%0 Journal Article
%T Megacities as Sources for Pathogenic Bacteria in Rivers and Their Fate Downstream
%A Wolf-Rainer Abraham
%J International Journal of Microbiology
%D 2011
%I Hindawi Publishing Corporation
%R 10.1155/2011/798292
%X Poor sanitation, poor treatments of waste water, as well as catastrophic floods introduce pathogenic bacteria into rivers, infecting and killing many people. The goal of clean water for everyone has to be achieved with a still growing human population and their rapid concentration in large cities, often megacities. How long introduced pathogens survive in rivers and what their niches are remain poorly known but essential to control water-borne diseases in megacities. Biofilms are often niches for various pathogens because they possess high resistances against environmental stress. They also facilitate gene transfers of antibiotic resistance genes which become an increasing health problem. Beside biofilms, amoebae are carriers of pathogenic bacteria and niches for their survival. An overview about our current understanding of the fate and niches of pathogens in rivers, the multitude of microbial community interactions, and the impact of severe flooding, a prerequisite to control pathogens in polluted rivers, is given. 1. Introduction A multitude of human activities is usually connected with severe impacts on the environment which also includes human settlements [1]. The growth of human population over the last decades and their concentration in large cities [2] contribute to the deterioration of water quality due to intensifications in the industrial processes, domestic sewage discharge as well as agricultural chemicals and eroded soils [3]. Urban populations have exploded worldwide over the last 50 years [4]. Today about 50% of the global population are living in urban areas [5], placing one-third of their inhabitants into slums [6], and creating huge challenges to their environment and sanitation [7]. In many countries, the rapid development in the last century was not equally followed by equivalent measures to protect the environment. Most cities on this planet are located close to rivers which serve as transport routes and water supplies [8]. Too often these rivers are also used as dump sites for waste water and sewage (Figure 1). The percentage of households with piped or well water nearby or with flush toilets generally decline with city size [9]. Megacities, cities with more than 10 million inhabitants [10], are textbook examples for environmental and health problems caused by such a concentration of humans [11]. Megacities are very dynamic because people from rural areas or small cities migrate into megacities with the hope of a better life. Many of them settle in undeveloped areas with insufficient sanitation standards, worsening the already
%U http://www.hindawi.com/journals/ijmicro/2011/798292/