Pocket Guide to Bacterial Infections

K Balamurugan, Prithika Udayakumar

• Publisher: CRC Press
• Year: 2019
• ISBN:
  9781351679800
• Edition: 1
• Topic: Medicine
• Subtopic: Infectious Diseases

Pocket Guide to Bacterial Infections provides information pertinent to the behaviour of bacterial cells during their interactions with different cell types of multiple host systems. This book will present the role of various bacterial pathogens affecting the host system. The book is to be organized flexibly so that chapters and topics are arranged with continuity from the former chapters. Each chapter has been made as self-contained as possible to promote this flexibility. This book will discuss each of the virulence properties of the bacteria with reference to their interacting hosts in a larger perspective.

Kwey selling features:

• Summarizes the role various bacterial pahtogens affect the host system
• Reviews recent advances for combating different types of bacterial infections that infect different body parts
• Designed as an effective teaching and research tool providing up to date information on bacterial infections
• Defines important terms
• Written in a readable and direct writing style

1

Bacteria Causing Gastrointestinal Infections

Overview of Types of Bacteria Causing Gastrointestinal Infections, Mode of Infection, Challenges in Diagnostic Methods, and Treatment

B. Vinoth, M. Krishna Raja, and B. Agieshkumar

Contents

1.1 Bacterial infections of the gut

1.1.1 Introduction

1.2 Escherichia coli

1.2.1 Enteropathogenic E. coli (EPEC)

1.2.1.1 Pathogenesis

1.2.1.2 Clinical features

1.2.1.3 Diagnosis

1.2.1.4 Treatment

1.2.2 Enterotoxigenic E. coli (ETEC)

1.2.2.1 Pathogenesis

1.2.2.2 Clinical features

1.2.2.3 Diagnosis

1.2.2.4 Treatment

1.2.3 Entero Hemorrhagic E. coli (EHEC) (STEC/VTEC)

1.2.3.1 Pathogenesis

1.2.3.2 Clinical features

1.2.3.3 Diagnosis

1.2.3.4 Treatment

1.2.4 Enteroinvasive E. coli (EIEC)

1.2.5 Enteroaggregative E. coli (EAEC)

1.2.6 Diffusely Adherent E. coli (DAEC)

1.3 Shigella

1.3.1 Pathogenesis

1.3.2 Clinical features

1.3.3 Diagnosis

1.3.4 Treatment

1.3.5 Prevention

1.4 Salmonella

1.4.1 Nontyphoidal salmonellosis

1.4.2 Salmonella typhi

1.4.2.1 Clinical features

1.4.2.2 Diagnosis

1.4.2.3 Treatment

1.5 Campylobacter

1.5.1 Pathogenesis

1.5.2 Clinical features

1.5.3 Diagnosis

1.5.4 Treatment

1.5.5 Prevention

1.6 Yersinia

1.6.1 Pathogenesis

1.6.2 Clinical features

1.6.3 Diagnosis

1.6.4 Treatment

1.7 Clostridium difficile

1.7.1 Incidence

1.7.2 Clinical and microbiological properties

1.7.3 Clinical features

1.7.4 Pathogenesis

1.7.5 Diagnosis

1.7.6 Non-laboratory-based tests

1.7.7 Treatment

1.8 Clostridium perfringens

1.8.1 General microbiology

1.8.2 Incidence

1.8.3 Symptoms

1.8.4 Pathogenesis

1.8.5 Diagnosis

1.8.6 Treatment

1.9 Vibrio

1.10 Aeromonas

1.11 Plesiomonas

1.12 Bacteriodes fragilis

1.13 Helicobacter pylori

1.13.1 Pathogenesis

1.13.2 Symptoms

1.13.3 Diagnosis

1.13.4 Treatment

1.14 Foodborne illness and food poisoning

1.14.1 Introduction

1.14.2 Staphylococcus aureus

1.14.3 Bacillus cereus

1.14.3.1 Clinical symptoms

1.14.3.2 Laboratory test

1.14.4.3 Treatment

1.14.4 Listeria monocytogenes

1.14.5 Vibrio vulnificus

1.14.6 Cronobacter sakazaki

1.14.7 Mycobacterium tuberculosis

1.15 Future perspective

References

Gastrointestinal (GI) infections are bacterial, parasitic, or viral infections that cause gastroenteritis, an inflammation of the GI tract. A wide range of GI diseases are caused by bacteria, when bacteria or its associated toxins are ingested through contaminated food or water. Though most bacterial GI illness is short lived and self-limiting, it can be fatal, if not treated properly.

