necessary to know where in the body the pathogen is placed, but I have to know that I search for THIS pathogen. Three types of pathogens(2) nPathogen type Streptococcus pyogenes. Bacteria and yeasts that can be cultivated, so majority of microbes from P01 to P06 and partially also P10 nPathogen type Mycobacterium tuberculosis. It is still direct diagnosis, but special methods, the agent cannot be caught at normal culture. Mostly microbes from P07, P08, J13, part of P06 (gonorrhoea). nPathogen type Toxoplasma gondii. Indirect diagnostics, eventually direct diagnostics of viral antigen. Spirochets of P09, viruses from J11 + J12, but also many others (for example just Toxoplasma) Odbě1 [USEMAP] www.medmicro.info 2 Sampling (including order form) 3 Transportation 2 Proper sampling 3 Sample transport to the laboratory nThese phases cannot be divided – sampling should be performed with regard to material transport to the laboratory nThere are three types of samples: nCotton swabs on a plastic stick or wire nLiquid and solid specimens sent in vessels (mostly sterile vessels) nOther and special cases, see later nProper filling of the request, sent together with the sample, is very important too! Swabs F:\Documents\Klinika\13 opticsplanet_1979_559317030.jpg www.opticsplanet.com Other types of material than „swabs“ and „vessels“ nsmear on a slide: gonorrhoea, actinomycosis, directly sent thick drop and thin smear etc. nin dermatology and epidemiology just the culture medium that is filled to the margin of the dish; in surgery moulage with a filtration paper nuricult – special way of urine sending just cultured on a medium; for many reasons, it is not very common. nquick diagnostic sets, mostly based on direct antigen detection; simple manipulation, available even for non-microbiological personel. In case of doubts about the result it is necessary to use classical sending to the lab. Election: How to sample? Liquid sample, or swab? lUsually, sending solid/liquid sample is preferred in comparison with sending swab lThough, there are many exceptions, e. g. •in bacteriology usually rectal swab is sent and not stool (although it is not a mistake to send stool) •urethral swab in gonorrhoea is recommended rather than urine sending Contact plate F:\Documents\Klinika\09 kontaktní destičky.jpg www.dunnlab.de Uricult F:\Documents\Klinika\20 Uricult.jpg www.mediost.com Some types of swabs F:\Documents\Klinika\11 Abstrichbesteck-MEDI_SWAB.jpg Amies medium with charcoal www.herenz.de Universal transport medium for bacteriology (all types of swabs). The wire variant important, if we want to go „behind the corner“ Plain (dry) swab www.calgarylabservices.com Today its use is for PCR and antigene detection only, not for culture! F:\Documents\Klinika\12 PlainSwab.gif More swabs F:\Documents\Klinika\17 virus swab.jpg Virus swab www.copanswabs.com F:\Documents\Klinika\18 chlamydia swab.jpg Chlamydia swab www.copanswabs.com Fungi Quick (for yeast and molds) www.copanswabs.com C. A. T. swab (for Candida And Trichomonas, from genitals only www.copanswabs.com P1010011čb P1010011čb Survey of swabs Dry swab on a stick: search for antigen and DNA Dry swab on a wire: the same, if I need to get to an inaccessible place Swab in Amies medium on a stick: universal for bakteriological culture (incl. anaerobes, gonorrhoea, campylob.) Swab in Amies medium on a wire: the same, if I need to get to an inaccessible place Fungiquick – fungi C. A. T. – fungi and trichomonas (genital swabs) Samples with medium for viruses, event. chlamydiae Vessels nSampling vessels are used for solid and liquid samples. In fact, size is not so important, also colour of the cap has no real importance. Nevertheless, sometimes laboratory wants e. g. yellow cap for urine, red cap for blood (to simplify sample classification); if so, it is necessary to accept it nIn anaerobic culture it is better to send just a syginge with needle sticked into a sterile rubber cap nSpecimens should be transported to the laboratory as soon as possible, but the most important situation is in urine sampling; here, 2 h is maximum transport time! Vessels Zkumavka sérová čb otočená bez popisu Sputovka čb otočená bez popisu Na střevní parazity čb otočený bez popisu Do toho se vychčije čb Common