Resistance is a natural biological outcome of antibiotic use

The triumph of antibiotics over disease-causing bacteria is one of modern medicine's greatest success stories. Since these drugs first became widely used in the World War II era, they have saved countless lives and blunted serious complications of many feared diseases and infections. Over time, some bacteria have developed ways to outwit the effects of antibiotics. The current worldwide increase in resistant bacteria and, simultaneously, the downward trend in the development of new antibiotics have serious implications. Resistant bacteria dramatically reduce the possibilities of treating infectious diseases effectively and multiply the risks of complications. Most vulnerable are those with weakened immune defenses, such as cancer patients, malnourished children and people who are HIV-positive, for whom adequate therapy to prevent and treat severe infections is often necessary for their survival. In addition, antibiotic resistance jeopardizes advanced medical procedures such as organ transplantations and implants of prostheses, where antibiotics are crucial for patient safety and to avoid complications.

Resistance is a natural biological outcome of antibiotic use. The more we use these drugs, the more we increase the speed of emergence and selection of resistant bacteria.  The relationship between antibiotic use and resistance is complex. Under use, through lack of access to antibiotics, inadequate dosing and poor adherence to therapy may play as important role in driving resistance as overuse.

The use of broad-spectrum antibiotic agents as a substitute for precise diagnostics or to enhance the likelihood of therapeutic success increases the rate of selection of resistant bacteria. In addition, counterfeit and substandard drugs contribute to sub-optimal concentrations of antibiotics, failing to control bacterial populations that are considered a risk factor for developing resistance. It is estimated that over 50 percent of antibiotics worldwide is purchased privately, from pharmacies or in the informal sector from street vendors, without prescriptions. Half of the purchases are for one-day treatments or less, an example reflecting the magnitude of the problem. Consequently, there is a clear justification for initial broad spectrum therapy in severe infections. This moves us into a vicious circle where increasing levels of resistance necessitate the use of broader, more potent antibiotics to secure patient survival but where using these reserve antibiotics escalates the problem as resistance develops and creates a situation where effective antibiotics are lacking. Once resistant strains are selected, their spread is promoted by factors such as overcrowding and poor hygiene especially in hospitalized patients.

Enterococci are the most important multidrug resistant microorganism that are associated with both community- and hospital-acquired infections. Enterococci are considered as  normal inhabitants of the intestinal tract, oral cavity and the genitourinary tract of the humans and animals. They are released into the environment by animal waste and fertilizers of animal origin. In contrast to coliforms and other intestinal indicator bacteria, the enterococci are rather tough and can survive for long periods of time in soil and water, and thus re-enter the food chain.  Even though they do not cause severe systemic inflammatory responses, such as septic shock, enterococci present a therapeutic challenge because of their resistance to a vast array of antimicrobial drugs, including cell-wall active agents, all commercially available aminoglycosides, penicillin, ampicillin and vancomycin. This emphasizes the need for their identification from the clinical specimens and also differentiates them from other group D streptococci which are generally more sensitive to the antimicrobial agents.

Glycopeptide antibiotic (vancomycin) is considered as reserved antibiotic for the treatment of serious diseases caused by multidrug resistance Gram-positive organisms. If enterococci develop resistance to this antibiotic as a result of misuse we may loose the last effective antibiotic.

Vancomycin-resistant enterococci (VRE) are resistant to all presently available antibiotics have started to appear, these pathogens are now the second-leading cause of nosocomial infections in the United States. VRE infections tend to occur in more debilitated patients and are associated with mortality rates of 60% to 70%. The most common types of infections attributed to VRE include urinary tract infections, endocarditis, meningitis, bacteremia, intra-abdominal infections.

There are a lot of theories about the distribution of resistance, possibly due to the use of hospital sewage in agriculture or drainage of this sewage to the sea which affect on the food chain. This is regarded as very alarming, since colonized patients in hospitals as well as animals and environment can serve as significant reservoirs for human acquisition of VRE. There is no information or data available about the epidemiology of this critical problem in Gaza city. Thus we need to examine the occurrence and prevalence of VRE in fecal samples from hospitalized patients and non-hospitalized individual in Gaza city.