This remains a common problem in both primary care and emergency centers in the developing world. Some of the major bacteria that causes GI illness include Escherichia coli, Salmonella spp., Shigella, Campylobacter spp., Clostridium spp., Yersinia, and Bacillus cereus. This chapter discusses different types of causative bacteria, mode of infection, and mechanism that contributes to pathophysiology of the disease. This review also adds a note on various methods and challenges in diagnosis and treatment of bacteria causing GI infections.

1.1 Bacterial infections of the gut

1.1.1 Introduction

GI infection caused by bacteria is common throughout the global population, causing significant morbidity and mortality (Ternhag et al. 2008). The disease burden is to such an extent that it stands second in mortality of children younger than 5 years of age. Epidemic outbreak of some bacteria often resulted in high mortality and liability to the community. For instance, around 0.7 million children younger than age of 5 lost their lives among the 1.7 billion diarrheal episodes in the year 2010–2011 (Walker et al. 2013). A changing burden of GI infections around the world is being reported with several newly recognized organisms causing GI disease in the last three decades (Eslick 2010).

The gastrointestinal tract (GIT) is the home for several commensal bacteria living in harmony with the host. This is however being disrupted by some organisms like Escherichia coli, Clostridium perfringens, and Clostridium difficile, which can cause infection of the GIT. Apart from these, many pathogenic bacteria can enter the GIT through contaminated food (i.e., food poisoning) or through some other route (i.e., tuberculosis) and cause infection. Foodborne diarrheal illness is one of the leading causes of acute diarrheal illness worldwide and commonly seen even in developed countries. Bacteria causing GIT infections hence can be grouped into two types (i) primary enteropathogens, which includes bacteria that are gram-negative with specific affinity to enterocytes and has specific pathogenic factors against intestinal epithelial cells. (ii) The second group are those which cause gastroenteritis as a part of foodborne illness with many of them having affinity and pathogenic targets toward other organ systems in addition to GIT. The GI infections manifest either primarily with symptoms like nausea, vomiting, abdominal pain, diarrhea, and fever or along with systemic symptoms like arthritis, hepatitis, renal failure, and so on, depending upon the severity (Shaheen et al. 2006; Goh 2007).

Based on the pathogenesis, these organisms produce either watery or bloody diarrhea. Most of the infections are mild and are associated with only watery diarrhea; however, few organisms are known to produce bloody diarrhea like, Shigella, enterohemorrhagic E. coli (EHEC), Salmonella, Campylobacter, and Yersinia. Gut infections are mostly foodborne, and the leading cause is Salmonella, followed by Campylobacter, Shigella, and enterotoxigenic E. coli (ETEC) according to an US data in 2014. The type of food associated with these infections is also different for different organisms. The frequencies of this infection differ between countries and depend on the health status of the community, weather conditions, food habits, and so on. Despite these differences, it is practically difficult to diagnose a specific organism as a cause primarily based on clinical grounds. The usual way of diagnosing a specific infection is only by isolating the organism in most of these cases. But isolation of certain organisms in this group is difficult and involves either a transport medium or a highly selective medium or application of special techniques. In addition certain organisms like E. coli requires molecular methods for knowing the subtypes which are not routinely available and are restricted to reference laboratories. Hence, evaluating patients with diarrheal illness is cumbersome.

Most of these illness are self-limiting lasting only for few days and do not require antibiotics. Only severe and complicated cases require antibiotics, and in fact in some cases, antibiotics might even be harmful as with EHEC. Bacteria developing resistance toward antibiotics makes it mandatory to know the sensitivity pattern before selecting an antibiotic. This makes the isolation of organism even more important. As mentioned before, there has also been a changing trend of bacteria with falling incidence of well-known older infections (i.e., EHEC O157, Vibrio cholerae) and increasing incidence of other organisms (i.e., Campylobacter, Yersinia) with few maintaining a constant trend (i.e., Salmonella), and finally with lots of emerging organisms (i.e., Arcobacteria, Edwardsiella tarda, Plesiomonas shigelloides, Aeromonas hydrophila, Listeria monocytogenes, and Laribacter hongkongensis). This chapter discusses the general biology and transmission means of more common and emerging bacterial pathogens causing GI infection and describes various diagnostic and treatment methods. The order of the pathogens represents their contribution toward disease severity.