test tube. Universal use: clotted blood (serology), urine, CSF, pus, punctate etc.; blood and urinary cathethers, parts of tisue… Sputum vessel. Not only for sputum, but also larger parts of tissue etc. Stool vessel, for parasitology. Only this one does not have to be sterile! Vessel for urine sampling. It is better, if the patient urinates just into a test-tube, but especially for women this is difficult (except if they are in shower). So they can urinate into this vessel, and then a nurse removes the urine into a test-tube. Various vessels F:\Documents\Klinika\08 další odběrovky.jpg w.dunnlab.de nProperly filled order form is very important! nIdentification data: for identification, payment, for knowing, whom to send the result etc. nPrecise description ot material and requested examination ndo not write only „swab“ without adding more neven „wound swab“ is not enough (what type of whound, where is its localisation) nCathetrized urine × urine from permanent catheter nwrite, whether e. g. anaerobes are requested nnot to request examination that is not available or is useless (e. g. cultivation examination of syphilis) Order form 1 Order form 2 – what to write in nreal diagnosis, in case of more diagnoses, write all of them, or the one realated with examination /e. g. (1) diabetes mellitus, (2) vaginal discharge/ nacute / chronical status / control after treatment nto add present or planned antibiotic therapy, eventually allergy to antibiotics Order form 3 – what to add more ntraveller anamnesis – tropical countries etc. nprofessional anamnesis – job in agriculture etc. nin serological examination date of first symptomas, first / second specimen nin gynecological materials phase of menstruation cycle (and rather not to sample during menses) nin case of irregular samples to consult it telephonically Order form filling – conclusion nWe should not forget to fill in all important parts of the order form: nfields describing the patient (name, date of birth/birth number, insurance, ward, diagnosis…) nfields describing the sample (type of specimen, localisation, important circumstances) nand all other important parts (especially anamnesis) Mistakes in order form filling nA common type of mistake is an insufficient description of sample type nIt is also bad to order examinations that are not suitable for the given situation (for example, search for antibodies in a pathogen, where cellullar immunity is leading and antibody search does not have any importance) [USEMAP] 2A Sampling: blood cultures Basic terms concerning septicaemiae nSepsis/septicaemia is a status, where bacteria caused bloodstream infection with fever, metabolic failure and other clinical symptoms nBacter(i)aemia is any presence of bacteria in blood, even a transitory one, that has no meaning for the organism nPseudobacter(i)aemia is a situation, when bacteria only seem to be present in blood (badly performed blood examination, usually skin contamination). Types of septicaemia nPrimary sepsis – some bacteria do sepsis „normally“, e. g. typhoid fever salmonellae or partially also meningococci nSecondary sepsis – sepsis coming after failure of an organ nSpecial types of sepsis nurosepsis – sepsis in kidney failure ncatether sepsis as hospital disease Sepsis – clinical picture ninstable body temperature ndecreased muscle tonus nintolerance of food, diarrhoea nrespiratory problems – frequent, irregular breathing, breath pause, failure nblood circulation problems – pulse more or less frequent, blood pressure decrease ncommon icterus, hyper/hypoglykaemia, metabolic failure, bleeding, neural symptoms etc. Definition of a blood culture nIt means not clotted blood, principially very different from serological examinations nToday we usually sample into special vessels for automatic culture nWe need to take two, but better three blood cultures at rise of temparature nIdeal is to use a new punction every time, or at least one venepunction + central venous catheter + peripherial venous catheter (bacteriaemia × colonisation of entry) How to take blood nTo work aseptically! Not only because of the patient, but also because of the sample. It is not sufficient to clean skin by petrol, it is necessary to perfom really disinfection. nThe disinfection should be let