Scientists have found some bone infections are caused by a newly discovered species of bacteria that are related to the tuberculosis pathogen.

The researchers said their finding might help to improve the diagnosis and treatment of similar infections. They noted some rare genetic diseases can make patients susceptible to infections with Mycobacterium species, the bacteria which cause tuberculosis and leprosy. Those patients often suffer from recurring mycobacterial infections throughout their lives.

Scientist isolated an unknown species of bacteria from a 7-year-old child who has a genetic immune defect “The infection had caused bone lesions and here the newly described bacterium was found.

"Initial tests suggested that it was a Mycobacterium. By sequencing some of the bacterium's genes it showed that scientists have discovered an un-described species, which was called Mycobacterium arosiense."

The name comes from Arosia, the Latin name of the city of Aarhus in Denmark , which is where the bacterium was found.

Source: Int J Syst Evol Microbiol 2008, 58 (10): 2398-2402

Atopic dermatitis (AD), a common form of eczema affecting 10 to 20% of children and 1 to 3% adults, usually precedes the development of asthma and other allergic disorders. Individuals affected with the chronic skin disorder are also at an enhanced risk of developing other cutaneous infections due to Staphylococcus aureus , Herpes simplex , vaccinia or small pox virus, and Molluscum . A recent study published suggests that oral vitamin D supplements induce the production of the broad spectrum antimicrobial peptide, cathelicidin in the skin and thereby, prevent skin infections due to atopic dermatitis.

Source: J Allergy Clin Immunol 2008; 122(4): 829 – 31

A group of scientists found that a number of proteins secreted by neutrophils (PMNs) enhance uptake of bacteria by macrophages, which are capable of destroying the microbes.

In the study, proteins secreted by human PMNs, specifically HBP and HNP1-3 were found to enhance the in vitro ability of human and mouse macrophages to take up bacteria coated in the immune molecule IgG.

These two proteins activated the macrophages to secrete soluble factors, TNF-a and IFN-y that in turn induced the macrophages to express proteins to which IgG can bind (CD32 and CD64).

Source: J clin Invest, 2008; 118(10): 3491 – 3502

Glycopeptides have been the antimicrobials most commonly used for infections by Gram-positive organisms and methicillin resistant S. aureus (MRSA). In recent years, however glycopeptides resistance and tolerance have become a serious problem. Thus, enterococci highly resistant to vancomycin, vancomycin-intermediate/ resistant S. aureus (VISA), and vancomycin tolerance in S. aureus are found, and increased therapeutic failure and mortality are clinically reported with vancomycin MIC for S. aureus >/= 1.5-2 mug/mL. When faced with these organisms, we therefore need potent bactericidal antimicrobials that may be empirically administered, effective against susceptible and resistant pathogens, easily dosed, with few adverse effects and no significant interaction with other drugs and that can be administered in an outpatient setting. In bacteremia by methicillin-susceptible S. aureus , use of vancomycin is associated to a greater failure and mortality rate as compared to semisynthetic penicillins. New treatment options for MRSA infections include daptomycin, linezolid, tygecycline, and quinupristin/dalfopristin. New anti-MRSA drugs are also under development, including glycopeptides (dalbavancin, telavancin, and oritavancin), ceftobiprole, and iclaprim.

Source: Nefrologia. 2008; 28(6):119-24.

The efficacy of oral Cefditoren pivoxil and conventional oral amoxicillin for pharyngotonsillitis caused by group A streptococcus in children was compared. Either oral Cefditoren-pivoxil (3 mg/kg t.i.d. for 5 days) or amoxicillin (10 mg/kg t.i.d. for 10 days) was administered to patients with group A streptococcal pharyngotonsillitis attending the pediatric outpatient clinic. Diagnosis was based on isolation of bacteria from a pharyngeal swab. Culture was always done to confirm eradication, and urinalysis and follow-up were performed at least once weekly for 4 weeks. Among 258 patients, 103 (aged 5.5 +/- 2.3 years) received Cefditoren pivoxil and 155 (aged 5.2 +/- 2.0 years) received amoxicillin. There were no significant between-group differences in age, sex, or symptoms. Eradication was confirmed in 99% (102/103) of the Cefditoren pivoxil group and 100% of the amoxicillin group. Recurrence within 4 weeks occurred in 8 and 15 patients in the Cefditoren pivoxil and amoxicillin groups, respectively showing no significant difference in the recurrence rate, and all isolates had the same serotypes as before. There were no clinically significant adverse reactions or complications. The 50%/90% minimum inhibitory concentrations (microg/ml) of Cefditoren pivoxil and amoxicillin for the 258 isolates were < or =0.03/< or =0.03 and < or =0.03/0.06, respectively, so all isolates were susceptible to both agents. Because the efficacy for pediatric group A streptococcus pharyngotonsillitis was similar between oral Cefditoren pivoxil for 5 days and amoxicillin for 10 days, the shorter treatment period may make the former regimen preferable.

Source: J Infect Chemother. 2008, 14(3):213-8.