Promising antibiotic alternative to fight bacteria that causes strep throat

Feb 22, 2012

Researchers have discovered a promising alternative to common antibiotics used to fight the bacteria that causes strep throat. In an article published in the Proceedings of the National Academy of Sciences, the scientists discussed how their discovery could fight the infection with a reduced risk of antibiotic resistance.

By screening tens of thousands of small molecules, the team from the University of Missouri and University of Michigan identified a class of chemical compounds that significantly reduced the severity of group AStreptococcus (GAS) bacteria infection in mice. Their work suggests that the compounds might have therapeutic value in the treatment of strep and similar infections that affect an estimated 700 million people around the world each year. The newly identified compounds could work with conventional antibiotics, such as commonly prescribed penicillin, and result in more effective treatment.

"We know that 70 percent of bacteria causing infections in the hospital are resistant to at least one of the drugs commonly used for treatment," said Hongmin Sun, PhD, the article's first author and an assistant professor of internal medicine at the University of Missouri. "Rather than killing off the bacteria, this new compound changes the behavior of the bacteria and makes it less harmful."

Current antibiotics interfere with critical biological processes in the pathogen to kill it or stop its growth. But at the same time, stronger strains of harmful bacteria can sometimes resist the treatment and flourish.

"The widespread occurrence of antibiotic resistance among human pathogens is a major public health problem," said David Ginsburg, MD, a professor of internal medicine, human genetics, and pediatrics at the University of Michigan and a Howard Hughes Medical Institute investigator.

Source: University of Missouri School of Medicine

Zinc plus antibiotics saves lives of children with pneumonia, study finds

Zinc plus antibiotics saves lives of children with pneumona, study finds

Publish date: Feb 24, 2012
By: Formulary staff

Zinc used in addition to antibiotics significantly reduced mortality in children ages 6 months to 59 months with severe pneumonia when compared with antibiotics alone, according to the findings of a recent study done in Uganda.

The study, published online February 8 in BMC Medicine, also indicated that the adjunct therapy had a greater effect among HIV-infected children than those who were not infected with HIV.

The double-blind, randomized, placebo-controlled study was led by Maheswari G. Srinivasan, from the Department of Pediatrics and Child Health at the School of Medicine, in Uganda. Researchers enrolled 352 children, aged 6 months to 59 months, who were admitted to the Mulago Hospital pediatric emergency ward with severe pneumonia between September 2006 and March 2007.

"There are 2 key findings in this study: overall, zinc supplementation in these children significantly decreased case fatality, but did not reduce the time to normalization of the parameters for disease severity," the authors stated, noting that these findings come from the secondary objective rather than the primary objectives, which were to assess the effect of zinc as an adjunct therapy on time to normalization of respiratory rate, temperature, and oxygen saturation.

The investigators randomly assigned the children to receive standard antibiotic therapy plus zinc (10 mg for children aged under 12 months; 20 mg for children 12 months and older) or standard antibiotic therapy plus placebo daily. The children were assessed every 6 hours for the first 48 hours and then every 12 hours for 7 days of treatment.

The investigators found no evidence that zinc decreased length of time to recovery. They did, however, note the number of deaths was lower among the children who were treated with zinc (4.0% vs 11.9%; RR=0.33; 95% CI, 0.15-0.76).

In addition, the researchers noted that the effect of zinc supplementation appeared stronger among children infected with HIV. There were more deaths among HIV-positive children assigned to placebo compared with those who received zinc (25.9% vs 0%; RR=0.1; 95% CI, 0.0-1.0).

Among those children who were not infected with HIV and who received placebo, the death rate was 5.5% versus 3.9% among HIV-uninfected children who received zinc (RR=0.7; 95% CI, 0.2-2.2).

“Acute respiratory tract infections are the most common cause of morbidity and deaths in children less than 5 years,” the authors wrote in their background. “Given these results,” the authors stated, “zinc could be considered for use as adjunct therapy for severe pneumonia, especially among Highly Active Antiretroviral Therapy-naïve, HIV-infected children in our environment.”

Modern Medicine

Potential Antibiotics Alternative to Treat Infection Without Resistance

Potential Antibiotics Alternative to Treat Infection Without Resistance

Curious Cat Science and Engineering Blog | Thursday, February 23, 2012

Researchers at the University of Michigan have found a potential alternative to conventional antibiotics that could fight infection with a reduced risk of antibiotic resistance. Sadly Michigan is another school that is allowing work of those paid for by the citizens of Michigan to be lock away, only due to the wishes of an outdated journal business model instead of supporting open science. The Big Ten seems much more interested in athletic riches than in promoting science. The Big Ten should be ashamed of such anti knowledge behavior and require open science for their schools if they indeed value knowledge.