to act long enough, in alcohol agents to drying (to let the disinfectant really dry) nThe best is to use 3 blood culture vessels of the same type. Eventually to add e. g. one anaerobic nTo fill the order form, not forgeting the time of taking blood and site of sampling (CVK/peripherial catether/venepunction) Types of culture vessels nThere are various types regarding to microbes that are to be detected (aerobes, anaerobes) nSome vessels („FAN“) include charcoal. They are designed for culturing blood of patients already treated by antibiotics (classical vessel could give a false negative result – the antibiotic would suppress the growth) Kultivační flaštičky www.medmicro.info Standard aerobic Charcoal anaerobic Charcoal aerobic Function of cultivators nCultivator, connected to a computer, keeps automatically optimal conditions of cultivation, and also evaluates status of the vessel and indiacates eventual growth (e. g. change of CO2 tension) nThe growth is signalized optically and by a sound. When nothing is growing even afer a week, the apparate signalizes it too (it is time to give out a negative result) Odbě4 Odbě5 www.medmicro.info When a blood culture is positive… nThe vessel is brought from the apparate nIt is necessary to mark the time, or period from admission to positivity (more on the next slide) nWe perform inoculation to solid media, Gram stained smear and according to its result „directly“ orientation disc test of susceptibility; instead of standard suspension just fluid from vessel is used à the result is unsure Why it is so important to write the timing of sampling nExample 1: Three blood cultures taken, all of them positive, but one after 12 hours, another after 36 hours and the third after 3 days. The strains are phenotypically different à it is very likely that those are skin contaminants nExample 2: Three blood cultures taken, all of them positive, all of them after about the same time after sampling, strains look like the same à it is likely that it is a true pathogen E. coli in blood culture, phase contrast 04 E coli fázový konstrast http://www.visualsunlimited.com/browse/vu198/vu19873.html What to do after that nWe have to count that direct tests are only orientation tests, for not standard content of bacteria in individual blood samples. Usually in another step we perform proper susceptibility testing (often using quantitative tests) nExceptions are likely contaminations (especially in coagulase negative staphylococci) Cooperation laboratory – ward nLaboratory tries to coopetate with clinicians already during blood culture, mostly in form of telefonic report, sending preliminary results (even in negative blood cultures) etc. nAlso long term evidence of positive findings is usefull in frame of a systematic surveillance of hospital infections nDetails of cooperation should be mediated individually [USEMAP] 2B Sampling: urine samples Urine examination (Part One) nUrine examination is recommended in non-complicated and necessary in complicated cystitis: true nMicrobiologists recommend use of cathetrized urine as a routine way of sampling urine for bacteriology: false, normally taken urine is usually sufficient, but it should be sambled properly nIt is not important, whether prepuce (in men) or labia minora (in women) is in the way of urine stream when sampling urine for bacteriology: false, we should avoid contamination as much as possible Urine examination (Part Two) nExternal orifice of urethra should be carefully washed and eventually also disinfected before taking sampling urine for bacteriology true nThe vessel, that the patient urinates in, should be sterile true (and important!) nThe test tube used for urine transporation to the laboratory should have yellow cap false, it depends on individual organization nThe order form should contain information whether urine is „routinelly taken“, cathetrized, punctated, or whether it is a specimen taken from a permanent catheter true [USEMAP] Urine examination (Part Three) nUrine from permanent catether has the same value for bacteriological diagnostics as cathetrized urine (just for examination) false (urine from permanent cathether is worse, cathetrized urine is better than "normal" urine) nUrine specimen should be delivered to the