Epidemiology of carbapenem-resistant Klebsiella pneumoniae colonization: a surveillance study at a Turkish university hospital from 2009 to 2013

Incidence and risk factors for subsequent infections among rectal carriers with carbapenem-resistant Klebsiella pneumoniae: a systematic review and meta-analysis

BACKGROUND

Carbapenem-resistant Klebsiella pneumoniae (CRKp) is a major pathogen causing nosocomial infections with a high mortality and poor prognosis. Gastrointestinal carriage has been acknowledged as the primary reservoir of CRKp infections.

AIM

To explore the incidence and risk factors associated with CRKp infection following colonization.

METHODS

The PubMed, Web of Science, and Cochrane Library databases were searched for relevant articles published between December 1998 and June 2023. Pooled estimates with a 95% confidence interval (CI) were calculated for the incidence rate, whereas pooled odds ratios (ORs) were calculated for the risk factors for which the OR was reported in three or more studies.

FINDINGS

Fourteen studies were included in the review with 5483 patients for the assessment of incidence, whereas seven of these studies with 2170 patients were included for the analysis of risk factors. In the meta-analysis, the incidence of CRKp infections after colonization was 23.2% (17.9-28.5). Additionally, three independent risk factors for subsequent CRKp infections were identified as admission to the intensive care unit (ICU) (2.59; 95% CI: 1.64-4.11), invasive procedures (2.53; 95% CI: 1.59-4.03), and multi-site colonization (6.24; 95% CI: 2.38-16.33).

CONCLUSION

This review reveals the incidence of CRKp infections in rectal carriers in different countries, emphasizing the role of rectal colonization with CRKp as an important source of nosocomial infections. Significantly, the risk factors indicated in this review can assist clinicians in identifying CRKp carriers with an elevated risk of subsequent infections, thereby enabling further measures to be taken to prevent nosocomial infections.

New advances in management and treatment of multidrug-resistant Klebsiella pneumoniae

INTRODUCTION

The management of multidrug-resistant (MDR) Klebsiella pneumoniae (KP) represents a major challenge in the field of infectious diseases. It is associated with a high rate of nosocomial infections with a mortality rate that reaches approximately 50%, even when using an effective antimicrobial therapy. Therefore, combined actions addressing infection control and antibiotic stewardship are required to delay the emergence of resistance. Since new antimicrobial agents targeting MDR-GNB bacteria have been produced during the last years and are now available for physicians to treat MDR, it is fundamental to choose appropriate antimicrobial therapy for K. pneumoniae infection.

AREAS COVERED

The PubMed database was searched to review the most significant recent literature on the topic, including data from articles coming from endemic areas and from the current European and American Guidelines.

EXPERT OPINION

We explore the most effective strategies for prevention of MDR-KP spread and the currently available treatment options, focusing on comparing old strategies and new compounds. We reviewed data concerning newly developed drugs that could play an important role in the future; we also propose a treatment algorithm that could be useful for physicians in daily clinical practice.

The Molecular Characterization of Nosocomial Carbapenem-Resistant Klebsiella pneumoniae Co-Harboring blaNDM and blaOXA-48 in Jeddah