1.2 Escherichia coli

E. coli is the foremost gram-negative facultative anaerobic bacilli residing in the intestines of humans and other mammals. Most of the strains remain harmless, but few cause mild to severe diarrheal illness. Six major types of E. coli based on their pathogenesis are ETEC, enteropathogenic E. coli (EPEC), enteroinvasive E. coli (EIEC), EHEC, or Shiga toxin producing E. coli (STEC), enteroaggregative E. coli (EAEC), and diffusely enteroadherent E. coli (DAEC). A comprehensive overview of these groups of E. coli is presented in Table 1.1.

Diagnosing the causative agent in individuals is challenging (other than conditions like epidemic outbreaks) because the disease is mostly self-limiting within days and the procedures for detecting the toxins, pathogenic genes, and cytotoxicity through immunoassays, DNA hybridization, cell culture, and adherence assays are done mostly for severe cases.

1.2.1 Enteropathogenic E. coli (EPEC)

EPEC is one of the most important causes of acute diarrheal illness in infants and children worldwide. EPEC was found to be a major cause of pediatric diarrhea both in community and hospitalized patients (Lanata et al. 2002). The bacteria spread through fecal-oral route, either directly or indirectly, by consuming contaminated food or water. The infective dose is low and is less than 10,000 colony-forming units (cfu).

Table 1.1 Comprehensive Overview of the Clinical Profiles of Each type of Escherichia coli

DAEC, diffusely enteroadherent E. coli; EAEC, enteroaggregative E. coli; EHEC, enterohemorrhagic E. coli; EIEC, enteroinvasive E. coli; EPEC, enteropathogenic Escherichia coli; ETEC, enterotoxigenic E. coli; HUS, hemolytic uremic syndrome; LT, labile toxin; ST, stable toxin; STEC, Shiga toxin producing E. coli.

1.2.1.1 Pathogenesis

EPEC possesses a localized adherence pattern with the help of their fimbriae. This property is governed by a unique pathogenicity associated island (PAI) termed as locus for enterocytes effacement (LEE). Activation of LEE during contact with enterocytes forms type III secretary system (T3SS) through which bacterial effector molecules is injected into the enterocytes via a pilus-like structure. These effector molecules then initiate a cascade of events like disruption of gap junction, release of interleukin-8 (IL-8), adenosine and disruption of sodium chloride (NaCl)-mediated transport mechanisms leading to diarrhea. Based on the pathogenesis, they are classified into two groups namely typical EPEC (tEPEC) and atypical EPEC (aEPEC). tEPEC has classical pilus formation with attaching effacing lesions, whereas the aEPEC form has atypical adherence pattern. Atypical form appears to be more important and common pathogen than the typical form (Nguyen et al. 2006).

1.2.1.2 Clinical features

EPEC causes watery diarrhea with vomiting and dehydration in infants and children. The incubation period is usually 1–2 days. The diarrhea is often self-limiting, but EPEC are strongly associated with severe and persistent diarrhea in some cases.

1.2.1.3 Diagnosis

Typically targeting the virulence genes by polymerase...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• Series Preface
• Editors
• Contributors
• 1 Bacteria Causing Gastrointestinal Infections: Overview of Types of Bacteria Causing Gastrointestinal Infections, Mode of Infection, Challenges in Diagnostic Methods, and Treatment
• 2 Gateways of Pathogenic Bacterial Entry into Host Cells—Salmonella
• 3 Prevalence of Bacterial Infections in Respiratory Tract
• 4 Oral Health: A Delicate Balance between Colonization and Infection
• 5 Bacterial Infections in Atherosclerosis: Atherosclerosis Microbiome
• 6 Neonatal Bacterial Infection: Insights into Pathogenic Strategy and Onset of Meningitis and Sepsis
• 7 Bacterial Infections of the Oral Cavity: Bacterial Profile, Diagnostic Characteristics, and Treatment Strategies
• 8 Prognosis and Impact of Recurrent Uveitis, the Ophthalmic Infection Caused by Leptospira Spp.
• 9 Beneficial Lactic Acid Bacteria: Use of Lactic Acid Bacteria in Production of Probiotics
• 10 Role of Bacteria in Dermatological Infections
• 11 Bacteriology of Ophthalmic Infections
• 12 Role of Bacteria in Urinary Tract Infections
• 13 Role of Bacteria in Blood Infections
• Index