Staphylococcal Infection

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Staphylococcal Infection. Bacteriology. Bacteriology. Gm +ve cocci Cluster Facultative Nonfastidious. Classification. Classification. Staph. Aureus; Coagulase positive Staph. Epidermidis; Coagulase negative. Staph. Aureus Infections. Mechanism of pathogenesis; - PowerPoint PPT Presentation

Text of Staphylococcal Infection

  • Staphylococcal Infection

  • Bacteriology

  • BacteriologyGm +ve cocciClusterFacultativeNonfastidious

  • Classification

  • ClassificationStaph. Aureus; Coagulase positive

    Staph. Epidermidis; Coagulase negative

  • Staph. Aureus InfectionsMechanism of pathogenesis; 1-coenzymes local destruction 2-Secretion of Toxins 3-Superantigens activating T cell receptors 4-Interfer with opsonophagocytosis

  • EpidemiologyNormal human flora; nose& moist areas

    Transmission; Hands/nose sec/contact/rarely air.Colonize; skin, newborn nasoph& umb.

    Invasion; Skin breaks, I/V access, immune defect, steroids and neutropenea.

  • Clinical conditions

  • Clinical conditionsSuppurative.

    Toxic related;

  • Clinical conditionsSuppurative.

    Toxic related; Scalded Skin Syndrome SSS Toxic Shock Syndrome ??Kawasaki Disease Food poisoning

  • SkinFoliculitis

    Furaculosis (Boils)/Carbunkles

    Emptigo contagoesa

    Bullous Emptigo

    SSS (Ritter disease)

  • Respiratory InfectionsSinusitis


    Cervical adenitis

    Tracheitis compared to croup


  • SepsisStart as focal lesion e.g. a boil

    Yield to septicemia

    Localize to organs e.g. lung, bone, heart, brain etc

  • Muscles/Bone/JointsTropical pyomyositis; Localized abscesses and high CPK

    Osteomylitis; Trauma/Sx, pain, fever

    Septic arthritis; Usually hematogenous

  • CNSMeningitis; Bacteremea, O.M, skull osteo., neural canal defects.

    Neurosurgical procedures and VP shunt

  • HeartBacterial endocarditis; -Perforated heart valve -myocardial abscess -purulent pericarditis -Sudden death

  • KidneyPerinephric abscess

    UTI; Staph. saprophyticus (CONS) Sexually active adolescent girls

  • G.I.Food poisoning; Meat, mayonnase, creamed foods Short incubation period of 1 to 7 HRs Perfuse vomiting, no fever Test susp. food for staph bacteria/ toxins

  • DiagnosisIsolate staph. bacteria

    Gram stain

    Identify Toxins

  • TreatmentPenicillinase resistant antibiotics; Oxacillin (Cloxacillin, Flucloxacillin) methicillin Nafcillin 1st generation cephalosporine, cefazolin (Ultracef)

  • Treatment cont.Betalacamase hyperprodcer staph.; Amoxicillin/Clavulenic acid(Augumentin) Ampicillin/Salbactam Imipenem Fluoroquinilones 1st generation cephalosporin Vancomycin

  • Coagulase negative Staph. (CONS)Common Skin FloraUbiquitous organismHas affinity to plastic (surface hydophobicity & production of slim)Neonates, I/V access and shunt devices infections (nosocomial infections)

  • Clinical ConditionsPremature neonatal sepsis/NEC.Older children sepsis is rare (minimal signs of sepsis)Persistent pactreamia usual with indwelling devices (I/V cath, VP shunt, cardiac grafts and prosthesis etc.)

  • Clinical Cond. Cont.Single positive blood culture is a contaminant

    UTI in adolescent girls Staphylococcus Saprophyticus (CONS)

  • TreatmentRemove the access devices/shunts.

    May externalize the VP shunt.

    Vancomycin or Rifampin.

    Amoxicillin or Quinolones for the Staph Saprophyticus UTI.

