Indicators of microbial quality *
Jamie Bartram, Rachel Baum, Peter A. Coclanis, David M. Gute, David Kay, Stéphanie McFadyen, Katherine Pond, William Robertson, Michael J. Rouse in Routledge Handbook of Water and Health, 2015
In 1677, Antonie van Leeuwenhoek reported the first microbial count in a water sample: 2,730,000 “animalcules” in a volume he estimated to be the size of a pea (Egerton 2006). From that time we have known that water is teeming with microbial life. Some microbes present in water may be readily detected using basic culture methods. Others require advanced and relatively recently developed molecular techniques. Our knowledge about the microbial communities that inhabit water is still basic and mostly utilitarian: we pay especially careful attention to those microbes we know can make us sick. When we refer to “microbial quality” of water, we mean its safety for drinking, recreation, irrigation, and other uses that may result in human contact. Therefore we mean the presence or potential presence of pathogenic microbes.
Pathogenicity and Virulence
Julius P. Kreier in Infection, Resistance, and Immunity, 2022
Any microorganism that is able to infect a host and produce disease is a pathogen. IVllcroorganisms vary in their ability to produce disease; some organisms such as Vibrio cholerae, the agent of cholera, or Yersinia pestis, the cause of plague, are able to produce disease in normal healthy hosts. These bacteria are thus overt pathogens and must be distinguished from those organisms which function as opportunists and produce disease only when a break in the host′s normal defense mechanisms enables them to become established. Included in this latter group of opportunists are members of the normal flora such as Escherichia coli, Staphylococcus aureus, and certain fungi such Candida albicans, as well as some free-living bacteria such as Pseudomonas aeruginosa and Legionella pneumophila.
Potential of Herbal Extracts and Bioactive Compounds for Human Healthcare
Megh R. Goyal, Hafiz Ansar Rasul Suleria, Ramasamy Harikrishnan in The Role of Phytoconstitutents in Health Care, 2020
According to the World Health Organization (WHO), about one-third of all deaths are due to infectious diseases, and nearly 50,000 people die each day globally. Antibiotics continue to be a major therapeutic discovery in the effective control of pathogens. Numerous broad spectrum and pathogen-specific drugs to control microbes are available today. Though the treatment with antibiotics offers significant advantages, yet their use is still arbitrary today, thus resulting in an alarming increase in antibiotics resistance of virulent strains. The indiscriminate or improper usage of antimicrobial drugs has increased drug resistance among microorganisms [971]. The high degree of multidrug resistance is due to the presence of antibiotic efflux systems, which trigger resistance to pathogens [5]. Indeed drug resistance among pathogens poses a serious threat throughout the world [5, 210, 751, 878]. Therefore, the exploration of a new generation of drugs is a continuous pursuit, because the target microorganisms continue to develop new virulent strains that have become further resistant to currently existing antimicrobial drugs [254, 1031]. Also, new families of antimicrobial drugs frequently have short life expectancy [184]. Hence, there is a dire need to explore novel groups of antibacterial agents.
Quorum sensing: a new prospect for the management of antimicrobial-resistant infectious diseases
Published in Expert Review of Anti-infective Therapy, 2021
Mainul Haque, Salequl Islam, Md Arif Sheikh, Sameer Dhingra, Peace Uwambaye, Francesco Maria Labricciosa, Katia Iskandar, Jaykaran Charan, Alaeddin Bashir Abukabda, Dilshad Jahan
Pathogenic microbes produce diverse virulence factors to survive in the host system and cause physical damage. Microbial toxins are essential components of a microbes virulence factors [174]. Immunized animal serum was utilized widely as the principal method of treatment for various infectious diseases including diphtheria, tetanus, scarlet fever, pneumococcal pneumonia, and meningitis caused by Neisseria meningitis and Haemophilus influenza in the pre-antibiotic era [175]. The use of antibodies for the management of microbial diseases was first reported in 1890 [176]. Serum from immunized horses provided the first effective treatment against Clostridium tetani and Corynebacterium diphtheriae infections [177]. Moreover, the QS signaling system controls microbial toxin production mechanisms [112,178]. Bacterial toxins, encoded by microbial chromosomal genes, plasmids, or phages, are often responsible for lethal pathological manifestations among infected individuals [179]. Microbial toxins are ‘non-replicating, non-infectious, non-contagious, and non-curable’ by antimicrobial medicine [180].
Bacterial effluxome as a barrier against antimicrobial agents: structural biology aspects and drug targeting
Published in Tissue Barriers, 2022
Pownraj Brindangnanam, Ajit Ramesh Sawant, K. Prashanth, Mohane Selvaraj Coumar
The microbial universe was discovered and introduced to the world by the legends Robert Hooke and Antoni van Leeuwenhoek through serendipity in the 16th century.1Particularly, the discovery of bacteria by Leeuwenhoek was one of the greatest contributions to science and biology, which changed our vision of the biome we live in. Later discoveries identified that some of the microbes are beneficial to the host and some are pathogenic causing diseases in the host. Pathogenic microbes had played a crucial role in the survival history of mankind.2 For instance, Plague or black death (165–180 AD, killed one-third of the world population in the 13th century), malaria (18th century), Spanish influenza (pandemic 1918–1920), tuberculosis (TB in 19th century), smallpox (1972), HIV pandemic (the early 1980s), SARS (21st century), and SARS-COV-2 (late 2019s) outbreaks have resulted in millions of death and affected the livelihood of many worldwide.3–6
The pharmacological treatment of bronchiectasis
Published in Expert Review of Clinical Pharmacology, 2018
Andrea S Melani, Nicola Lanzarone, Paola Rottoli
Microbiologic sputum examinations are very important. The subject’s sputum should be assessed for routine bacteriology, mycobacteria, and fungi. The finding of Aspergillus spp. from sputum may underscore the Allergic BronchoPulmonary Aspergillosis (ABPA), a variety of bronchiectasis associated with asthma and hypersensitivity reaction [8–10]. The most significant pathogen bacteria are Moraxella catharralis, Haemophilus influenzae, enteric Gram negative germs, Burkholderia cepacia, Staphylococcus aureus, Streptococcus pneumonia, and Pseudomonas aeruginosa (PsA). Haemophilus influenzae is a main driver of inflammation [36], but the persistence of PsA isolates in the sputum is mostly recognized as the key marker of bronchiectasis severity [37]. Research utilizing gene sequencing is a sensitive alternative to culture-based methods of assessing lung microbiome [37–39]. Similar to sputum culture, these methods confirm that the predominance of PsA is associated with frequent exacerbations, worsening of FEV1, and severe disease [37], but also show germs not typically detected by routine cultures such as Veilonella and Prevotella [38]. In addition, they reveal limited variation in composition of lung microbiome over time despite changes in clinical status and the use of antibiotics. There is mounting evidence that the decreasing diversity of lung bacterial populations is associated with severe disease [39].
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