Genomic Investigation of Carbapenem-Resistant Klebsiella pneumonia Colonization in an Intensive Care Unit in South Africa

Genomic analysis of virulent, multidrug resistant Klebsiella pneumoniae and Klebsiella oxytoca from bloodstream infections, South Africa

The study investigated the resistome, virulome and mobilome of multidrug resistant (MDR) Klebsiella pneumoniae and Klebsiella oxytoca clinical isolates.

METHODS

A total of 46 suspected Klebsiella species (spp.) were collected from blood cultures within the uMgungundlovu District in the KwaZulu-Natal Province. Antibiotic susceptibility was determined against a panel of 19 antibiotics using the disk diffusion test. A subset of 14 MDR K. pneumoniae (n = 10) and K. oxytoca (n = 4) isolates were selected based on their antibiograms and subjected to whole genome sequencing (WGS). The sequence types (STs), resistome, virulome, mobilome, capsule loci (KLs) were analysed using relevant WGS and bioinformatics tools.

RESULTS

Of the 10 K. pneumoniae sequence types (ST) identified, the most common were ST25 (n = 3), ST101 (n = 3), and 4 K. oxytoca belonged to ST450 (n = 3). The two high-risk K. pneumoniae clones ST15, and ST17 were identified. O and K capsule types were identified, with predominance of KL2, KL17, KL29, O1/O2v2, O1/O2v1, and OL104 respectively. The majority of isolates displayed multidrug resistance predominantly carrying β-lactamase genes, including blaCTX-M-15, blaTEM-1B, blaSHV, and blaOXA-1, and blaOXY including the carbapenemase blaOXA-181 in two (14.3 %) study isolates. Other resistance genes included: aac(6')-lb-cr, aac(3), aac, aph, aad, dfr, tet(A), and tet(D), mph(A), sul1, sul2, oqx, qnr, acrR, ramR, parC, gyrA, arr-3, cat, fosA, qacE genes conferring resistance to aminoglycosides, trimethoprim, tetracycline, macrolide, sulfonamides, fluoroquinolones, rifampicin phenicols, fosfomycin, and quaternary ammonium compound disinfectant. Virulence factors related to hypervirulence: encoding aerobactin (iuc, iutA), salmochelin (iro), yersiniabactin (ybt), enterobactin (ent), type 1 and 3 (mrk and fim), and capsule synthesis (rcsA and rcsB) were identified. IncF, IncR, and Col plasmid replicon types and class I integrons were detected, with IncFIB(K) predominance. The blaCTX-M-15 and blaTEM-1 genes were bracketed by Tn3 transposons, ISEc9, recombinase and IS91 insertion sequences.

CONCLUSIONS

The convergence of multidrug resistance and hypervirulence genes in Klebsiella strains is a potential clinical concern. Carbapenemase, ESBL screening and genomic surveillance are urgently required in hospital environments.

Carbapenem resistance in Enterobacterales: Predicting clinical outcomes in bloodstream infections

PURPOSE

Carbapenem-resistant Enterobacterales (CRE) are a global concern due to their high mortality rates and limited therapeutics. CRE-caused bloodstream infections (BSIs) are challenging to manage, especially in healthcare settings. This study aimed to investigate the predictors of mortality in BSI patients caused by CRE.

METHODS

A single center prospective study to examine the characteristics of BSI caused by CRE in a large academic hospital over 15 months. The main outcomes were microbiological characteristics and clinical outcomes of patients at 28 days based on a step-wise regression analysis.

RESULTS

A total of 76 episodes of BSI due to CRE were included. The study found that the most common type of carbapenemase was OXA-48 (69.7 %, n = 53), followed by the co-existence of OXA-48 and MBL (26.3 %, n = 20), with Klebsiella pneumoniae being the most common (90 %, n = 69). Patients with OXA-48-BSI were more likely to have a urinary source of infection, while patients with MBL-BSI were more likely to have a non-urinary source of infection. All cases (100 %) had medical devices. Around 30.3 % of patients received effective empirical treatment, while 61.8 % received adequate therapy at 48 h. The overall mortality rate was 42.1 % (n = 32), and the main predictors of mortality in this study were the presence of sepsis and inadequate initial therapy, while age >65 predicted mortality in the linear regression but not the stepwise regression model.

