[Risk factors for gastrointestinal colonization by ESBL-producing Klebsiella pneumoniae and Escherichia coli in anaesthesiology and reanimation intensive care unit]

Risk factors for fecal carriage of extended-spectrum beta-lactamase-producing and carbapenem-resistant Escherichia coli and Klebsiella pneumoniae strains among patients at hospital admission

AIM

Extended-spectrum beta-lactamase (ESBL)-producing and carbapenem-resistant (CR) Enterobacteriaceae are substantial problems in hospital-acquired infections worldwide. We analyzed the risk factors for fecal carriage of ESBL-positive and/or CR E. coli and K. pneumoniae (EcKp) strains in a hospital in Turkey, an endemic country for both resistances.

MATERIALS AND METHODS

A prospective cross-sectional study including the rectal swab samples of 168 patients, obtained at the day of admission, was conducted. ESBL-producing and CR EcKp were investigated with phenotypic tests and PCR, and the clonal relatedness of isolates was studied. Risk analysis was performed with logistic regression method.

RESULTS

A total of 67 (39.8%) and 21 (12.5%) patient samples tested positive for ESBL-producing and CR EcKp, respectively. CTX-M (n = 27) and OXA-48 (n = 12) were the dominant ESBL and carbapenemase types, and 4.5%-10.7% of the isolates were clonally-related. Among 15 potential risk factors studied, longer lengths of hospital stay and antimicrobial use, and receiving total parenteral nutrition in the last 6 months were determined as independent risk factors for fecal carriage of ESBL-producing and/or CR EcKp, while prior antimicrobial treatment was only a risk factor for ESBL producers.

CONCLUSION

Certain conditions in patients' medical backgrounds may be associated with increased likelihood of resistant bacterial colonization. Notably, questioning these situations at admission can help to identify potential carriers and proactively administer appropriate infection control measures.

The Characteristic of Virulence, Biofilm and Antibiotic Resistance of Klebsiella pneumoniae

Klebsiella pneumoniae is an important gram-negative opportunistic pathogen that causes a variety of infectious diseases, including urinary tract infections, bacteremia, pneumonia, and liver abscesses. With the emergence of multidrug-resistant (MDR) and hypervirulent K. pneumoniae (hvKP) strains, the rapid spread of these clinical strains in geography is particularly worrying. However, the detailed mechanisms of virulence and antibiotic resistance in K. pneumoniae are still not very clear. Therefore, studying and elucidating the pathogenic mechanisms and drug resistance mechanism of K. pneumoniae infection are important parts of current medical research. In this paper, we systematically summarized the virulence, biofilm, and antibiotic tolerance mechanisms of K. pneumoniae, and explored the application of whole genome sequencing and global proteomics, which will provide new clues for clinical treatment of K. pneumoniae.

A prospective surveillance study for multidrug-resistant bacteria colonization in hospitalized patients at a Thai University Hospital

Background

Colonization with multidrug-resistant (MDR) bacteria is a major risk factor for developing subsequent MDR infections.

Methods

We performed a prospective surveillance study in hospitalized patients at Siriraj Hospital. Nasal cavity, throat, inguinal area and rectal swabs were obtained within the first 48-h after admission, on day-5 after hospitalization and then every 7 days until discharge. Target bacteria included extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL), carbapenem-resistant-P.aeruginosa (CR-PA), carbapenem-resistant-A.baumannii (CR-AB) and methicillin-resistant S.aureus (MRSA).

Results

From January 2013–December 2014, 487 patients were enrolled. The baseline prevalence of colonization by ESBL, CR-PA, CR-AB and MRSA at any site was 52.2%, 6.8%, 4.7% and 7.2%, respectively. After 3-week of hospitalization, the prevalence of colonization by ESBL, CR-PA, CR-AB and MRSA increased to 71.7%, 47.2%, 18.9% and 18.9%, respectively. Multivariable analysis revealed that diabetes mellitus and recent cephalosporin exposure were the independent risk factors for baseline colonization by ESBL. The independent risk factors for CR-AB and/or CR-PA colonization were cerebrovascular diseases, previous hospitalization, transfer from another hospital/a LTCF and previous nasogastric tube use, whereas those for MRSA colonization were previous fluoroquinolone exposure and previous nasogastric tube use.

Conclusions

The baseline prevalence of colonization by ESBL was relatively high, whereas the baseline prevalence of colonization by CR-PA, CR-AB and MRSA was comparable to previous studies. There was an increasing trend in MDR bacteria colonization after hospitalization.

Predominance of Klebsiella pneumoniae ST14 carrying CTX-M-15 causing neonatal sepsis in Tanzania

Background

Klebsiella pneumoniae strains expressing ESBLs are a predominant cause of hospital acquired infections. Here we describe the molecular epidemiology of these isolates in a tertiary hospital in Tanzania, as potential pathogens for neonatal infections.

Methods

Between April 2009 and March 2010 all Klebsiella pneumoniae isolates with phenotypic expression Extended Spectrum Beta Lactamase (ESBL) were collected and characterized. Identification was done using in house biochemical tests in case of ambiguous results confirmation was done using API 20E. Susceptibility testing was determined using the disc diffusion method followed by specific PCR and sequencing to determine ESBL genes. Phylogenetic analysis, Pulse field gel electrophoresis (PFGE) and Multi-Locus sequence typing (MLST) to PFGE clusters representative isolates were performed to determine clones of the isolates. Conjugation and hybridization were performed to determine the location of blaCTX-M-15 gene.

Results

A total of 92 non- repetitive ESBL producing K. pneumoniae representing 50.3% of Klebsiella pneumoniae isolates were characterized. These isolates were from blood 61 (66%), wound swab 13 (14%), urine 12 (13%) and pus 6 (7%) were analyzed. Most blood culture strains originated from neonatal unit 39/61(64%) and 22 (36%) of the blood culture isolates were from neonatal ICU. All isolates were resistant to gentamicin and 54% were resistant to ciprofloxacin. Using a similarity index of 80%, the isolates were assigned to thirteen clusters based on PFGE patterns and contained sub-clusters with identical strains indicating clonal outbreaks. Cluster X5, X7 and X8, and X9 were grouped into ST48, ST14 and ST348 respectively. Based on gyrA PCR- RFLP phylogenetic analysis all isolates were grouped as KpI. The predominant ESBL allele detected was bla_CTX-M-15 which was found in 76% of isolates, followed by bla_TEM-104 (19%), bla_SHV-11 (3.2%) and bla_TEM-176 (2%). The bla_CTX-M-15 gene was located in multiple conjugative IncF plasmids ranging from 25 kb-485 kb in size.

Conclusion

The high prevalence of bla_CTX-M-15 observed among ESBL producing K. pneumoniae in Tanzania, is possibly due to the spread of a common IncFII 145 kb plasmid and of certain clones such as ST14 and ST48. Furthermore the 485 kb plasmid detected is the largest plasmid reported to carry bla_CTX-M-15 todate.