Re: Intracellular Staph and abx resistance: implications for osteomyelitis

[Guest guest]

Wow, well this certainly confirms my own observations with my

osteomyelitis and the way I react to abx. Why low dose, sporadic abx

dosing is a very bad idea if you've got bugs in the bone, which I

believe many of us have.

penny

>

> J Orthop Res. 2006 Jan;24(1):87-93. Related Articles, Links

>

>

> Intracellular Staphylococcus aureus and antibiotic resistance:

> implications for treatment of staphylococcal osteomyelitis.

>

> Ellington JK, M, Hudson MC, Vishin S, Webb LX, Sherertz R.

>

> Department of Orthopaedic Surgery, Carolinas Medical Center, 1000

> Blythe Boulevard, Charlotte, North Carolina 28223, USA.

>

> Staphylococcus aureus is responsible for 80% of human

osteomyelitis.

> It can invade and persist within osteoblasts. Antibiotic resistant

> strains of S. aureus make successful treatment of osteomyelitis

> difficult. Null Hypothesis: antibiotic sensitivities of S. aureus

do

> not change after exposure to the osteoblast intracellular

> environment. Human and mouse osteoblast cultures were infected and

> S. aureus cells were allowed to invade. Following times 0, 12, 24,

> and 48 h ( +/- the addition of erythromycin, clindamycin, and

> rifampin at times 0 or 12 h), the osteoblasts were lysed and

> intracellular bacteria enumerated. Transmission electron

microscopy

> was performed on extracellular and intracellular S. aureus cells.

In

> mouse osteoblasts, administration of bacteriostatic antibiotics at

> time 0 prevented the increase in intracellular S. aureus. If the

> antibiotics were delayed 12 h, this did not occur. When rifampin

> (bactericidal) was introduced at time 0 to human and mouse

> osteoblasts, there was a significant decrease in number of

> intracellular S. aureus within osteoblasts compared to control. If

> rifampin was delayed 12 h, this did not occur. Significant time-

> dependent S. aureus structural changes were observed after

exposure

> to the osteoblast intracellular environment. These studies

> demonstrate that once S. aureus is established intracellularly for

> 12 h, the bacteria are less sensitive to antibiotics capable of

> eukaryotic cell penetration (statistically significant). These

> antibiotic sensitivity changes could be due in part to the

observed

> structural changes. This leads to the rejection of our null

> hypotheses that the antibiotic sensitivities of S. aureus are

> unaltered by their location.

>

> PMID: 16419973 [PubMed - indexed for MEDLINE]

>