CONCLUSION

CRE-BSIs are a serious health threat. The study highlights the need for preventive strategies focused on high-risk patients and proper device management to reduce BSI.

The Importance of Carbapenemase-Producing Enterobacterales in African Countries: Evolution and Current Burden

Antimicrobial resistance (AMR) is a worldwide healthcare problem. Multidrug-resistant organisms (MDROs) can spread quickly owing to their resistance mechanisms. Although colonized individuals are crucial for MDRO dissemination, colonizing microbes can lead to symptomatic infections in carriers. Carbapenemase-producing Enterobacterales (CPE) are among the most important MDROs involved in colonizations and infections with severe outcomes. This review aimed to track down the first reports of CPE in Africa, describe their dissemination throughout African countries and summarize the current status of CRE and CPE data, highlighting current knowledge and limitations of reported data. Two database queries were undertaken using Medical Subject Headings (MeSH), employing relevant keywords to identify articles that had as their topics beta-lactamases, carbapenemases and carbapenem resistance pertaining to Africa or African regions and countries. The first information on CPE could be traced back to the mid-2000s, but data for many African countries were established after 2015-2018. Information is presented chronologically for each country. Although no clear conclusions could be drawn for some countries, it was observed that CPE infections and colonizations are present in most African countries and that carbapenem-resistance levels are rising. The most common CPE involved are Klebsiella pneumoniae and Escherichia coli, and the most prevalent carbapenemases are NDM-type and OXA-48-type enzymes. Prophylactic measures, such as screening, are required to combat this phenomenon.

Molecular Screening of Carbapenem-Resistant K. pneumoniae (CRKP) Clinical Isolates for Concomitant Occurrence of Beta-Lactam Genes (CTX-M, TEM, and SHV) in the Kingdom of Bahrain

The emergence of extended-spectrum β-lactamase-producing Klebsiella pneumoniae, including CRKP infections, has resulted in significant morbidity and mortality worldwide. We aimed to explore the presence of bla genes (CTX-M, TEM, and SHV) in CRKP isolates. A total of 24 CRKP isolates were randomly selected from the Salmaniya Medical Complex Microbiology Laboratory. These isolates, which were positive for carbapenemases, were further explored for CTX-M, TEM, and SHV genes using PCR. All the CTX-M PCR amplicons were sent for sequencing. To determine genetic relatedness, molecular typing by ERIC-PCR was performed. The bla gene testing demonstrated that a significant proportion of these isolates harbored SHV, CTX-M, and TEM genes (100%, 91.6%, and 45.8%), respectively. Bioinformatic analyses confirmed CTX-M-15 in these isolates. ERIC-PCR analysis showed three clusters demonstrating genetic relatedness. The study findings reveal the concomitant carriage of the SHV and CTX-M-15 and a comparatively lower carriage of TEM genes in CRKP isolates. Our findings highlight the significance of routinely reporting the presence of antibiotic resistance genes along with regular antibiotic sensitivity reports, as this will aid clinicians in prescribing appropriate antibiotics.

Evaluation of intermittent antimicrobial infusion documentation practices in intensive care units: A cross-sectional study

OBJECTIVE

To observe nurse administration of carbapenem antibiotics, in the context of medication safety measures, in intensive care units.

RESEARCH METHODOLOGY/DESIGN

A quantitative study was conducted using observation principles.

SETTING

Three adult private and public Intensive Care Units in the health district of a capital city in KwaZulu-Natal, South Africa.

MAIN OUTCOME MEASURES

Nurse practices were observed for double-checking of the medication order, medication vial, and method of preparation and administration. Infusion bags were inspected for nurse labelling of medication and patient details. Patient medication treatment charts were inspected for nurse signature.

RESULTS

Carbapenem infusion administrations (n = 223) to twenty patients were observed. Adherence to the scheduled time occurred in 34.9% administrations, 5.4% doses were not given, and an incorrect dose given on 1.4% administrations. One hundred and forty-four (64.6%) infusion bags were inspected during the administrations: there was no medication label affixed to 21.5% bags, and only 8.3% of bags were labelled with essential details; the patient's name, drug, dose, date, time, signature of the nurse mixing and administering the dose, and signature of the secondary nurse.