  • Nosocomial Infections

  • Definition Infections not present or incubating at the time of admission that develop during admission or less than one incubation period after discharge

  • Definition cont.Infections 48 HRs or more after admission is assumed to be nosocomial unless the infection is clearly community acquired

  • Clean Surgery

  • Clean Surgery Incision through prepared normal skin and the operative field dose not include infected tissue , abscess, or entry into normally unsterile areas such as the bowel, the upper respiratory tract, or the lower female genital tract.

  • Rate of Nosocomial Infections Number of nosocomial infections divided by the number of patients at risk multiplied by 100

  • Epidemiology1/3 hospital infections are nosocomial (estimate in the USA) i.e. 2 million patients i.e. 4 million patient days of hospitalization i.e. 4.5 Billion USD i.e. 17 Billion SAR

  • Epidemiology cont.In USA (1978) nosocomial inf. rate; -All services 3.37% -Pediatric services 1.2%

  • Epidemiology cont. Common sites of ped. nosocomial infections (as per the NNIS);Blood streamSurgical sitesLower respiratory tractUrinary tract

  • Epidemiology cont. In adults;

    Urinary tractSurgical sitesLower respiratory tractBlood stream

  • Epidemiology cont. Common PEDIATRIC nosocomial bacteria;Staphylococcus aureusEscherichia coliCONSKlebsiella

  • Epidemiology cont.Common NEONATAL nosocomial bacteria;CONSStaphylococcus aureusEscherichia coliGroup B sterptococciKlebsiella

  • Epidemiology cont.Areas of high nosocomial infection rates;NICUPICUBurn Units

  • Risk Factors of Nosocomial Inf.General risk factors;Prior colonization with nosocomially acquired bacteriaCathetersExposure to antibiotics

    Specific risk factorsInhalation equipmentsSpecific monitoring caths e.g. arterial cath etc.Viral infections

  • General risk factorsPrior colonization;Klebsiella colonization after admission gave 50% incidence of infectionInhalation therapy, N/G suction and antibiotics are behind the colonization

  • General risk factorsCatheters;Increase risk of septicemia with method of insertion, type of solution and duration of placement (I/V catheter)Major risk of septicemia in neonatesUrine catheter is a risk for UTI in females, elderly and critical pt.sRisk increase with method of insertion, length of tube and break of the system

  • General risk factorsExposure to Antibiotics;Prior use of broad spectrum antibioticsNormal flora protect the host through blocking the surface receptor/attachment sites

  • Specific risk facorsSpecial cathetersPressure trasducersArterial cathetersSwan-Ganz catheters

  • Specific risk facorsViral infectionsRSV close contact with infants at riskVaricella ( 8-21 days incubation) and risk for nonimmune and immune suppressed. Screen hospital personnelRota virus

  • Prevention and control of nosocomial infectionsGeneral measures;A team of infection control teamEnforce surveillance of equipments, disinfection and isolation techniques

  • Specific risk factorsInhalation equipmentsNebulizers and humidifiersRisk of necrotizing pneumoniaDecontamination with .25% acetic acid and ethylene oxide

  • Prevention and control of nosocomial infectionsUniversal precautions;Barrier precautions prevent exposureHand washProper handling of sharp instrumentsResuscitation equipmentsPersonnel with exudative lesionsPregnant health workers

  • Prevention and control of nosocomial infectionsIsolation techniques;Apply specific isolation to specific diseases

  • Prevention and control of nosocomial infectionsHand wash practice;Most effective and least expensive practice to prevent transmission of pathogensEducate personnel of the method of hand wash (15 seconds with warm water and soap then dry and turn faucet with towel)

  • Prevention and control of nosocomial infectionsIntravenous therapy;Hand washClean site with 70% alcohol and 10% providone-iodinePreferred locations in pediatrics are scalp, hands and footMinimize duration if possibleProphylactic antibiotics are not recommendedRemove catheter if sign of inflammation