Carbapenem-resistant Klebsiella pneumoniae (CRKP)-associated infections have become a major concern and life-threatening worldwide. Understanding the epidemiology of CRKP using a reliable molecular technology can help to develop an effective infection control policies. In the western region of Saudi Arabia, there are no sufficient data on the prevalence of CRKP and its carbapenem-resistant determinants. Therefore, this study aimed to determine the molecular epidemiology of CRKP and identify the most common carbapenemase genes. In the current study, a total of 191 CRKP isolates were collected and obtained from clinical specimens of patients at King Fahad Armed Forces Hospital (KFAFH), Jeddah, Saudi Arabia. All isolates that were resistant or intermediately susceptible to either of the carbapenem antimicrobials (imipenem, meropenem, or ertapenem) were included. All CRKP showed resistance to ceftazidime, cefepime, and piperacillin/tazobactam, whereas low (14%) and moderate (37.7%) levels of resistance were reported against tigecycline and colistin, respectively. The most common carbapenemase genes identified were blaOXA-48 (n = 157 [82.2%]), followed by blaNDM in 27 (14%) isolates. The blaVIM and blaKPC were reported in only one isolate each and no blaIMP producers were detected among all tested isolates. The high prevalence of OXA-48 among K. pneumoniae isolates reported in the current study may reflect that OXA-48 has become an endemic in Saudi Arabian hospitals. The second major finding was that the identification of CRKP co-harbors both blaNDM and blaOXA-48, and such isolates can be threating for healthcare societies (patients and healthcare workers) due to their high level of resistance to carbapenems. These results suggest that the use of molecular diagnostic methods and proper surveillance programs are required to monitor and control the spread of all multidrug-resistant (MDR) bacteria, including CRKP. Therefore, further research is recommended to expand the study and further analyze the genotyping of the most common clones of CRKP in other hospitals in the western regions of Saudi Arabia.

Epidemiology and infection control of carbapenem resistant Acinetobacter baumannii and Klebsiella pneumoniae at a German university hospital: a retrospective study of 5 years (2015-2019)

Background

Carbapenem resistant (CR) Klebsiella pneumoniae (Kp) and Acinetobacter baumannii (Ab) are emerging multidrug resistant bacteria with very limited treatment options in case of infection. Both are well-known causes of nosocomial infections and outbreaks in healthcare facilities.

Methods

A retrospective study was conducted to investigate the epidemiology of inpatients with CR Kp and CR Ab in a 1500-bed German university hospital from 2015 to 2019. We present our infection control concept including a weekly microbiologic screening for patients who shared the ward with a CR Kp or CR Ab index patient.

Results

Within 5 years, 141 CR Kp and 60 CR Ab cases were hospitalized corresponding to 118 unique patients (74 patients with CR Kp, 39 patients with CR Ab and 5 patients with both CR Ab and CR Kp). The mean incidence was 0.045 (CR Kp) and 0.019 (CR Ab) per 100 inpatient cases, respectively. Nosocomial acquisition occurred in 53 cases (37.6%) of the CR Kp group and in 12 cases (20.0%) of the CR Ab group. Clinical infection occurred in 24 cases (17.0%) of the CR Kp group and in 21 cases (35.0%) of the CR Ab group. 14 cases (9.9%) of the CR Kp group and 29 cases (48.3%) of the CR Ab group had a history of a hospital stay abroad within 12 months prior to admission to our hospital. The weekly microbiologic screening revealed 4 CR Kp cases caused by nosocomial transmission that would have been missed without repetitive screening.

Conclusions

CR Kp and CR Ab cases occurred infrequently. A history of a hospital stay abroad, particularly in the CR Ab group, warrants pre-emptive infection control measures. The weekly microbiologic screening needs further evaluation in terms of its efficiency.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06900-3.

Molecular characterization of carbapenemase producing Klebsiella pneumoniae strains by multiplex PCR and PFGE methods: The first K.pneumoniae isolates co-producing OXA-48/KPC and KPC/NDM in Turkey

INTRODUCTION

Carbapenems are frequently used in the treatment of multidrug-resistant infections caused by Klebsiella pneumoniae. The aim of the study is to definition and incidence of transferable carbapenemase genes of carbapenem resistant K. pneumoniae (CRKP) and to determine clonal relatedness of these strains in tertiary care hospital in Turkey.

METHODS

Identification of all 100 K. pneumoniae isolates and low sensitivity to any of the carbapenem group antibiotics were determined by Vitek-2 (BioMérieux, France). The frequency of carbapenemase genes (bla_OXA-48, bla_NDM, bla_KPC, bla_VIM,bla_IMP) and extended spectrum beta-lactamase (ESBL) genes (bla_CTX-M, bla_SHV, bla_TEM) which frequently detected in Turkey, have been investigated by multiplex polymerase chain reaction (PCR). Clonal relatedness was determined using Pulsed-field gel electrophoresis(PFGE).