CONCLUSION

There was a lack of compliance with accepted medication risk mitigation measures. Sub-optimal double-checking resulted in the incorrect dose given, missed dose, and non-adherence to scheduled administration time. This has implications for the optimal administration of antimicrobial medications, raising concerns about the efficacy of treatment for critically ill patients.

IMPLICATIONS FOR CLINICAL PRACTICE

Parenteral administration errors pose a challenge in acute care areas. Risk mitigation measures include double-checking of medications. If antimicrobial treatment is not administered at the prescribed dosing intervals, this may have implications for the efficacy of time-dependent broad-spectrum antibiotics such as carbapenems. Medication administration errors involving antimicrobial medications should therefore be considered as high-risk errors, with the potential to contribute towards antimicrobial resistance.

Epidemiology, risk factors, and clinical outcomes of carbapenem-resistant Enterobacterales in Africa: A systematic review

OBJECTIVES

Carbapenem-resistant Enterobacterales (CRE) commonly cause hospital-acquired infections and hospital outbreaks worldwide, with an alarming increase in Africa, necessitating review of regional CRE epidemiological trends.

METHODS

A systematic review was conducted using PRISMA guidelines, searching PubMed, Scopus and Web of Science databases for studies describing CRE distribution, risk factors for CRE acquisition and clinical outcome of CRE infections in Africa.

RESULTS

One-hundred and sixty-nine studies were included, with the majority from North Africa (92/169, 54.4%). Most studies (136/169; 80.4%) focused only on infection, with a total of 15666 CRE isolates (97.4% clinical infection, 2.6% colonisation). The leading bacterial species included Klebsiella (72.2%), Escherichia coli (13.5%), and Enterobacter (8.3%). The most frequently detected carbapenemases were NDM (43.1%) and OXA-48-like (42.9%). Sequence types were reported in 44 studies, with ST101 and ST147 most commonly reported in K. pneumoniae, and ST410, ST167 and ST38 in E. coli. Previous antibiotic use, prior hospitalisation, surgical procedures, indwelling devices, intensive care unit admission and prolonged hospital stay, were the most frequent factors associated with CRE infection/colonisation. Crude mortality for CRE infection was 37%.

CONCLUSION

Although K. pneumoniae and E. coli remain the most frequent CRE in Africa, observed sequence types are not the commonly reported global 'high-risk' clones. The distribution of species and carbapenemases differs across African regions, while risk factors for CRE colonisation/infection, and patient outcomes are similar to those reported globally. There are limited data on CREs from parts of Africa, highlighting the need to strengthen epidemiologic surveillance programmes in the region.

Outbreak of NDM-1- and OXA-181-Producing Klebsiella pneumoniae Bloodstream Infections in a Neonatal Unit, South Africa

After an increase in carbapenem-resistant Klebsiella pneumoniae (CRKP) bloodstream infections and associated deaths in the neonatal unit of a South Africa hospital, we conducted an outbreak investigation during October 2019-February 2020 and cross-sectional follow-up during March 2020-May 2021. We used genomic and epidemiologic data to reconstruct transmission networks of outbreak-related clones. We documented 31 cases of culture-confirmed CRKP infection and 14 deaths. Two outbreak-related clones (blaNDM-1 sequence type [ST] 152 [n = 16] and blaOXA-181 ST307 [n = 6]) cocirculated. The major clone blaNDM-1 ST152 accounted for 9/14 (64%) deaths. Transmission network analysis identified possible index cases of blaOXA-181 ST307 in October 2019 and blaNDM-1 ST152 in November 2019. During the follow-up period, 11 new cases of CRKP infection were diagnosed; we did not perform genomic analysis. Sustained infection prevention and control measures, adequate staffing, adhering to bed occupancy limits, and antimicrobial stewardship are key interventions to control such outbreaks.

Prevalence and incidence of carbapenem-resistant K. pneumoniae colonization: systematic review and meta-analysis

BACKGROUND

Klebsiella pneumoniae is a gram-negative rod belonging to the order Enterobacterales and having a wide distribution in the environment, including the human colon. Recently, the bacterium is one of the known problems in the healthcare setting as it has become resistant to last-resort drugs like carbapenems. The colonized person can serve as a reservoir for his/herself and others, especially in the healthcare setting leading to nosocomial and opportunistic infections. Therefore, we aimed to quantitatively estimate the rate of prevalence and incidence of colonization with carbapenem-resistant K. pneumoniae.

