This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteriology, Subject name: Microbiology
The most common agent causing osteomyelitis in sickle cell disease patients? 
Select and explain. 
A. Salmonella enteritidis, B. E.coli, C. Klebsiella, D. Enterococcus
A: Salmonella enteritidis
Answer: A: Salmonella enteritidis 
Explanation: Salmonella Subspecies other than typhi (S. enteritidis, S. typhimurium)Facultative gram-negative rods, non-lactose-fermenting on EMB, MacConkey medium* Produces H2S, motile (unlike Shigella)* Speciated with biochemical reactions and serotyped with O, H, and Vi antigensDiseases:* Enterocolitis/gastroenteritis (second most common bacterial cause after Campylobacter): 6- 48-hour incubation; nausea; vomiting; only occasionally bloody, loose stools; fever; abdominal pain; myalgia; headache* Septicemia (S. enterica subsp. choleraesuis, S. enterica subsp. paratyphi, and S. enterica subsp. dublin): usually in very young or elderly when it occurs; endocarditis or ahritis complicates 10% of cases* Osteomyelitis: sickle cell disease predisposes to osteomyelitis; Salmonella is most common causal agent of osteomyelitis in sickle cell disease (not trait) patients (>80%).Ref: Ananthanarayan; 7th edition; Page no: 303