RESULTS

Ninety five isolates carried at least one of the carbapenemase genes (81.05% bla_OXA-48, 38.9% bla_NDM, 9.47% bla_KPC,1.05% bla_VIM). One isolate was carried the bla_OXA-48+KPC and the two isolates were carried the bla_KPC+NDM. PFGE demonstrated the presence of 24 pulse types and 63.09% of the isolates were in four main pulse types.

CONCLUSIONS

This study demonstrated the incidence of bla_NDM is beginning to reach endemic levels, in addition to bla_OXA-48 found endemic in Turkey. To our knowledge, this is the first report of the co-production of these two genes (bla_{KPC + NDM} and bla_{OXA-48 + KPC}) in CRKP isolates.

Ceftazidime - Avibactam susceptibility among carbapenem-resistant Enterobacterales in a pilot study in Turkey

This study aimed to detect carbapenemase genes and to determine the in vitro susceptibility of Ceftazidime-Avibactam (CZA) in Enterobacterales isolates. Carbapenemase genes were detected by polymerase chain reaction. CZA sensitivity of isolates was evaluated with broth microdilution (BMD) and disk diffusion methods. A total of 318 carbapenem-resistant Enterobacterales isolates were included. Most of the isolates (n = 290, 91.2%) were identified as Klebsiella pneumoniae. The most common carbapenemase type was OXA-48 (n = 82, 27.6%). CZA susceptibility was evaluated in 84 isolates with OXA-48 and KPC carbapenemase activity. Both BMD and disk diffusion methods revealed that 95.2% of the isolates were sensitive to CZA; whereas, 4 (4.76%) isolates were resistant to CZA. Among colistin resistant isolates, 96.5% (n = 80) of them were susceptible to CZA. Our study demonstrated high in vitro efficacy of CZA in Enterobacterales isolates producing OXA-48 carbapenemase. High susceptibility rates against colistin resistant isolates which generally are also pan drug resistant, makes CZA a promising therapeutic choice for difficult-to-treat infections. Due to its high correlation with the BMD, disk diffusion method is a suitable and more practical method in detecting CZA in vitro activity.

Dissemination of VIM-producing Pseudomonas aeruginosa associated with high-risk clone ST654 in a tertiary and quaternary hospital in Makkah, Saudi Arabia

To the best of our knowledge, no molecular surveillance that has been conducted to identify the most common clones of carbapenem-resistant Pseudomonas aeruginosa (CRPA) in western Saudi Arabia. Therefore, this study aimed to identify genetic diversity and the most common CRPA clones in this region. Thirty-five CRPA isolates were collected from a tertiary and quaternary hospital in Makkah. bla _VIM was the most common carbapenemase-encoding gene (11 CRPA isolates), while bla_GES was reported in only three isolates. CRPA isolates were subjected to multi- locus sequence typing and showed relatively high genetic diversity with 20 sequence types. Approximately one-third (31.4%) of the CRPA isolates belonged to two high-risk clones (ST235 and ST654). This troublesome finding raises serious concerns about the emergence and further dissemination of CRPA high-risk clones in local hospitals and suggest that surveillance programs should be established in this region to monitor and control clonal dissemination of all multidrug resistant bacteria, including CRPA.

Rectal colonization with multidrug-resistant gram-negative bacteria in patients with hematological malignancies: a prospective study

OBJECTIVES

To investigate the risk factors for rectal colonization with carbapenem-resistant Enterobacteriaceae (CRE) and extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBL-E) in hematological malignant patients with febrile neutropenia (FN); rate of rectal colonization and infection/colonization with CRE and ESBL-E; whether empirical treatment can be revised.

METHODS

Adult patients receiving chemotherapy were included. Rectal swab cultures of patients were screened for CRE and ESBL-E using selective chromogenic agars.