METHODS

A literature search was conducted on PubMed/MEDLINE, Google Scholar, Science Direct, Cochrane Library, WHO Index Medicus, and university databases. The study includes all published and unpublished papers that addressed the prevalence or incidence of K. pneumoniae colonization. Data were extracted onto format in Microsoft Excel and pooled estimates with a 95% confidence interval calculated using Der-Simonian-Laird random-effects model. With the use of I² statistics and prediction intervals, the level of heterogeneity was displayed. Egger's tests and funnel plots of standard error were used to demonstrate the publication bias.

RESULTS

A total of 35 studies were included in the review and 32 records with 37,661 patients for assessment of prevalence, while ten studies with 3643 patients for incidence of colonization. The prevalence of carbapenem-resistant K. pneumoniae colonization varies by location and ranges from 0.13 to 22%, with a pooled prevalence of 5.43%. (3.73-7.42). Whereas the incidence of colonization ranges from 2 to 73% with a pooled incidence of 22.3% (CI 12.74-31.87), both prevalence and incidence reports are majorly from developed countries. There was a variation in the distribution of carbapenem resistance genes among colonizing isolates with KPC as a prominent gene reported from many studies and NDM being reported mainly by studies from Asian countries. A univariate meta-regression analysis indicated continent, patient type, study design, and admission ward do not affect the heterogeneity (p value>0.05).

CONCLUSION

The review revealed that colonization with K. pneumoniae is higher in a healthcare setting with variable distribution in different localities, and resistance genes for carbapenem drugs also have unstable distribution in different geographic areas.

Molecular Screening of Clinical Multidrug-Resistant Gram-Negative Bacteria Shows Endemicity of Carbapenemases, Coexistence of Multiple Carbapenemases, and Rarity of mcr in South Africa

Background: Extensive use of carbapenems to treat multidrug-resistant (MDR) Gram-negative bacteria (GNB) facilitates the wide dissemination of carbapenemase-producing carbapenem-resistant GNB. Colistin was reintroduced into clinical settings to manage these GNB infections. However, there is currently an increase in the dissemination of mobile colistin resistance (mcr)-producing colistin-resistant GNB isolates in clinical settings. The epidemiology of carbapenemases and mcr in Pretoria was evaluated. Methods: Clinical MDR GNB were collected and screened for carbapenemases and mcr using polymerase chain reaction (PCR); their antibiotic susceptibility profiles were elucidated using the Vitek^® 2 automated system (Biomerieux, France) and microbroth dilution (for colistin). Results and Discussion: A total of 306 isolates were collected; a majority of these were Klebsiella pneumoniae (n = 208) and were collected from males (n = 158). The isolates were retrieved from a variety of infection sites, including urine, blood cultures, and rectal swabs. The Vitek 2 system found that these isolates were largely resistant to β-lactams, where 217 (70.9%) had reduced susceptibility to at least one carbapenem (ertapenem, meropenem, or imipenem), and 81 isolates (26.5%) were resistant to colistin. PCR screening identified 201 (65.7%) isolates harboring carbapenemase genes consisting of bla_OXA-48 (170, 84.2%), bla_NDM (31, 15.4%), bla_IMP (5, 2%), bla_KPC (4, 1%), and bla_VIM (5, 2%). Furthermore, 14 bla_OXA-48-producing isolates were coharboring bla_VIM (2), bla_NDM (9), bla_KPC (1), and bla_IMP (2) genes. Only one isolate harbored the mobile colistin resistance (mcr)-1 gene, and this is the first report of an mcr-1-producing Acinetobacter baumannii isolate in South Africa. Conclusion: There is high endemicity of carbapenemase genes and a low prevalence of mcr genes in GNB, particularly in K. pneumoniae, in health care facilities in Pretoria and surrounding regions of South Africa. Significance: Health care facilities in Pretoria are becoming breeding grounds for MDR infections that threaten public health. Careful use of carbapenems and other antibiotics is necessary to prevent further escalation and outbreak of these MDR strains that can claim several lives.

