: MS Word : 1-5 : 131 : Abstract
 Price: Just #2000
Get the complete project ยป

BIO00186 - PLASMID PROFILING OF MULTIDRUG-RESISTANCE CLINICAL ISOLATES OF KLEBSIELLA PNEUMONIAE


CHAPTER ONE

  • INTRODUCTION

1.1 Klebsiella pneumoniae 

Burns infections and urinary tract infections are the most important prevalent diseases in Asian countries, such as Iraq. K. pneumoniae is one of the most important bacteria that cause this type of infections especially in hospitals. K. pneumoniae is a Gram negative, rod-shaped bacillus from the genus Klebsiella and family Enterobacteriaceae (Boone et al., 2001). K. pneumoniae is a facultatively anaerobic, oxidase-negative, and produces acid and gas from lactose. It is an enteric bacterium, noted in the intestinal tract of 5% of healthy humans (Ganaway, 2004). The genus is named for German physician and bacteriologist Edwin klebs.

  1. pneumoniae, also called Friedlander’s bacillus, was first described in 1992 by German microbiologist and pathologist Carl Friedlander. K. pneumoniae is best known as pathogen of the human respiratory system that causes pneumonia. The disease is usually seen only in patients with underlying medical problems such as alcoholism or chronic pulmonary disease and often arises as a nosocomial infection (infection occurring in association with invasive treatment or long-term care in hospitals or other community health care settings). K. pneumoniae is an important opportunistic pathogen that causes a variety of infectious diseases in humans, including septicemia, liver abscesses, diarrhea and pneumonia. It is a well- known hospital acquired pathogen and associated with increased patient morbidity and mortality (Brisse et al., 2009; Cabral et al., 2012). In addition to the clinical environment, K. pneumoniae is frequently found in foods, including raw vegetables, powered infant formula, meat, fish and street foods, and has been considered as an important food-borne pathogen. In powered infant formula, K. pneumoniae is included in the hazard identification category “B” according to the Food and Agriculture Organization (FAO) and World health Organization (WHO) guidelines on microorganisms (FAO-WHO, 2004). In recent years, an increasing number of food-borne outbreaks caused by K. pneumoniae have been reported in different countries (Calbo et al., 2011; Zhou et al., 2011; Bi and Xu, 2013). Importantly, K. pneumoniae colonizes man mucosal surfaces, including the gastrointestinal tract and oropharynx where the effect of its colonization appears benign. From these sites, K. pneumoniae strains can gain entry to other tissues and cause severe infections in humans. K. pneumoniae is an extremely resilient bacterium whose success as a pathogen seems to follow the model of “the best defense for a pathogen is a good defense”” rather than “the best defense for a pathogen is a good offense”. This is exemplified by the ability of these bacteria to evade and survive, rather than actively suppress many components of the immune system and grow at many sites in hosts.
  2.   pneumoniae is one of the most important multidrug-resistance (MDR) opportunistic Gram-negative bacteria that cause different illness with high mortality and morbidity due to hospital-acquired infections and non-hospital acquired infections such as pneumonia, Urinary tract infection (UTI), burns infections and bacteremia (Lee et al., 2016).  K. pneumoniae, the most common Klebsiella species causing human infections, is one of the top three pathogens of international concern documented in the 2014 World health organization(WHO) Global report on surveillance of Antimicrobial resistance (WHO, 2014).  Because they are responsible for a large variety of infections and are becoming resistant to many, if not sometimes to all antibiotics available today, they have been recognized, together with a group of pathogens, to be a threat to public health by the WHO. However, despite their clinical importance, many facets of the pathophysiology of K. pneumo niae remain unknown. We are interested in understanding the mechanisms used by these bacteria to cause infections and how they interact with the infected host (Aljanaby, 2013). This bacterium colonizes a wide range of hosts ranging from plants to mammals, but can also be found in the soil and surface water (Podschin et al., 2001). Normally, individuals carry K. pneumoniae asymptomatically on the skin, in the nose and throat (Bagley, 1985). There are different mechanisms for the development of resistance in Klebsiella sp. including the acquisition of plasmids which code for the production of Extended-Spectrum Beta-Lactamases(ESBL) and aminoglycoside modifying enzymes. The genetic origin of drug resistance maybe plasmid or chromosomal. Plasmids carry genes for resistance to often more than one antibiotics, these plasmids so-called R-plasmids. R-plasmids can easily transfer between different species and even genera of bacteria, so, determination of the genetic origin of resistance in clinical isolates of bacteria can predict the rate of transferring resistance between clinical isolates (Oktem et al., 2008).

