microbiology of bone & joint infections
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Microbiology of Bone & Joint Infections. Myositis. Myositis refers to any condition causing inflammation in one or more muscles Weakness , swelling, and pain are the most common myositis symptoms Myositis causes include infection, injury, autoimmune conditions, and drug side effects - PowerPoint PPT PresentationTRANSCRIPT
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Microbiologyof Bone & Joint InfectionsMyositisMyositis refers to any condition causing inflammation in one or more muscles
Weakness, swelling, and pain are the most common myositis symptoms
Myositis causes include infection, injury, autoimmune conditions, and drug side effects
Treatment of myositis varies according to the causeCauses of MyositisMyositis is caused by any condition that leads to inflammation in the muscles
Myositis causes can be divided into several major categories:
Inflammatory conditions causing myositisMyositis caused by microbial infectionMyositis caused by drugsMyositis due to injuryMyositis caused by microbial infectionKnown pathogens include the following:
ViralHIV (one of the most common causes of myositis), HTLV-1, Cytomegalovirus, Coxsackie B virus (epidemic myalgia), Influenza
BacterialS. aureus (most common, 70%); Streptococcus viridans; Salmonella enteritidis; Neisseria species , Yersinia species
SpirochetalBorrelia burgdorferi
MycobacterialMycobacterium avium
ParasiticEchinococcus granulosus, Taenia solium, T. cruzi
FungalCryptococcus neoformans, Candidaspecies, Histoplasma capsulatum, Aspergillusspecies
Symptoms of MyositisThe main symptom of myositis is muscle weakness that may be detectable with testing
Muscle pain (myalgias)
Dermatomyositis, polymyositis
The weakness affects large muscle groupsincluding the neck, shoulders, hips, and back
DermatomyositisDermatomyositis (DM) is a connective-tissue disease related to polymyositis (PM) that is characterized by inflammation of the muscles and the skin6
DermatomyositisThe weakness from myositis can lead to fallsmake it difficult to get up from a chair or after a fall
Other myositis symptoms that may be present with inflammatory conditions include:
RashFatigueThickening of the skin on the handsDifficulty swallowingDifficulty breathingDiagnosis of MyositisBlood testsMagnetic resonance imaging (MRI scan)Electromyography (EMG)Muscle biopsy
9OsteomyelitisOsteomyelitis is an infection in a bone
Infections can reach a boneby traveling through thebloodstream or spreadingfrom nearby tissue
Osteomyelitis can also beginin the bone itself if an injuryexposes the bone to germs
Osteomyelitis of the tibia of a young childIn childrenmost commonly affects the long bones of the legs and upper arm
In adultsmore likely to develop osteomyelitis in the bones that make up the spine
People who have diabetesmay develop osteomyelitisin their feet if they have foot ulcers
Plantar foot ulcers with a deep space infectionOnce considered an incurable condition, osteomyelitis can be successfully treated today
Most people require surgery to remove parts of the bone that have diedfollowed by strong antibioticsoften delivered intravenouslytypically for at least six weeksSymptomsSigns and symptoms of osteomyelitis include:
Fever or chillsIrritability or lethargy in young childrenPain in the area of the infectionSwelling, warmth and redness over the area of the infectionCausesMost cases of osteomyelitis are caused by staphylococcus bacteria
Germs can enter a bone in a variety of ways, including:Via the bloodstreamFrom a nearby infectionDirect contaminationVia the bloodstreamGerms in other parts of the body can travel through bloodstream to a weakened spot in a bone
From a nearby infectionSevere puncture wounds can carry germs deep inside the bodyIf such an injury becomes infected, the germs can spread into a nearby bone
Direct contamination
This may occur if a bone have broken so severely that part of it is sticking out through skin
Direct contamination can also occur during surgeries to replace joints or repair fractures16Disease causative agentAge groupMost common organismsNewborns(younger than 4 mo)S. aureus,Enterobacterspecies, andgroup AandB StreptococcusspeciesChildren (aged 4 mo to 4 y)S. aureus, group AStreptococcusspecies,Haemophilus influenzae, andEnterobacterspeciesChildren, adolescents (aged 4 y to adult)S. aureus(80%), group AStreptococcusspecies,H. influenzae, andEnterobacterspeciesAdultS. aureusand occasionallyEnterobacterorStreptococcus speciesSickle cell anemia patientsSalmonellaspecies are more common in patients with sickle cell disease than in normal patients. However, S. aureus is still most likely to occur.Acute Osteomyelitis Vertebral osteomyelitis can occur in adults secondary to a UTI or prostatitis
Candidemia from infected central venous catheters can lead to fungal osteomyelitis
Contiguous infectionBacteria related to primary focus, it includesGram positive cocci, Gram negative bacilli, Anaerobes, and Poly-microbial infection