RESULTS

Fifty-seven FN episodes of 57 patients were studied. Rectal colonization rates were 40.4% (23/57) and 8.8% (5/57) for ESBL-E and CRE, respectively. ESBL-E bacteremia was diagnosed in 2 (8.6%) ESBL-E colonized patients, while CRE bacteremia was detected in 1 (20%) CRE colonized patient. Amikacin (100%) and carbapenem (93%) were the most effective antibiotics against gram-negative enteric bacteria. Beta-lactam usage within the last 3 months was a significant risk factor for ESBL-E colonization.

CONCLUSIONS

For the treatment of FN patients either colonized with ESBL-E or having significant risk factors for ESBL-E infection, aminoglycoside containing combinations may become an alternative to carbapenems due to their high sensitivity rates. When CRE colonized hematological cancer patients develop FN or if they are hemodynamically unstable, CRE covering empiric antibiotherapy should be preferred due to high mortality rates of CRE bacteremia.

Epidemiology of carbapenemase-producing Enterobacterales in the Middle East: a systematic review

Introduction: The Middle East is actually recognized as endemic for carbapenemases-producing Enterobacterales (CPE) including at least OXA-48-like and NDM-like.Areas covered: We performed a search of PubMed and Scopus using relevant keywords. We included peer-reviewed articles published only in English reporting any data on carbapenemase-producing bacteria from Middle East countries. The last literature search was performed on 26 October 2019. All studies describing carbapenemase-producing Enterobacterales isolated from humans, animals or environmental samples from the Middle East were included.Expert opinion: The Middle-East is considered an endemic region for CPE strains and the extensive international exchange could facilitate the spread of CPE from these countries to other parts of the Globe in which the prevalence of the CPE is low. The expansion of the Middle East conflict has been associated with the rapid collapse of the existing health care system of the concerned countries. Considering that Millions of refugees have fled their country, they could introduce these CPE strains in countries with low endemicity. In conclusion, the health care system actors should take in a count the endemicity of CPE in these countries and develop local surveillance programs to limit the spread of these MDR bacteria.

Carbapenem-resistant Klebsiella pneumonia infection outbreak in a tertiary urology clinic: analysis of influencing factors with a controlled trial

Background/aim

Carbapenem-resistantKlebsiella pneumoniae (CR-KP) infections encountered in urology patients differentiate from infections caused by other factors, both in respect to prophylaxis and treatment stage, and require a special approach. We aimed to analyse the predisposing factors and the antibiotherapies for CR-KP infection outbreak in a tertiary urology clinic.

Materials and methods

There were 75 patients in the CR-KP positive group (Group I) and 146 patients in the CR-KP negative group (Group II). Analysis of the predisposing factors for CR-KP infection and comparison of the reinfection rate and the antibiotherapies in the 2 groups were the endpoints.

Results

In the first group, age, comorbidity, previous antibiotic use, and nephrostomy tube rates were higher (P = 0.015, P = 0.001, P = 0.004, and P < 0.001, respectively). In the second group, open urological surgery rate, and the proportion of patients presenting with flank pain, lower urinary tract symptoms, and haematuria were higher (P = 0.029, P < 0.001, P < 0.001, and P = 0.007). In the first group, the proportion of patients treated with transurethral bladder tumour resection was higher, whereas, percutaneous nephrolithotomy was higher in the second group (P = 0.045 for both). While hospitalization and Foley catheterization duration were longer in the first group (P < 0.001 for both), double J stent and nephrostomy duration were longer in the second group (P < 0.001 and P = 0.005). Mean leukocyte count at admission was higher in the first group (P < 0.001).

Conclusion

Advanced age, comorbidities, previous antibiotic use, and prolonged Foley catheterization duration are predisposing factors for this infection in the urology department. Two-week administration of combination antibiotic regimens containing carbapenem were effective for the treatment of this infection.

