Multidrug-resistant Germs: Causes

Pathogenesis (development of disease)

Multidrug-resistant problem germs are:

  • New Delhi metallo-β-lactamase 1 (NDM-1) strains: involves bacterial strains (gram-negative enterobacteria Escherichia coli and Klebsiella pneumoniae) with the NDM-1 gene that are reported to be resistant to all antibiotics known to date, with the exception of tigecycline and colistin.
  • Methicillin-resistant Staphylococcus aureus (MRSA) strains: involves Staphylococcus aureus strains that have the mecA gene, which encodes an altered penicillin-binding protein PBP2a with a greatly reduced affinity for beta-lactam antibiotics and thus are resistant to all beta-lactam antibiotics (including. including against so-called beta-lactamase-solid AB: methicillin, oxacillin flucloxacillin, and others so-called staphylococcal antibiotics / beta-lactam antibiotics) are resistant.
  • Vancomycin-intermediate-sensitive Staphylococcus aureus (VISA) strains: concerns MRSA strains that are also intermediate-sensitive to glycopeptides.
  • Vancomycin-resistant Staphylococcus aureus (VRSA) strains: these, unlike VISA strains, possess the glycopeptide resistance-encoding vanA gene derived from vancomycin/glycopeptide-resistant enterococci (VRE/GRE).
  • Carbapenem-resistant Klebsiella pneumoniae (KPC) strains: involves a specific Klebsiella pneumoniae strain that produces a carbapenemase (carbapenem-hydrolyzing beta-lactamase) called KPC. This causes resistance to carbapenems (imipenem, meropenem). In the presence of clavulanic acid, the activity of carbapenemase is suppressed.
  • Extended spectrum β-lactamase (ESBL)-producing pathogens: involves bacteria that are able to produce extended spectrum β-lactamase due to a point mutation within the genes expressing the β-lactamase enzyme. ESBL-bearing pathogens are thus resistant to penicillins, cephalosporins (generation 1-4), and monobactams.
  • Other problem germs:
    • Multi-resistant gram-positive bacteria (MRGP/MDRGP):
      • Clostridium difficile (life-threatening diarrheal disease).
      • Mycobacterium tuberculosis (causative agent of multidrug-resistant tuberculosis; MDR-TB).
      • Vancomycin/glycopeptide-resistant enterococci (VRE, GRE).
      • Penicillin-resistant pneumococci
    • Multi-drug resistant gram-negative bacteria (MRGN/MDRGN):
      • Acinetobacter baumannii
      • Bacteria of the genus Campylobacter
      • Bacteria of the genus Salmonella (Salmonella anatum, Salmonella choleraesuis, Salmonella saintpaul, Salmonella typhimurium) (causative agents of diarrheal diseases).
      • Indole-positive strains of the bacterium Proteus mirabilis.
      • Pseudomonas aeruginosa (most common hospital germ in Germany).
      • Some serogroups of enterohemorrhagic Escherichia coli bacteria (EHEC) (esp. the pathogen strain HUSEC 41 of sequence type ST678, also called stereotype O104).
    • Other multi-drug resistant pathogens:
      • Unicellular parasites of the genus Plasmodium.
        • Plasmodium falciparum (malaria tropica).
        • Plasmodium vivax or Plasmodium ovale (malaria tertiana).
        • Plasmodium malariae (malaria quartana)

Risk factors for the risk of acquiring multidrug-resistant germs are listed below.

Etiology (causes)

Biographic causes

  • Age – increasing age (wg senile immunodeficiency).
  • Socioeconomic factors – low socioeconomic standard.
  • Occupations – occupations in agriculture

Behavioral causes

  • Nutrition
    • Malnutrition or malnutrition
  • Pleasure food consumption
    • Alcohol
    • Tobacco (smoking)
  • Poor hand hygiene: one in four patients carried multidrug-resistant pathogens (MREs) on their hands when admitted to a U.S. rehabilitation facility.
  • Hospital
    • More common in shared rooms than in single rooms: Risk of vancomycin-resistant enterococci infection from moving from a multibed to a single room reduced by 70%.
  • Foreign travel (esp. Southeast Asia, the Western Pacific, the Middle East, and Sub-Saharan Africa):
    • Of 574 travelers who were free of multidrug-resistant pathogens before traveling to tropical countries, half returned with multidrug-resistant pathogens in their intestines.
    • India returnees returned with multidrug-resistant bacterial strains in their gut in 76% of cases, including colistin-resistant strains containing the mcr-1 gene.

Disease-related causes

  • Chronic skin diseases that lead to skin defects (e.g. psoriasis (psoriasis), eczema).
  • Diabetes mellitus
  • Immunodeficiency (immune deficiency)/immune defect

Medication

Surgeries

  • Surgical procedures of any kind

Environmental pollution – intoxications (poisoning).

  • Food industry: intensive livestock farming (factory farming) using antibiotics with admixture to animal feed.

Other causes

  • Iatrogenic:
    • Frequent and often unnecessary use of antibiotics.
    • Antibiotic use without prior bacteriology (determination of the pathogen or its resistance).