Relative abundance of extended spectrum beta-lactamase enzyme (ESBLs) in Klebsiella pneumoniae isolated from patients hospitalized in Yazd hospitals by Double Disk Synergy Test method

Dissertation for general doctorate degree

Abstract

Introduction and purpose: Since 1980, new groups of antibiotics called oxyamines and cephalosporins, which were resistant to the hydrolytic activity of beta-lactamases, were used to treat Gram-negative bacterial infections. In the early 1990s, extended-spectrum beta-lactamases (ESBLs) produced by Gram-negative bacteria showed resistance to cephalosporins such as ceftazidime and cefotaxime, and the resistance to cefotaxime was greater than that of ceftazidime. Due to the fact that the resistance of Enterobacteriaceae species to antibiotics due to having ESBLs is increasing and their prevalence is different in different countries, regions and even hospitals, we decided to investigate the prevalence of this enzyme in the samples collected from Yazd teaching hospitals using the Double Disk Synergy Test method. Materials and methods: The studied population of Klebsiella strains Pneumonia was obtained from patients hospitalized in university hospitals of Yazd province in March 2019 to March 2019. This study is a cross-sectional descriptive-analytical study, and Klebsiella pneumoniae isolates were identified using common biochemical tests, and sensitivity to antibiotics was measured by disk diffusion method, and the Double Disk Synergy Test was used to confirm the presence of ESBLs in the strains.

Results: In this study, 118 Klebsiella pneumoniae isolates was investigated. 38 samples (32.2%) of all isolates were ESBLs producers. The frequency of Klebsiella pneumoniae isolates producing ESBLs was found in urine (27.7 percent), wound and blood and catheter (23.8 percent) and secretions (ear, nose and throat, lung and CSF) and sputum (46.9 percent), respectively. The highest prevalence of ESBLs was in the intensive care unit (39.1 percent).

There was no significant relationship between age ranges, gender, sample type and the type of ESBLs botulinum toxin by Klebsiella pneumoniae isolates (P.value> 0.05).

Klebsiella pneumoniae strains were the most resistant to ampicillin (92.4%), cefotaxime (60.2%) and showed cotrimoxazole (55.1%). Also, Klebsiella pneumoniae strains were most sensitive to imipenem (77.1%), piperacillin (69.5%) and ciprofloxacin (66.1%) antibiotics. The status of resistance to antibiotics was significant with P-Value=0.000.

Conclusion: In this study, no significant relationship was found between age, sex, and ward type with the abundance of ESBLs enzyme. The highest prevalence of this enzyme was found in ear, pharynx, and nasal secretions, and the highest prevalence of ESBLs was in the intensive care unit (39.1 percent).

The highest antibiotic resistance was to ampicillin, cefotaxime, and cotrimoxazole, respectively, and the highest sensitivity to imipenem, piperacillin, and ciprofloxacin. According to the obtained results and the high resistance of these isolates, it is suggested that, apart from emergency cases, before the use of antibiotics, antibiotic sensitivity tests should be performed and the detection of the presence of these enzymes in medical laboratories should be made common. rtl;">Enterobacteriaceae

Enterobacteriaceae are the largest heterogeneous group of Gram-negative bacilli in medicine, of which about 40 genera and 150 species have been identified. This collection is part of the normal intestinal flora of most animals and humans. In humans, these bacteria are responsible for 30-35% of septicemias, more than 70% of urinary infections and many intestinal infections. Some of their types include E.Coli, Klebsiella, Proteus, Salmonella and Shigella. All members of the Enterobacteriaceae group grow in aerobic and anaerobic conditions[1].

1-2- Klebsiella

Klebsiella is a rod-shaped, non-motile gram-negative bacterium with a polysaccharide capsule that covers the entire cell surface and is against many host defense mechanisms.

1-2- Klebsiella

Klebsiella is a rod-shaped, non-motile gram-negative bacterium with a polysaccharide capsule that covers the entire surface of the cell and creates resistance against many host defense mechanisms. The members of the Klebsiella genus express two types of lipopolysaccharide (o antigen) and capsular polysaccharide (k antigen) antigens on the surface of their cells[2].

1-3- History

Klebsiella genus is a member of the Klebsiella family and of the Enterobacteriaceae family. In the 19th century, this organism was discovered by Edvin Klebs, and therefore it was called Klebsiella, which is derived from the name of this German microbiologist[2].

The capsule in Klebsiella is a polysaccharide (cps) that covers the entire surface of the cell and provides bacterial resistance against many host defense mechanisms, which prevents phagocytosis and has weak antigenic properties and plays a role in connecting bacteria to the host.

2. Pili or fimbriae

Fimbriae are protrusions on the surface of bacteria that cause the organism to stick to the respiratory system, gastrointestinal system, and mucous cells of the urinary system.

3. Siderophores

Many bacteria host iron-chelating substances with low molecular weight and high affinity called They secrete siderophores, which are able to competitively absorb iron bound to proteins.

4. Toxin

Enterotoxin producing strains have been isolated from patients with tropical sparrow[1]. This toxin is similar to LT[2] and ST[3] toxins in E.coli. In K.pneumoniae strains, the production of enterotoxin is dependent on the plasmid [2].

1-5- Location of the Klebsiella microbe

The usual place of colonization of this bacterium in healthy humans is the gastrointestinal tract, eyes, respiratory tract, and urogenital tract. K.pneumoniae exists as a saprophytic microorganism in the human nasopharynx and gastrointestinal tract. Since there are no suitable conditions for the growth of Gram-negative bacteria on the human skin, Klebsiella is rarely observed in that area and is considered as a temporary flora. Klebsiella is one of the intestinal bacilli. In general, when these bacteria live in the intestine, they live side by side. Therefore, their settlement in this place is considered a reservoir or a source for contamination and production of disease in other places, including the lungs and urinary tract[2].

Klebsiella clinical diseases:

Klebsiella genus has several species. The most important of them is K.pneumoniae, which was previously known as the cause of classic lobar pneumonia.

K.pneumoniae: the cause of pneumonia (causes congestion in the lungs with necrosis and severe bleeding, which alcoholics and people with lung clearance disorders are more prone to pneumonia), sepsis (the main cause of septicemia in children's hospital departments), hospital infections and urinary tract infections.

K.ozaenae: is the cause of atrophic rhinitis, which causes foul-smelling and progressive atrophy of the nasal mucous layer.

K.scleromatis: found in patients with rhinoscleroma (a destructive disease of granuloma of the nose and pharynx).

K.oxytoca: the cause of hospital infections that occur in First, it is divided under the name Klebsiella pneumoniae endole positive.

K. planticula: It is an environmental organism, but it participates in urinary tract infections and wound infections.

K. granolomatis: It is the cause of inguinal granuloma, which creates granulomatous ducts on the inguinal and genital area[2].

1-6- Hospital infection (Nosocomial Infection) and K.pneumoniae

The term nosocomial or infection acquired from the hospital refers to the occurrence of a new disease (unrelated to the patient's main illness), following the person's treatment in the hospital [3].