Understanding the Epidemiology of Multi-Drug Resistant Gram-Negative Bacilli in the Middle East Using a One Health Approach

In the last decade, extended-spectrum cephalosporin and carbapenem resistant Gram-negative bacilli (GNB) have been extensively reported in the literature as being disseminated in humans but also in animals and the environment. These resistant organisms often cause treatment challenges due to their wide spectrum of antibiotic resistance. With the emergence of colistin resistance in animals and its subsequent detection in humans, the situation has worsened. Several studies reported the transmission of resistant organisms from animals to humans. Studies from the middle east highlight the spread of resistant organisms in hospitals and to a lesser extent in livestock and the environment. In view of the recent socio-economical conflicts that these countries are facing in addition to the constant population mobilization; we attempt in this review to highlight the gaps of the prevalence of resistance, antibiotic consumption reports, infection control measures and other risk factors contributing in particular to the spread of resistance in these countries. In hospitals, carbapenemases producers appear to be dominant. In contrast, extended spectrum beta lactamases (ESBL) and colistin resistance are becoming a serious problem in animals. This is mainly due to the continuous use of colistin in veterinary medicine even though it is now abandoned in the human sphere. In the environment, despite the small number of reports, ESBL and carbapenemases producers were both detected. This highlights the importance of the latter as a bridge between humans and animals in the transmission chain. In this review, we note that in the majority of the Middle Eastern area, little is known about the level of antibiotic consumption especially in the community and animal farms. Furthermore, some countries are currently facing issues with immigrants, poverty and poor living conditions which has been imposed by the civil war crisis. This all greatly facilitates the dissemination of resistance in all environments. In the one health concept, this work re-emphasizes the need to have global intervention measures to avoid dissemination of antibiotic resistance in humans, animals and the environment in Middle Eastern countries.

Resurrecting Old β-Lactams: Potent Inhibitory Activity of Temocillin against Multidrug-Resistant Burkholderia Species Isolates from the United States

Burkholderia spp. are opportunistic human pathogens that infect persons with cystic fibrosis and the immunocompromised. Burkholderia spp. express class A and C β-lactamases, which are transcriptionally regulated by PenR_A through linkage to cell wall metabolism and β-lactam exposure. The potency of temocillin, a 6-methoxy-β-lactam, was tested against a panel of multidrug-resistant (MDR) Burkholderia spp. In addition, the mechanistic basis of temocillin activity was assessed and compared to that of ticarcillin. Susceptibility testing with temocillin and ticarcillin was conducted, as was biochemical analysis of the PenA1 class A β-lactamase and AmpC1 class C β-lactamase. Molecular dynamics simulations (MDS) were performed using PenA1 with temocillin and ticarcillin. The majority (86.7%) of 150 MDR Burkholderia strains were susceptible to temocillin, while only 4% of the strains were susceptible to ticarcillin. Neither temocillin nor ticarcillin induced bla expression. Ticarcillin was hydrolyzed by PenA1 (k _cat/K_m = 1.7 ± 0.2 μM^-1 s^-1), while temocillin was slow to form a favorable complex (apparent K_i [K_{i  app}] = ∼2 mM). Ticarcillin and temocillin were both potent inhibitors of AmpC1, with K_{i  app} values of 4.9 ± 1.0 μM and 4.3 ± 0.4 μM, respectively. MDS of PenA revealed that ticarcillin is in an advantageous position for acylation and deacylation. Conversely, with temocillin, active-site residues K73 and S130 are rotated and the catalytic water molecule is displaced, thereby slowing acylation and allowing the 6-methoxy of temocillin to block deacylation. Temocillin is a β-lactam with potent activity against Burkholderia spp., as it does not induce bla expression and is poorly hydrolyzed by endogenous β-lactamases.

Risk factors for rectal colonization of carbapenem-resistant Enterobacteriaceae in a tertiary care hospital: a case-control study from Turkey

Background/aim

This study aimed to evaluate the risk factors of patients colonized with carbapenem-resistant Enterobacteriaceae (CRE).