laboratory in 2 hours after sampling, in impossible, it should be kept in refrigeratior true nUrine sample is better than urethral swab in gonorrhoea diagnostics false 2C Sampling: more examples Stool sampling nBacteria – in Amies transport medium nYeasts – the same, but better in FungiQuick medium nViruses (isolation) – sample sized like a hazelnut; when viral isolation is to be performed, it is necessary to send it at 0 °C nViruses (antigen) – sample sized like a hazelnut; no influence of the temperature nParasites – again hazelnut sized, not necesarilly sterile. Mark travellor anamnesis! Usually three specimens. nPinworms – Graham method – perianal imprint on special sticky tape, to be microscopied nClostridium difficile toxin – as for parasitology Moulage method in flat wounds nThis method is used to better quantify microorganisms, especially in wounds. Using square filtration papers, we can better differenciate between a real pathogen and an accidentally found contaminant nYou will use this method not for wounds, you will only try it to your own skin. Smears – Vaginal/urethral smear nSmears are usefull for actinomycosis, anaerobes, etc. Smears are also often used together with vaginal swabs. nTwo slides are sent. nOne is Gram stained (for examination of bacteria, yeasts, but also epithelial cells and WBCs) nThe second smear is Giemsa stained (mostly because of Trichomonas) nWe evaluate both quantity of individual objects and entire aprearance of the preparation nIn case of suspicion for gonorrhoea, urethral swabs are taken. We see white blood cells and intracellular diplococci. 02 N_b_ink_en http://en.microdigitalworld.ru Giemsa Normal picture: epithelial cells, lactobacilli (Döderlein bacillus) Vaginóza www.medmicro.info Picture of bacterial vaginosis (lactobacilli replaced by gardnerellae, event. mobilunci and other bacteria, common clue cells – bacteria adhered on epitheliae) Gram sputumgpko http://en.microdigitalworld.ru Aerobic vaginitis (unlike vaginosis, here leucotytes are present) Gram 06 man_gn7_b_Gr http://en.microdigitalworld.ru Gram Gonorrhoea 04 Trichomonas%20vaginalis1 http://medschool.sums.ac.ir Giemsa Trichomonosis 04 gr_5_b_ink_en http://en.microdigitalworld.ru Giemsa Vaginal mycosis [USEMAP] 4 Decision how to process 5 Proper processing 4 Decision, how to process the specimen nIt is described in operation standards (OS). For each sample type the OS says, what methods should be used for it, and what methods should be applied. nNevertheless, everything is not in OS. Especially in extraordinary cases it is on decision of experienced microbiologist, how to process the specimen nIn important cases is no mistake to phone to the laboratory and ask for an advice. 5 Proper specimen processing (1) nProper processing is usually done by laboratory asistants, formerly with secondary education, today with bachelor‘s degree or equivalnt Desf1 nThe procedure should be asseptical, to avoid risk of laboratory contamination. Work in a biohazard box je is also a good prevention of hospital infections www.medmicro.info 5 Proper specimen processing (2) nProcessing of bacteriological specimens usually contains following: nbefore proper processing, some specimens are homogenized, centrifuged etc. nin some specimen types quick methods – microscopy, eventually direct antigen examin. nnearly always it is based on culture on several solid media nsometimes also multiplication in liquid media (in conjunctival swab: ONLY this point) nProcessing of other specimens (serology, PCR, mycology, parasitology) is special and related with examination type and specimen type Klin5 Microbiologist „reads the laboratory“ – observes the results of the culture Assistant 1 writes the results Assistant 2 „does repeatings“: in positive specimens susceptibility test and identification tests are prepared www.medmicro.info Laboratory of clinical bacteriology What may a pathogen be confused with nWith a contaminant: mostly bacteria of genera Bacillus, Micrococcus, Kocuria, but also small amounts of staphylococci, fungi etc. nWith an accidental finding: in throat swabs a microb that came there with food nWith common flora: only in sites, where some normal microflora is present Survey of common flora Skin, nose, external ear, skin andexa