Prevalence of Carbapenem-Resistant Klebsiella Pneumoniae （CRKP） and the Distribution of Class 1 Integron in Their Strains Isolated from a Hospital in Central China

我们的学习的目的是调查 Carbapenem 抵抗的 Klebsiella pneumoniae (CRKP ) 和班的基因特征的流行的目的在临床的 Klebsiella pneumoniae 拉紧的多药 resistance.Methods 上的 CRKP 的 1 integron 在华中从一所医院的多重部门被收集。CRKP 紧张在 isolates 之中被识别，并且 CRKP 紧张的抗菌素危险性被分析。聚合酶链反应(PCR ) 被采用放大类 1 个 integron 变量区域。integron 基因结构与酶消化和 DNA 定序技术被分析。在班 1 integron 和药抵抗之间的关系被分析完全， 955 Klebsiella pneumoniae 拉紧的 statistically.Results 从医院的改变的地点被孤立，并且(12.3%) 117 作为 CRKP 他们被识别，与在 2013 的8.9%的分离率( 26/292 )，11.3%( 38/336 )在 2014 和16.2%( 53/327 )在 2015 ，哪个表演到年的一个增加的趋势。(52/117 )44.4% 与 ICU 的标本 CRKP 紧张被分开，并且(72/117 )61.5% 从唾沫。超过 95% CRKP 紧张对 ampicillin/sulbactam， aztreonam， imipenem， meropenem， ceftazidme， cefotaxime， cefepime，和 piperacillin 抵抗，当相对低的抵抗的率在 tigecycline (12.8%) 和 colistin (35.9%) 被发现时。班 1 integron 在 77.8% 被检测(91/117 ) CRKP 紧张。CRKP 的班 1 integron 显著地与抗菌素抵抗被相关到 tobramycin， gentamicin 和 amikacin (所有 P < 0.01 ) 。班 1 integron 的可变区域的基因盒子分析证明 aadA2 占 64.8%(59/91 ) ， aacA4-catB8-aadA1 23.1%(21/91 ) ，并且 aadA2-dfrA25 12.1%(11/91 ).Conclusions CRKP 在他们的中国，和大多数在临床的设置有一个增加的趋势对多重抗菌素抵抗。在 CRKP 的班 1 integron 有强壮的能力从环境捕获对 aminoglycosides 抗菌素抵抗的基因，与象最流行的 aadA2 基因。

A Case of Carbapenem Resistant Non-K1/K2 Serotype <i>Klebsiella pneumoniae</i>Liver Abscess

Klebsiella pneumoniae liver abscess (KPLA) has been described as an invasive syndrome with extrahepatic complications. The majority of KPLA is caused by capsular serotype K1 and K2 isolates. We report a case of carbapenem resistant Klebsiella pneumoniae liver abscess. The patient initially presented with infected right above-the-knee amputation and was later found with a large liver abscess. Initial antimicrobial susceptibility showed carbapenem resistant K. pneumoniae (CRKP). Further molecular workup revealed that the isolate was a less virulent non-K1/K2 serotype, and both rmpA and kfu genes were negative. The lack of outer membrane porins likely contributed to the carbapenem resistance. To our knowledge, this is a first reported case of carbapenem resistant, non-K1/K2 serotype K. pneumoniae liver abscess in the United States.

Study of OmpK35 and OmpK36 Expression in Carbapenem Resistant ESBL Producing Clinical Isolates of Klebsiella pneumoniae