Co-Occurrence of β-Lactam and Aminoglycoside Resistance Determinants among Clinical and Environmental Isolates of Klebsiella pneumoniae and Escherichia coli: A Genomic Approach

The presence of antimicrobial-resistance genes (ARGs) in mobile genetic elements (MGEs) facilitates the rapid development and dissemination of multidrug-resistant bacteria, which represents a serious problem for human health. This is a One Health study which aims to investigate the co-occurrence of antimicrobial resistance determinants among clinical and environmental isolates of K. pneumoniae and E. coli. Various bioinformatics tools were used to elucidate the bacterial strains' ID, resistome, virulome, MGEs, and phylogeny for 42 isolates obtained from hospitalized patients (n = 20) and environmental sites (including fresh vegetables, fruits, and drinking water) (n = 22). The multilocus sequence typing (MLST) showed that K. pneumoniae belonged to ten sequence types (STs) while the E. coli belonged to seventeen STs. Multidrug-resistant isolates harbored β-lactam, aminoglycoside resistance determinants, and MGE were detected circulating in the environment (drinking water, fresh vegetables, and fruits) and in patients hospitalized with postoperative infections, neonatal sepsis, and urinary tract infection. Four K. pneumoniae environmental isolates (7E, 16EE, 1KE, and 19KE) were multidrug-resistant and were positive for different beta-lactam and aminoglycoside resistance determinants. blaCTX-M-15 in brackets of ISEc 9 and Tn 3 transposases was detected in isolates circulating in the pediatrics unit of Soba hospital and the environment. This study documented the presence of bacterial isolates harboring a similar pattern of antimicrobial resistance determinants circulating in hospitals and environments. A rapid response is needed from stakeholders to initiate a program for infection prevention and control measures to detect such clones disseminated in the communities and hospitals.

Plethora of Resistance Genes in Carbapenem-Resistant Gram-Negative Bacteria in Greece: No End to a Continuous Genetic Evolution

Carbapenem-resistant Gram-negative bacteria are a public health threat that requires urgent action. The fact that these pathogens commonly also harbor resistance mechanisms for several other antimicrobial classes further reduces patient treatment options. The present study aimed to provide information regarding the multidrug resistance genetic background of carbapenem-resistant Gram-negative bacteria in Central Greece. Strains from a tertiary care hospital, collected during routine practice, were characterized using a DNA microarray-based assay. Various different resistance determinants for carbapenems, other beta-lactams, aminoglycosides, quinolones, trimethoprim, sulfonamides and macrolides were detected among isolates of the same sequence type. Eighteen different multidrug resistance genomic profiles were identified among the twenty-four K. pneumoniae ST258, seven different profiles among the eight K. pneumoniae ST11, four profiles among the six A. baumannii ST409 and two among the three K. oxytoca. This report describes the multidrug resistance genomic background of carbapenem-resistant Gram-negative bacteria from a tertiary care hospital in Central Greece, providing evidence of their continuous genetic evolution.

Whole-Genome Sequencing (WGS) of Carbapenem-Resistant K. pneumoniae Isolated in Long-Term Care Facilities in the Northern Italian Region

K. pneumoniae (KPN) is one of the widest spread bacteria in which combined resistance to several antimicrobial groups is frequent. The most common β-lactamases found in K. pneumoniae are class A carbapenemases, both chromosomal-encoded (i.e., NMCA, IMI-1) and plasmid-encoded (i.e., GES-enzymes, IMI-2), VIM, IMP, NDM, OXA-48, and extended-spectrum β-lactamases (ESBLs) such as CTX-M enzymes. In the present study, a total of 68 carbapenem-resistant KPN were collected from twelve long-term care facilities (LTCFs) in the Northern Italian region. The whole-genome sequencing (WGS) of each KPN strain was determined using a MiSeq Illumina sequencing platform and analysed by a bacterial analysis pipeline (BAP) tool. The WGS analysis showed the prevalence of ST307, ST512, and ST37 as major lineages diffused among the twelve LTCFs. The other lineages found were: ST11, ST16, ST35, ST253, ST273, ST321, ST416, ST1519, ST2623, and ST3227. The bla_KPC-2, bla_KPC-3, bla_KPC-9, bla_SHV-11, bla_SHV-28, bla_CTX-M-15, bla_OXA-1, bla_OXA-9, bla_OXA-23, qnrS1, qnrB19, qnrB66, aac(6′)-Ib-cr, and fosA were the resistance genes widespread in most LTCFs. In this study, we demonstrated the spreading of thirteen KPN lineages among the LTCFs. Additionally, KPC carbapenemases are the most widespread β-lactamase.