Staphylococci (incl. Staph. aureus), coryneforms, yeasts Pharynx & oral cavity Oral streptococci and neisseriae. Hemophili, small amonunts of pneumococci, meningococci, anaerobes, non patogenous treponema Large (and small) bowel Anaerobes, enterobacteria, enterococci, Entamoeba coli Vagina Lactobacilli, small amounts of other bacteria Margins (lips etc.) Mixture from both sides [USEMAP] 4A Processing and „reading“ in respiratory specimens How to find a pathogen among common oropharyngeal flora nNormal flora consists of greyish, viridating colonies (oral streptococci) and yellowish, usually a-haemolytical colonies (oral neisseriae). They use to make a dense „carpet“ on the surface of agar medium and they make search for pathogens quite difficult, nevrtheless possible: nHaemolytic streptococci (and also Staphylococcus aureus) are visible by a strong haemolysis on blood agar nFor haemophili detection we use antibiotic disc with bacitracine – higher concentrations than in bacitracine test (to decline the normal microflora) nFor meningococcal detection we use another disk, with mixture of vancomycin and colistine Detection of pathogen in throat/sputum 1 swab inoculation 2 loop inoculation 3 staphylococcus line 4 bacitracin disc (for hemophili) 5 V + K disc (colistine and vancomycine) for meningococci In all parts of inoculated area we search for colonies with haemolysis. They could be streptococci (rather colourless) or goldish) Očkování krku 3 inverzní Cultivation result of throat swab with common flora Klin7 Klin9a In these sites we search for haemophili www.medmicro.info The bacitracin disk may be placed either on the Staphylococcus line, or approx. 1 cm far from it, both ways are used. Explanations to following screens nBA – blood agar nEA – Endo agar; usually, McConkey agar may be used as an alternative nBA+AMIK – blood agar with amikacin, selective for streptococci a enterococci nNaCl – BA with 10 % NaCl, selective for stafylococci nB – broth nURI – urichrome, a chromogenic medium for the most important pahtogens from urine 01 sputum1 Sputum examination www.lumen.luc.edu Sputum examination Diagnostic schedule (1) nDay 0: microscopy (Gram staining) nDay 1: result of primary culture on BA, EA and NaCl. If only common flora is present, EA is discarded and BA and NaCl is prolonged to another day. An eventual pathogen is identified and its antimicrobial susceptibility assessed. If there is a small amout of a pathgen, isolation is performaed (colony is carefully picked by a loop and reinoculated to a new agar plate to obtain a pure culture) Sputum examination Diagnostic schedule (2) nDay 2: expedition of negative results (observation of prolonged BA cultivation). Expedition of majority of positive results, if identification is finished antibiotic test result is OK. If not (too many resistances, more atb needed), or if only isolation is done, it is necessary to continue. nDay 3: expedition of majority of remaining positive results (resistant, difficult detection…) nDay 4: extraordinarilly expedition of remaining resultes (combination of several problems) Sputum – possible findings nCommon flora: There is no flora in LRW, but always a contamination from URW is present: oral streptococci and neisseriae nPathogens: pneumococci, pyogenous streptococci, haemophili (typical pneumoniae). Causative agents of atypic pneumoniae are moslty non-culturable. If you would find Staphylococcus aureus, you can use treatment using oxacilin, eventually, if oral oxacillin would not be available, to use Ist generation cephalosporins. Practical note nSmall, greyish, nearly colourless, viridating, are oral streptococci. nSmall, yellowish, without viridation, without haemolysis (or a slight partial haemolysis), oxidase positive are oral neisseriae nIf there is something more on our plate, and especially if this „something“ has a strong haemolysis, it is probably the expected pathogen. „Reading“ of bacteriology Klin4 www.medmicro.info 02 Throat_swab_P7251230 Throat swab biology.clc.uc.edu Throat swab Diagnostic schedule nDay 0: only start of the cultures nDay 1: result of primary culture of specimen on BA and EA. NaCl is not used here. Here, too, BA cultures with common flora are prolonged nDay 2: expedition of all negative and