A boy presented with multiple non-suppurative osteomyelitic dactylitis with sickle cell anaemia. What will be the causative organism?
Correct Answer: Salmonella typhi
Description: (A) Salmonella typhi[?]Salmonella Osteomyelitis:Sub-acute form; Curiously, patients with sickle-cell disease are prone to infection by Salmonella typhi.More commonly in children with sickle cell anaemia.Occurs during the convalescent phase after an attack of typhoid fever.Multiple bones are affected bilaterally symmetrical.Radiologically- diaphyseal sclerosis # Causative bacteria:Staphylococcus aureus: the most commonStaph, aureus - expression of surface proteins that allow adhesion to bone matrix.E. coli and group B. strept - important causes of acute osteomyelitis in neonatesSalmonella - especially in patients with sickle cell disease.Mixed bacterial infections (e.g. anaerobes) - osteomyelitis secondary to bone trauma.50% of osteomyelitis cases - no organisms can be isolated.FOLLOWING ARE THE VARIOUS MICRO -ORGANISM INVOLVED IN OSTEOMYELITISAge groupMost common organismsNewborns (younger than 4 months)S. aureus, Enterobacter species, and group A and B Streptococcus speciesChildren (aged 4 months to 4 year)S. aureus, group A Streptococcus species, Haemophilus influenzae, and Enterobacter speciesChildren, adolescents (aged 4 year to adult)S. aureus (80%), group A Streptococcus species, H. influenzae, and Enterobacter speciesAdultS. aureus & occasionally Enterobacter or Streptococcus speciesSickle cell anemia patientsSalmonella species are most common in patients with sickle cell diseaseOther Options[?]Acute haematogenous osteomyelitis causative organisms:Acute haematogenous osteomyelitis is mainly a disease of children.[?]Staphylococcus aureus:The causal organism in both adults and children is usually Staphylococcus aureus (found in over 70% of cases), and less often one of the other Gram-positive cocci, such as the Group A beta-haemolytic streptococcus (Streptococcus pyogenes) which is found in chronic skin infections, as well as Group B streptococcus (especially in new-born babies) or the alphahaemolytic diplococcus S. pneumoniae.[?]Haemophilus influenzae:In children between 1 and 4 years of age the Gram-negative Haemophilus influenzae used to be a fairly common pathogen for osteomyelitis and septic arthritis, but the introduction of H. influenzae type B vaccination about 20 years ago has been followed by a much reduced incidence of this infection in many countries.In recent years its place has been taken by Kingella kingae, mainly following upper respiratory infection in young children.Other Gram-negative organisms (e.g. Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis and the anaerobic Bacteroides fragilis) occasionally cause acute bone infection.[?]Peptococcus magnus:Anaerobic organisms (particularly Peptococcus magnus) have been found in patients with osteomyelitis, usually as part of a mixed infection.Unusual organisms are more likely to be found in heroin addicts and as opportunistic pathogens in patients with compromised immune defense mechanisms.
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