           Notably, the selective pressure posed by the extensive use of antibiotics has facilitated the emergence of Multidrug-resistant (MDR) K. pneumoniae. Furthermore, conjugation transmission of antibiotic resistance genes across bacterial species and genera has aggravated the problem of K. pneumoniae. MDR K. pneumoniae was reported in the United States, followed by Europe, South Africa and Asia (Koo et al., 2002; Pfaller et al., 2001; Winokur et al., 2001; Yigit et al., 2001). At present, infections caused by MDR K. pneumoniae have become a major problem, as few antibiotics are available, resulting in higher morbidity, longer hospitalization, increased mortality rates, and excessive health care costs compared with infections associated with antibiotic-susceptible micro organisms (Correa et al., 2013; Ma and Wang, 2013).

  1.   pneumoniae has emerged as the most common organism in Polylactic acid (PLA), which can lead to serious complications including bacteremia and extrahepatic abscesses (Lederman and Crum, 2005; Pope et al., 2011). Multidrug combination therapy and some alternative treatment options are required to control the infections associated with this microorganism. Due to the associated side effects and failure of drug treatment therapy, alternative and complementary therapy approaches are the preferred treatment strategies. Recently, an alternative treatment approach using healing therapy or therapeutic touch known as biofield energy treatment, which has been widely reported in various research fields. The biofield therapies (putative energy fields) were reported to alter the sensitivity of antimicrobial against treated microorganisms (Trivedi et al., 2005), phenotypic and biotypic characterization of K. pneumoniae. An impact of biofield treatment inhibits the growth of bacterial cultures, effect on in vitro cells, tissues, animals, and the clinical effects, healing rates of wounds, e.t.c. Recently, K. pneumoniae became more resistant to antimicrobials especially the third generation Cephalosporins and many studies focused on isolation of this pathogen from patients infected with different infections. K. pneumoniae is one of the most Enterobacteriaceae strains that can produce Extended-spectrum Beta- Lactamases Enzymes (ESBLs) and become highly effective against different beta-lactam antimicrobials. On the other hand, ESBL producing bacteria are resistance to various antimicrobials classes, lead to difficult to treat diseases and called MDR bacteria. (Anderl et al., 2000). Multidrug-resistance bacteria and ESBL producing K. pneumoniae and other Gram negative bacteria have worldwide distributions with high degree of prevalence in both hospitals and community (Barguigua et al., 2011).

            Moreover, MDR and ESBL producing K. pneumoniae strains isolated from both inpatients and outpatients can cause treatment failure with different antimicrobials therapy such as beta-lactam, Cephalosporins, and others. Antimicrobial resistance is a global problem, and K. pneumoniae is recognized as a major pathogen of hospital-acquired infections. In the past several years, Chinese clinicians have witnessed a remarkable increase in the drug resistance rate of K. pneumoniae strains isolated from clinical settings (Qi et al., 2011; Hu et al., 2016). Now a substantial portion of hospitalized patients are colonized by these pathogens causing outbreaks of nosocomial infections in various regions across the country (Paczosa and Mecsas, 2016). K. pneumoniae is now seen as one of the major pathogenic bacteria of British standard institutions (BSIs), accounting for 11.3% between 2011 and 2012 in china (Lv et al., 2014). The aim of this study was to investigate the prevalence of multidrug-resistance K. pneumoniae (Abrar and Vajeeha, 2017). The continued emergence of antibiotic resistance in K. pneumoniae, and more broadly Enterobacteriaceae, presents a considerable clinical challenge. The steep decline in the discovery of effective antibiotics by pharmaceutical companies further exacerbates the threat posed by MDR pathogens. Rapid, accurate detection and characterization of antimicrobial resistance determinants and genomic mutations conferring resistance are crucial to countering the mounting burden of infections caused by MDR bacteria. Such information could help direct hospital resources to prevent nosocomial spread of MDR organisms and guide best-choice antimicrobial therapy to improve patient outcomes. (Pecora et al., 2015).