majority positive results nDay 3: expedition of mostly all remaining results Pharynx – possible findings nCommon flora: Oral streptococci a neisseriae; haemophili (mostly H. parainfluenzae), but normal are also small amounts of S. aureus, pneumococci, meningococci, moraxellae etc. More components of common flora (anaerobes, spirochets) are not found in normal culture nPathogens: pyogenous streptococci, arcanobakteria; often nothing is found and it is viral origin (EB viruses and others) nTreatment: In case of Streptococcus pyogenes found to be a pathogen, V-penicillin is used. Stre1 [USEMAP] www.medmicro.info 4B Processing and „reading“ in wound and urine specimens 03 wound%20close-up%202 Wound swab www.kinseyracingschool.com Wound swab Basic diagnostic schedule n(Different in different types of wound etc.) nDay 0: start of culture only nDay 1: result of primary culture of specimen on BA, EA, NaCl and BA+AMI. If all solid media are negative, B is observed; if turbid, a subcultivation to solid media is performed nDay 2: expedition of negative and some positive results; too resistant bacteria à more tests nDays 3, 4: expedition of remaining results Wound swab nCommon flora: none, all findings are looked as pathogen (we test even microbes suspicious of being contamination – better treat a contamination than not treat a pathogen) nPathogens: wide spectrum of bacteria, from staphylococci through streptococci and pseudomonads to anaerobes in abdominal wounds and pasterurellae in wounds after being bitten by a dog. It is recomended not to use antibiotic before atb susceptibility result. nRecommendation for treatment: e. g. ciprofloxacin in our case; but local care of the wound is more important than antibiotics! Urine 04 urine http://i96.photobucket.com Urine Basic diagnostic schedule nDay 0: start of culture only nDay 1: result of primary culture of specimen on BA, EA/URI, expedition of all negative results, pathogen testing nDay 2: expedition of positive results, if bacterial susceptibility is sufficient (if not, à more tests) nDay 3: expedition of remaining results Urine nThere is no common flora, nevertheless, in elderly often asymptomatic bacteriuria, it is not necessary to treat it nAs likely contamination (or accidental finding) is counted everything below 104 / ml, everything below 105 / ml in finding of two various bacteria and everything in three/more bacterial strains nAmong pathogens, the most common are enterobacteria, enterococci, S. agalactiae, staphylococci etc. Semiquantitative processing nA plastic loop is used – the „eye“ of the loop catches always 1 µl of urine nThis microliter is inoculated to one halfth of blood agar plate (you have it on a total plate) nFurther we inoculate Endo agar or URIchrom, here we assess it only qualitativelly nOf course, besides quantity examination we also examine genus and species of the bacterium as usually nIn our case, we would recommend nitrofurantoin for treatment. Semiquantitative urine evaluation Number of colonies Number of CFU (bacteria) in 1 µl of urine Number of CFU (bacteria) in 1 ml of urine Evaluation (valid for 1 bacterium) Less than 10 Less than 10 Less than 104 Contamination 10–100 10–100 104–105 Borderline More than 100 More than 100 More than 105 Infection [USEMAP] 6 Result sending 7 Interpretation 6 Result sending nResult is sent after finishing of the diagnostic process. Sometimes a preliminary result is sent after finishing the basic aerobic culture, and the remaining part (yeast culture, anaerobic culture etc.) is sent later nResult contains a partial interpretation: a microbiologist comments clear contaminations, accident findings, common flora, comments the findings in a note 7 Interpretation nDefinitive interpretation of finding should be done by the clinician. Only the clinician, not the microbiologist, has the microbiology result together with the biochemical, rtg, ultrasound result. And only he has done the anamnesis and clinical examination of the pacient. nOf course, consultation of a clinician and a microbiologist is very useful in serious cases. On the other hand, it is not possible to consult each case. A picture of laboratory Klin2 www.medmicro.info The End F:\Documents\Klinika\15 swabs.jpg [USEMAP] www.pathology.leedsth.nhs.uk