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Risk factorsBones are normally resistant to infectionFor osteomyelitis to occur, a situation that makes your bones vulnerable must be present
Recent injury or orthopedic surgeryA severe bone fracture or a deep puncture woundSurgeryDeep animal bites19Circulation disordersWhen blood vessels are damaged or blockedWhat begins as a small cut can progress to a deep ulcer that may expose deep tissue and bone to infection
Diseases that impair blood circulation includePoorly controlled diabetesPeripheral arterial diseaseoften related to smokingSickle cell disease
Peripheral vascular diseaseProblems requiring intravenous lines or catheters
Examples of when this type of tubing might be used includeDialysis machinesUrinary cathetersLong-term intravenous tubing21Conditions that impair the immune system
Factors that may suppress your immune system includeChemotherapyPoorly controlled diabetesHaving had an organ transplantNeeding to take corticosteroidsFor unclear reasonspeople with HIV/AIDS don't seem to have an increased risk of osteomyelitis
Illicit drugsnonsterile needlesunsterilized skin before injections
ComplicationsOsteomyelitis complications may include:
Bone death (osteonecrosis)Septic arthritisImpaired growthSkin cancer
OsteonecrosisTests and diagnosisBlood testsImaging testsX-raysComputerized tomography (CT) scanMagnetic resonance imaging (MRI)Bone biopsy
Treatments and drugsThe most common treatments for osteomyelitis are antibiotics and surgery to remove portions of bone that are infected or deadHospitalization is usually necessary
Medications
A bone biopsy will reveal what type of germ is causing the infection
The antibiotics are usually administered through a vein for at least four to six weeks
Side effects may include nausea, vomiting and diarrhea
An additional course of oral antibiotics may also be needed for more-serious infectionsSurgery
Depending on the severity of the infection, osteomyelitis surgery may include one or more of the following procedures
Drain the infected areaRemove diseased bone and tissueRemove any foreign objectsAmputate the limbArthritisInfectious Arthritis is inflammation of the joint space
Generally affects a single jointand result insuppurative inflammation
Hematogenous seedingof joint is most common
Pain, swelling, limitation of movement common symptoms
Etiology, Epidemiology & Risk factorsGonococcal infection most common cause in young adults caused by Neisseria gonorrheae
Nongonococcal arthritis occurs in older adults
Occasionally results from direct trauma, procedures (arthroscopy) or from contiguous soft tissue infection
S. aureus is most common causeOther organisms : streptococci and aerobic Gram negative bacilli
Lyme disease in endemic areas
Risk factors: age, diabetes, immunosuppression, IV drug use, catheters, prior joint damage, sexually transmitted diseasesDiagnosis of Infectious ArthritisHistory/examination to exclude systemic illness
Blood culturesculture or DNA testing for N. gonorrheae
Urine may be used for DNA testing also
Culture of joint fluid, and skin lesions also indicated
Treatment & ManagementArthrocentesis with drainage of infected synovial fluid
Repeated therapeutic arthrocentesis often needed
Occassionally, arthroscopic or surgical drainage/debridement
Antimicrobial therapy should be directed at suspected and susceptibility resultsGonococcal arthritis: IV Ceftriaxone ( or Ciprofloxacin or Ofloxacin) then switch to oral Quinolone or Cefixime for 7-10 days
Nongonococcal infectiuos arthritis
MSSA: Nafcillin or Cefazolin.
MRSA: Vancomycin
Streptococci: Penicillin or Ceftriaxone or Cefazolin
Enterobacetriacae: Ceftriaxone or Fluroquinolone
Pesudomonas: Piperacillin and Aminoglycoside
Animal bite : Ampicillin-Sulbactam
Lyme disease arthritis: Doxycycline for 1 month
Prognosis & ComplicationsGonococcal arthritis has an excellent outcome
Nongonococcal arthritiscan result in scarring with limitation of movement, ambulation is affected in 50% of cases
Risk factors for longterm adverse sequellae include
Age, prior rheumatoid arthritis, poly-articular joint involvement, hip or shoulder involvement, virulent pathogens and delayed initiation or response to therapy
Acne vulgarisAcne vulgaris (cystic acne or simply acne)
A common human skin diseasecharacterized by areas ofscaly red skin, blackheadsand whiteheads,and possibly scarring
Acne affects mostly skinwith the densest populationof sebaceous folliclesthe face, the upper part of thechest, and the backSigns and symptomsScars Pigmentation
CauseHormonalGeneticPsychologicalInfectiousDiet
Different types of Acne Vulgaris: A: Cystic acne on the face, B: Subsiding tropical acne of trunk, C: Extensive acne on chest and shoulders.Infectious AgentPropionibacterium acnes (P. acnes) is the anaerobic bacterium species that is widely concluded to cause acne
Staphylococcus epidermidis has been universally discovered to play some role in acne formationMedications Benzoyl peroxideAntisepticsAntibioticsHormonesTopical retinoidsOral retinoidsAnti-inflammatories
Benzoyl peroxide cream