Background: Carbapenem resistant extended spectrum β-lactamase (ESBL) producing Klebsiella pneumoniae (K. pneumoniae) is increasing worldwide. Carbapenem resistance (CR) has been attributed not only to production of carbapenemases but also to permeability barriers due to outer membrane proteins (OmpK35 and OmpK36) disruption. Objective: Phenotypic detection of CR among ESBL producing K. pneumoniae isolates, followed by the evaluation of the role of ompK35 and ompK36 gene expression among carbapenem resistant K. pneumoniae (CR-KP) isolates. Methods: 100 ESBL producing K. pneumoniae isolates were included in this study. Minimum inhibitory concentration (MIC) of imipenem was performed for all isolates by broth microdilution method. For CR-KP isolates, phenotypic detection of K. pneumoniae carbapenemase (KPC), metallo-β-lactamase (MBL) and AmpC enzymes was performed followed by Realtime qRT-PCR to detect and quantify ompK35 and ompK36 gene expression. Results: 42% of our isolates were carbapenem resistant, and all of them were KPC producers either singly or in combination with MBL and/or AmpC production. Reduced expression of both ompK35 and ompK36 was detected in (52.38%) of CR-KP isolates, while reduced expression of ompK36 or ompK35 alone was found in (2.38%) and (33.33%) respectively. Twenty of 42 CR-KP isolates (47.62%), showing reduced ompK35 and ompK36 expression, exhibited high level resistance (HLR) (>32 μg/ml) to imipenem. There was a significant correlation between reduced expression of ompK36 and increase MIC values (p < 0.05). The combined production of MBL or AmpC together with reduced expression of ompK35 and/or ompK36 resulted in significant increase in imipenem MIC (p < 0.05). Conclusion: The combined OmpK35/OmpK36 loss resulted in HLR. However OmpK36 seems to play a major role in those strains. Imipenem MIC was markedly increased among K. pneumoniae showing carbapenemase and/or AmpC production together with loss of OmpK35 and/or OmpK36.

Predominance of Multi-Drug Resistant <i>Klebsiella pneumonia</i>and Other Gram Negative Bacteria in Neonatal Sepsis in Equatorial Guinea

The study was conducted on new-born babies in whom septicemia was suspected, to determine the prevalence of bacterial strains isolated and their sensitivity to antimicrobial drugs. The study was carried out at La Paz Medical Center, Microbiology section, Malabo, Equatorial Guinea from August 2013 to October 2015. Out of 293 septicemia suspected cases, 29 (10%) blood cultures were positive, 28 with bacterial growth and 1 with growth of Candida sp. The mortality rate of neonates caused by Gram negative bacterial sepsis was 34.7%. Among the Gram negative bacteria (24 isolates), the most common types were Klebsiella pneumoniae (16 = 69.6%), followed by Escherichia coli (4 = 17.4%) and Acinetobacter species (4 = 17.4%). Four Gram positive bacteria were also isolated and identified all ascoagulase-negative staphylococci. All the Klebsiella pneumoniae isolates and Acinetobacter species demonstrated Multi Drug Resistance against different antibiotics with Extended-spectrum β-lactamase (ESBL) activity. The most frequent causative agent of bacterial sepsis in new-born children was Klebsiella pneumoniae. An alarming level of Multi Drug Resistance (MDR) Klebsiella pneumoniae strains to the first choice antibiotic treatment was observed.

A Prospective Study on the Efficiency of Ciprofloxacin in Combination with Chloramphenicol against Multiple Antibiotics Resistant <i>Klebsiella pneumonia</i>

Pneumonia is the single largest infectious cause of death in children worldwide and also a form of an acute respiratory infection that affects the lung. The purpose of the study was to develop a new approach to treat antibiotic-resistant K. pneumoniae infection. This study aimed in quest of a drug to combine with ciprofloxacin, a broad spectrum antibiotic frequently used to treat lung infections. Methodology: A total of 23 lung infection bacterial samples were collected and studied against 14 antibiotics of different classes. The disk diffusion method was performed to determine synergy screening, MIC value, and qualitative toxicity analysis of ciprofloxacin and chloramphenicol combination. Results: After primary screening of antibiotic susceptibility, they were categorized into multidrug-resistant (MDR), extensively drug-resistant (XDR) and pan drug-resistant (PDR) pathogens where 9 isolates were MDR, 5 were XDR and 3 isolates were PDR. Furthermore, they were trialed in combination ciprofloxacin along with other 7 drugs in disk diffusion to explore the synergistic effect. The combination of ciprofloxacin and moxifloxacin, ciprofloxacin and chloramphenicol were found to be synergic. Then the MIC test was done for the combination ciprofloxacin and chloramphenicol. When the MIC result was generated, the MIC of the respective combination was analyzed. Furthermore, the fractional inhibitory concentration (FIC) was calculated and in accordance with the results of the FIC index, ciprofloxacin-chloramphenicol combination has shown value 0.4510 which revealed a synergistic effect against multi-drug resistant Klebsiella pneumoniae. Conclusion: Given these points, if the efficiency of this antibiotic can be accelerated from combination with other drugs, it might be lifesaving and cost effective as well.