Materials and methods

The study was conducted between January 2010 and March 2016. The colonized group consisted of patients who had a CRE strain in their rectal swab cultures, whereas patients with negative rectal surveillance cultures for CRE who were concurrently hospitalized in the same units with the colonized group patients were included in the control group.

Results

The number of patients in the colonized and the control group was 71 and 120, respectively. Both groups were evaluated for demographic and healthcare-associated characteristics. Isolated microorganisms in rectal surveillance cultures for CRE were Klebsiella pneumoniae (75.5%), Escherichia coli (15.5%), Enterobacter cloacae (4.2%), Klebsiella oxytoca (1.4%), and Klebsiella terrigena (1.4%). The isolates were resistant to imipenem, meropenem, and ertapenem (52.1%, 73.2%, and 100%, respectively). In multivariate analysis, presence of decubitus, colistin usage, glycopeptide usage, and fluoroquinolone usage were found to be independent risk factors for CRE colonization. There was no significant difference between the two groups with regards to mortality (P = 0.070).

Conclusion

These results are in agreement with the current literature. The findings of this study could be useful for improvement of infection control strategies related to CRE.

Characterization of Resistance Genes and Polymerase Chain Reaction-Based Replicon Typing in Carbapenem-Resistant Klebsiella pneumoniae

Background: Fifty isolates of Klebsiella pneumoniae isolated from clinical samples between 2012 and 2016 that were found to be resistant to carbapenems were included in this study. Materials and Methods: Resistance genes were investigated by performing PCR. Plasmid typing was performed using PCR-based replicon typing. The clonal relationships between the strains were investigated using pulsed-field gel electrophoresis (PFGE). Results: OXA-48-type carbapenemase genes were detected in 86% (n = 43/50) of K. pneumoniae isolates, whereas NDM-type carbapenemase genes were detected in 14% (n = 7/50) of the isolates. bla_TEM was detected 60% (n = 30) of the strains, bla_SHV in 78% (n = 39), bla_CTX-M-1 in 48% (n = 24), and bla_CTX-M-2-type β-lactamase in 10% (n = 5). bla_CTX-M-1 and bla_SHV were concomitantly distributed in 40% (n = 20) of the strains, bla_TEM and bla_SHV in 54% (n = 27), bla_TEM, bla_SHV, and bla_CTX-M-1 in 32% (n = 16) and bla_CTX-M-1 and bla_CTX-M-2 in 10% (n = 5). Strain numbers 66, 69, 76, 77, and 78 coproduced carbapenemases, bla_CTX-M-1 and bla_CTX-M-2 in addition to bla_OXA-48 or bla_NDM-1 that were described as hybrid strains. IncR-type replicon was found in 50% (n = 25) of 50 isolates with plasmid typing, whereas IncA/C-type replicon was detected in 40% (n = 20) and IncFIIK-type replicon in 18% (n = 9) of the isolates. Outcomes of the transformation experiments showed that the OXA-48 gene was carried to the receiver cell on FII plasmids. No dominant epidemic clone was detected through PFGE. Conclusion: OXA-48 carbapenemase was found to be the most prevalent type of enzyme in our hospital, and the presence of NDM-1-type carbapenemase-carrying strain and an increase in their rate were detected.

The emergence of carbapenem-resistant Klebsiella pneumoniae isolates producing OXA-48 and NDM in the Southern (Asir) province, Saudi Arabia

OBJECTIVES

To identify the prevalence of carbapenem-resistant Klebsiella pneumoniae (CRKP) and the most common types of cabapenemases among CRKP in the Southern (Asir) province hospitals, Saudi Arabia. Methods: The cross-sectional study was conducted between late April and September in 2015. A total of 54 Klebsiella pneumoniae (K. pneumoniae) isolates with reduced sensitivity to carbapenems were obtained from various clinical specimens of the 2 largest hospitals in the Southern province. Minimum inhibitory concentrations (MICs) of carbapenems were confirmed using E-test. Molecular detection of the most common carbapenemase genes (blaIMP, bla-carbapenem-hydrolyzing oxacillinase [OXA-48], blaVIM, bla-New Delhi metallo-ß-lactamas [NDM], and blaKPC) was performed using multiplex-polymerase chain reaction. Results: The current study found that increasing age and intensive care unit admission were associated with CRKP isolation. The major type of carbapenemases was OXA-48 with 81.5% (n=44) and it seems to reach an endemic level. New Delhi metallo-ß-lactamas (NDM) was the second most frequent carbapenemase by 7.4% (n=4) of isolates while Verona integron-encoded metallo-ß-lactamase (VIM) was reported only in one isolate. Conclusion: Saudi Arabia receives large numbers of visitors and migrant workers from OXA-48 and NDM endemic countries such as Turkey, India, and Pakistan every year.