  • CHARACTERISTICS OF pneumoniae

Klebsiella pneumoniae is a Gram-negative, non-motile, encapsulated, lactose fermenting, facultative anaerobic, rod-shaped bacterium. It appears as a mucoid lactose fermenter on MacConkey agar. The Gram-negative rod measures 0.3~ 1.0µm in diameter and 0.6~6.0µm long. It can exist alone or in pairs or in the form of short chain. The bacterium is surrounded by a prominent polysaccharide capsule imparting a mucoid appearance to the colonies which can be used for serologic identification, but molecular serotyping may replace this method (Brisse et al., 2004). Klebsiella spp are found both in natural environment and clinical settings. In the environment, they are distributed in soil, surface water, sewage and on plants (Wang et al., 1985). The other sources where the pathogen colonizes are the mucosal surfaces and guts of mammals such as human, horses and swine. It naturally occurs in the soil, and about 30% of strains can fix nitrogen in anaerobic conditions (Postgate, 1998). The optimum temperature for growth of K. pneumoniae is 30-35°C and at pH 7.2. As a free living diazotroph, its nitrogen-fixation system has been much studied, and is of agricultural interest, as K. pneumoniae has been demonstrated to increase crop yields in agricultural conditions.

            Although found in the normal flora of the mouth, skin and intestines (Ryan and Ray, 2004), it can cause destructive changes to human and animal lungs if aspirated (inhaled), specifically to the alveoli (in the lungs) resulting in bloody sputum. In the clinical setting, it is the most significant member of the Klebsiella genus of the Enterobacteriaceae. In recent years, Klebsiella species have become important pathogens in nosocomial infections. Members of the genus Klebsiella typically express two types of antigens on their cell surfaces. The first, O antigen, is a component of the Lipopolysaccharide (LPs) of which 9 varieties exist. The second is K antigen, a capsular LPs with more than 80 varieties (Podschun and Ullmann, 1998). K. pneumoniae is commonly found in the gastrointestinal tract and hands of hospital personnel. It is 160nm thick of fine fibres that protrude out from the outer membrane at the right angles (Lawlor et al., 2005).

       The widespread development of resistance to several different antibiotics is generally as a result of lateral or horizontal gene transfer. Many studies have demonstrated that plasmid transfer between bacteria occur in diverse environments (Kaper et al., 2004; Kramer et al., 2006; Kuhnert et al., 2011). Various diverse phenotypic characteristics are encoded by plasmids; these include antibiotic and metal resistance, degradation of complex organic compounds, and the production of restriction enzymes. Most of the transfers are described using bacteria from the same group of ecological niche. Plasmids size range from 1kpb to 2,000 kpb. Gram-negative bacilli causing nosocomial infections are usually multiple- antibiotic resistant, resulting in significant problems for treatment.

  •      JUSTIFICATION FOR THE STUDY

            There is a high rate of emergence and dissemination of antibiotic resistance in bacteria which is alarming to humans and animals’ health ( Alanis, 2005; Da silva and Mendonca, 2012; Hawkey and jones, 2009; Rice, 2012). Heavy use of antibiotics by human has been reported to be the prime mover behind this resistance problem (Aarestrup et al., 2008). The proliferation of antibiotic resistant bacteria possesses a significant threat to human health because most of these organisms are pathogenic possessing some factors like plasmids, toxins, etc. In human, when infections become resistant to antibiotic treatments, morbidity is prolonged thereby increasing mortality and facilitating the spread of the resistant pathogens.

            Furthermore, prolonged hospitalization and use of last generation antibiotics inflate patient’s hospital bill (McDonald, 2006; Rice, 2009). This issue of antibiotic resistance is more severe in developing countries where resources are limited and there are no effective check and surveillance mechanisms for antibiotic usage (Collignon, 2009; Kennedy et al., 2008; Laupland et al., 2008).

  • AIMS AND OBJECTIVES
    • Aims
  • The aim of this study is to determine the plasmid profiling of multidrug-resistance clinical isolates of pneumoniae.

1.4.2    Objectives of the study

The specific objectives include:

  • To determine the resistance pattern of pneumoniae to selected antibiotics.
  • To analyze the plasmid profile of multi drug resistance clinical isolates of pneumoniae.