By using high-throughput screening of a library of small molecules, the team identified a class of compounds that significantly reduced the spread and severity of group A Streptococcus (GAS) bacteria in mice. Their work suggests that the compounds might have therapeutic value in the treatment of strep and similar infections in humans.

“The widespread occurrence of antibiotic resistance among human pathogens is a major public health problem,” said David Ginsburg, a faculty member at LSI, a professor of internal medicine, human genetics, and pediatrics at the U-M Medical School and a Howard Hughes Medical Institute investigator.

Ginsburg led a team that included Scott Larsen, research professor of medicinal chemistry and co-director of the Vahlteich Medicinal Chemistry Core at U-M’s College of Pharmacy, and Hongmin Sun, assistant professor of medicine at the University of Missouri School of Medicine.

Work on this project is continuing at U-M and the University of Missouri, including the preparation of new compounds with improved potency and the filing of patents, Larsen said. Large research schools are also very interested in patents. That is ok, though seems to cloud the pursuit of knowledge too often when too large a focus is on dollars at many schools. But, it seems to put the schools primary focus on dollars; education seems to start to be a minor activity at some of these large schools.

Current antibiotics interfere with critical biological processes in the pathogen to kill it or stop its growth. But at the same time, stronger strains of the harmful bacteria can sometimes resist the treatment and flourish.

An alternate approach is to suppress the virulence of the infection but still allow the bacteria to grow, which means there is no strong selection for strains that are resistant to antibiotics. In a similar experiment at Harvard University, an anti-virulence strategy was successful in protecting mice from cholera.

About 700 million people have symptomatic group A Streptococcus infections around the world each year, and the infection can be fatal. Most doctors prescribe penicillin. The newly identified compounds could work with conventional antibiotics and result in more effective treatment.

ECNMag.com

Antibiotic prescription and prevalence rate in the outpatient paediatric population: analysis of surveys published during 2000-2005.

Antibiotic prescription and prevalence rate in the outpatient paediatric population: analysis of surveys published during 2000-2005.
Eur J Clin Pharmacol. 2007 Sep 21
Rossignoli A, Clavenna A, Bonati M.
Laboratory for Mother and Child Health, Mario Negri Institute for Pharmacological Research, via G. La Masa 19, 20156, Milan, Italy, clavenna@marionegri.it.

OBJECTIVE: To evaluate antibiotic paediatric consumption data in the community setting using data from studies published between 2000 and 2005 and to compare inter- and intra-country antibiotic prescribing patterns.

METHODS: A literature search was performed in EMBASE and MEDLINE to identify pharmacoepidemiological studies published between 2000 and 2005.

RESULTS: Large differences between studies were found, with significant heterogeneity in epidemiological indicators. Only 20 studies reporting comparable drug prescription data were considered in the analysis, all of which were from the USA, Canada, North-Central Europe and Italy. Pre-school children were reported as comprising the most exposed age group to antibiotic therapy (prevalence 72%; prescription rate 2.2 prescriptions/person per year). In the overall child and adolescent population (less or equal to 19 years), prevalence varied from 14 to 57% (mean 34%), and the prescription rate from 0.2 to 1.3 prescriptions/person per year. Relevant inter-country qualitative and quantitative differences in antibiotic prescribing were apparent, although these were observed in only a few countries: prevalence was higher in Italy and Canada (prevalence range 42-57%) and lower in the Netherlands and the United Kingdom (prevalence range 14-21%). Penicillins were the most prescribed antibiotics in all cases (40-70% of antibiotic prescriptions), followed by macrolides (16-45%), while cephalosporins accounted for a large proportion of the prescriptions in Italy (30-40%) and Canada, but were practically absent in North European prescriptions.

CONCLUSION: Comparative drug utilisation studies on antibiotic use in children are needed, as are improvements in regulatory and educational programmes aimed at limiting the number prescriptions given for antibiotics. Both approaches would address public health problems, such as bacterial resistance and safety and elevated costs, related to the use and misuse of these drugs.

PMID: 17891535 [PubMed - as supplied by publisher]