Reducing the impact of carbapenem-resistant Enterobacteriaceae on vulnerable patient groups: what can be done?

PURPOSE OF REVIEW

Carbapenem-resistant Enterobacteriaceae (CRE) is a worldwide challenge and associated with a high mortality rate in critically ill patients. This review focused on rapid diagnosis, optimization of antimicrobial therapy, and implication of effective infection control precautions to reduce impact of CRE on vulnerable patients.

RECENT FINDINGS

Several new diagnostic assays have recently been described for the early diagnosis of CRE. Retrospective studies are supportive for colistin plus meropenem combination for the treatment of CRE infections; however, solid evidence is still lacking. Ceftazidime-avibactam may be an effective therapeutic agent for infections caused by carbapenem-hydrolyzing oxacillinase-48 and Klebsiella pneumoniae carbapenamase-producing Enterobacteriaceae, but not for New Delhi metallo-β-lactamase producers. Gastrointestinal screening may permit early identification of patients with CRE infections. There is not enough evidence to recommend selective digestive decontamination for CRE carriers.

SUMMARY

The information for rapid diagnosis of CRE is accumulating. There are new agents with high in-vitro activity against CRE, but clinical experience is limited to case reports. Active surveillance with a high rate of compliance to basic infection control precautions seems to be the best approach to reduce the impact of CRE on vulnerable patients.

Findings from an outbreak of carbapenem-resistant Klebsiella pneumoniae emphasize the role of antibiotic treatment for cross transmission

PURPOSE

In January 2015, we noticed by rectal swab analyses that seven of 23 patients at an early rehabilitation ward had been colonized with carbapenem-resistant Klebsiella pneumoniae (CKP). Here, we describe risk factors for CKP acquisition.

METHODS

In the present study, the outbreak is described and risk factors for CKP acquisition are examined, e.g., antibiotic treatment. Microbiological analyses including corresponding results were examined to study when colonization with CKP occurred and whether patients had suffered from diarrhea. To examine whether spread of bacteria was clonal, multi-locus sequence typing as well as Xbal macrorestriction and pulsed-field gel electrophoresis was performed. The presence of carbapenmase was examined by PCR analysis. Through univariate analysis of risk factors in the small study sample, the role of antibiotic consumption, isolation procedures, patient's age, gender, and Barthel index on colonization was elucidated.

RESULTS

Clonal spread of the novel sequence type (ST)2255 was identified. Additionally, one patient was colonized with Escherichia coli and Serratia marcescens, both resistant to carbapenems, while a further patient carried another carbapenem-resistant E. coli strain. In all isolates, carbapenemase gene bla _OXA-48 was found to be located on a conjugative plasmid (60 kb), suggesting in vivo transmission from CKP to E. coli and S. marcescens. Univariate tests indicated that antibiotic treatment was the only risk factor showing a significant association with being colonized by CKP. In addition, the likelihood of diarrhea appeared to be higher in this group. Antibiotic treatment was associated with CKP colonization, whereas patients´ age, gender, Barthel index at admission, and residence with a CKP-colonized roommate were not. Diarrhea also seemed to support to distribution of CKP.

CONCLUSIONS

In this small outbreak, antibiotic treatment seemed to be the predominant risk factor for monoclonal transmission of bla _OXA-48 positive CKP.