Klebsiella pneumoniae is an opportunistic pathogen responsible for causing various community acquired and healthcare associated patients. Further infection caused by this bacterium cannot be neglected as it is included in ESKAPE pathogens and the growing incidence of CRKP strains creates attention to clinicians and other stake holders.
In our study, the highest percentage of K. pneumoniae was obtained from the in-patient department than others. This higher incidence of K. pneumoniae in long-term hospitalized patients may be related to the immune status of the patients, as the bacterium was from surgery unit having use of invasive devices and administration of immunosuppressive drugs. In hospital settings, the transmission of the pathogen increases drastically because colonization rate increases with extended stay in hospital and prolonged antibiotic therapy. A similar study carried out in the United States also claimed a higher incidence of K. pneumoniae infections in the long-term acute care hospitals than in the short-term hospital stay.
Antibiotic resistance is a common problem in K. pneumoniae. It is naturally resistant to penicillin group of antibiotics or acquires resistance gene from mobile genetic cassettes called integrons often carried out by transposons and transferable plasmids that transmit horizontally to receptor cells, integrated on plasmids or chromosomes through homologous recombination, expressing its fitness in the presence of antibiotics . In this study, we evaluated 12 different antibiotics in which amikacin, gentamicin, ciprofloxacin, ofloxacin, ceftriaxone and ertapenem were tested in all isolates and rest antibiotics were tested either as second-line antibiotics or depend on a source of clinical samples. Our results showed a mixed antibiotic resistance profile comparison with others in terms of using antibiotic use, time period, source of bacterium and country.
Approximately 48.24% and 56.47% isolates were non-susceptible to aminoglycoside amikacin and gentamicin, respectively. A range of studies show greater variation in resistant pictures ranging below 1–86% for gentamicin. A study in the EU/EEA region showed that its resistant percent ranges from below 1% to greater than 50 . A comparative study from France and Algeria revealed that its resistance was 28% and 86%, respectively while study from Iran and India, its resistance was found as 24% and 37.5%, respectively [20, 21]. A slightly higher percentage, 41%, was pictured from Nepal  that is nearly equal to our study. Cephalosporins like ceftriaxone are frequently used antibiotics for K. pneumoniae until unless they are ESBL producers. Our study showed that nearly 70% of isolates were ceftriaxone resistant. A similar finding was reported from Ethiopia  and 4 year consecutive study from Greece . Ciprofloxacin and ofloxacin are alternative antibiotic of choice if the isolates are ESBL producers. The non-susceptibility rates of ciprofloxacin and ofloxacin were 57.65% and 55.3% in our study. Similar to aminoglycosides, a wider range of variation was observed in the non-susceptibility of quinolones ranging from below 1% to greater than 90%. The study from Bulgaria, Italy and Romania was in line with our study, while from countries like Germany, Denmark, Iran, and India, the non-susceptibility rate was lower than our study [18, 20, 21]. Few studies from Nepal showed that the resistance rate is more than 85%, which is quite much than ours [22, 24]. Over all different studies on different times showed marked variation in antibiotic resistance patterns. Such type of variation was also observed in other antibiotics mentioned in Table 1, which might be due to the low number of sample studies or how meticulously antibiotics were used in that country to mitigate antibiotic resistance problems. Hence, resistance to these first-line agents represents an unprecedented challenge to clinicians, scientists, and healthcare systems.
Carbapenem (imipenem, meropenem, and ertapenem) are the antibiotics of choice for MDR and ESBL producing K. pneumoniae . The phenotypic lab detection of carbapenem resistance is quite confusing and should perform different test panels ; hence, CLSI recommends that non-susceptibility to ertapenem is the most sensitive indicator of carbapenemase producers and those addition tests need not be done other than epidemiological or infection control purposes after breakpoint evaluation of ertapenem, meropenem and imipenem . In our study, 49 (both intermediate and resistant) isolates showed screening test positive through ertapenem nonsusceptibility. This suggests that carbapenem resistance arises due to the formation of carbapenemase enzymes of classes A, B and D of the Amber class of β-lactamase restricting the treatment option . The CRKP was subjected to E-test to determine MIC of imipenem. The test results showed susceptible, intermediate and resistant were 13 (MIC ≤ 1 µg/ml), 5 (4 µg/ml ≤ MIC ≥ 1 µg/ml) and 31 (MIC ≥ 4 µg/ml), respectively. This implies that results from phenotypic methods can vary, as suggested by CLSI.