Antibiotic-resistant strains

Preventive medicine through vaccination continues to be the most cost-effective pubHc health practice, even with the drastic advance in modern medicine. Mass vaccination programs have eradicated smallpox from the earth. The World Health Organization (WHO) has a major campaign underway to eradicate poHo by the year 2000. The development of vaccines has saved millions of Hves and prevented many more from suffering. However, there are stiU many diseases without effective vaccines, such as malaria. With the recent emergence of antibiotic-resistance strains and exotic vimses, an effective vaccine development program becomes a top priority of pubHc health poHcy. 

FAHEY J W, HARISTOY X, DOLAN P M, KENSLER T W, SCHOLTUS I, STEPHENSON K K, TALALAY p and LOZNIEWSKI a (2002) Sulforaphane inhibits extracellular, intracellular and antibiotic-resistant strains of Helicobacter pylori and prevents benzo[a]pyrene-induced stomach tumors , Proc Natl Acad Sci USA, 99 7610-15. 

As carriers of antibiotic resistance (Chapter 3, Part 4) the emergence of antibiotic-resistant strains has had serious repercussions in the application of antibiotic therapy, and has seriously increased the danger of nosicomial infections. 

Pearson and coworkers investigated several antibiotic-resistant strains of E. coli in an elegant and thorough study. Using a combination of MALDI-TOF and electrospray LC-MS they found that varying subtle mutations in ribosomal proteins occur in different strains that are resistant to various anti-... 

Many diseases, including anthrax, are most effectively treated before actual manifestation of the symptoms is observed. Presently a presumptive identification of Bacillus anthracis can be made in about 3 hours however, if a full laboratory response network (LRN) confirmation procedure is utilized, the theoretical time increases substantially to approximately 48 hours. During the recent anthrax cases 72 to 96 hours were common to complete the entire LRN protocol. In the meantime antibiotics were administered as a precaution based on the presumptive results to individuals thought to be exposed to B. anthracis spores or with anthrax symptoms. The mass administering of antibiotics from a cost standpoint, as well as from medical prudence to prevent the rise of antibiotic-resistant strains, is not the optimal answer to the anthrax infection problem. Therefore it is important that early tests be rapid and reliable with a minimum number of false positive and false negative results. 

Mabe S, Champney WS. (2005) A comparison of a new oral streptogramin XRP 2868 with qninnpristindalfopristin against antibiotic-resistant strains of Haemophilus Influenzae, Staphylococcus Aureus, and Streptococcus Pneumoniae. Curr Microbiol 51 363-366. 

An additional disadvantage with many penicillin and cephalosporin antibiotics is that bacteria have developed resistance to the drugs by producing enzymes capable of hydrolysing the P-lactam ring these enzymes are called P-lactamases. This type of resistance still poses serious problems. Indeed, methicillin is no longer used, and antibiotic-resistant strains of the most common infective bacterium Staphylococcus aureus are commonly referred to as MRSA (methicillin-resistant Staphylococcus aureus). The action of P-lactamase enzymes resembles simple base hydrolysis of an amide. 

Concerns with antibiotic use have centered on the potential development of antibiotic-resistant strains of bacteria, and allergic or physiological responses. Customer perceptions about food safety differed by gender, age, and education level. Women were more concerned about quality control and pesticides than men, whereas consumers with at least some college education were more concerned with spoilage and bacteria/germs contamination than those with only a high school education. 

In topical preparations, the base of erythromycin rather than a salt is used to facilitate penetration. Although the mechanism of action of topical erythromycin in inflammatory acne vulgaris is unknown, it is presumed to be due to its inhibitory effects on P acnes. One of the possible complications of topical therapy is the development of antibiotic-resistant strains of organisms, including staphylococci. If this occurs in association with a clinical infection, topical erythromycin should be discontinued and appropriate systemic antibiotic therapy started. Adverse local reactions... 

Meningococcal disease (purulent meningitis) commonly occurs in children, but is also observed in adults. Without antibiotic treatment, the mortality rate is high (85%), and, even with this treatment, cured patients can suffer serious and permanent neurological deficiencies.165 These facts, together with the emergence of antibiotic-resistant strains,8 prompted the rapid development of a commercial vaccine. This vaccine was developed almost simultaneously with the pneumococcal vaccine. 

Clearly, efflux is a major mechanism of multidrug resistance and several authors [41, 42, 71] are now reconsidering reduced drug accumulation in terms of efflux rather than as cellular impermability. It is, however, pertinent to query whether efflux of biocides is of relevance in relation to the concentrations employed in practice and whether biocides are responsible for selecting antibiotic-resistant strains as has been suggested. Clearly, much future experimentation is needed to establish a direct link between antibiotic and biocide resistances. 

Infections can usually be treated with penicillinase-resistant B-lactams. Infections acquired in the hospital are often antibiotic resistant strains and can only be treated with vanomycin. Vaccines are not currently available. 

Most people are familiar with CFCs (chlorofluorocarbons) and how they eventually became doomed as an input into modern industrial products. Ironically, these compounds were initially introduced as environmentally perfect alternatives due to their nontoxic and nonbioaccumulative nature. This is one of many examples of decisions - in this case about safe materials - that have been made on large scale, only to be followed by a late awakening and significant costs to society and individual organizations. Some of the more recent examples now looming on the horizon may be even worse due to their direct impacts on humans - antibiotic-resistant strains of microbes from antibiotics in biota, hampered kidney function from cadmium in foods, and endocrine disruption from plastic additives, to mention just a few. 

The pH indicator phenol red (phenol sulfonphtha-lein) is often added to commercially available media. It is pale yellow at pH 6.5, orange at pH 7.0, and red at pH 7.4. It becomes purplish above pH 7.4. Growth media are also often supplemented with antibiotics to promote the growth and propagation of antibiotic resistant strains and also to prevent contamination by micro-organisms. But the presence of antibiotics in the medium does not obviate the use of good aseptic techniques. Nowadays, however, most commercially available media are presterilized as are the polystyrene culture dishes. 

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