A Five-year Surveillance of Carbapenemase-producing Klebsiella pneumoniae in a Pediatric Hospital in China Reveals Increased Predominance of NDM-1

Objective To characterize carbapenem （CPM）-non-susceptible Klebsiella pneumoniae （K. pneumoniae） and carbape-nemase produced by these strains isolated from Beijing Children＇s Hospital based on a five-year surveillance. Methods The Minimal Inhibition Concentration values for 15 antibiotics were assessed using the Phonixl00 compact system. PCR amplification and DNA sequencing were used to detect genes encoding carbapenemases. WHONET 5.6 was finally used for resistance analysis. Results In total, 179 strains of CPM-non-susceptible K. pneumoniae were isolated from January, 2010 to December, 2014. The rates of non-susceptible to imipenem and meropenem were 95.0% and 95.6%, respectively. In the 179 strains, 95 （53.1%） strains carried the blalMP gene, and IMP-4 and IMP-8 were detected in 92 （96.8%） and 3 （3.2%） IMP-producing isolates, respectively. 65 （36.3%） strains carried the blaNDM_1 gene. 6 （3.4%） strains carried the blaKpc gene, and KPC-2 were detected in 6 KPC-producing isolates. In addition, New Delhi-Metallo-1 （NDM-1） producing isolates increased from 7.1% to 63.0% in five years and IMP-4 producing isolates decreased from 75.0% to 28.3%. Conclusion High frequencies of multiple resistances to antibiotics were observed in the CPM-non-susceptible K. pneumoniae strains isolated from Beijing Children＇s Hospital. The production of IMP-4 and NDM-1 metallo-13-1actamases appears to be an important mechanism for CPM-non- susceptible in K. pneumoniae.

Antimicrobial Resistance Patterns and Molecular Characterization of <i>Klebsiella pneumoniae</i>in Clinical Isolates at Mbarara Regional Referral Hospital

Background: Klebsiella pneumoniae is one of the most frequent opportunistic pathogens causing a range of infections and being resistant for beta-lactamases (ESBL) and Carbapenemases. Aim: The aim of the present study was to determine the antimicrobial resistance patterns and molecular characterization establishing the phenotypes and genotypes associated with drug resistance, an antibiogram of genotypically positive isolates for resistance of Klebsiella pneumoniae in clinical isolates at MRRH. Materials and Methods: A laboratory-based descriptive cross-sectional study that was conducted from September 2018 to May 2019 at MRRH. Klebsiella pneumoniae was identified by cultural and biochemical methods. Antibiotic sensitivity test was performed by modified Kirby-Bauer disc diffusion technique. ESBL production in Klebsiella pneumoniae was tested by double-disc synergy test, Carbapenemase production by MHT, Boronic Acid or EDTA test using Meropenem phenotypically and both resistance confirmed genotypically by Multiplex PCR. Results: Out of 1055 clinical isolates, 298 (28.2%) were found positive for Klebsiella.spp, 175 isolates were subcultured among which 22 (12.57%) were K. pneumoniae based on API 20E. Overall Sensitivity patterns of these Klebsiella pneumoniae isolates to Ceftriaxone, (Amoxicillin/Clavulanate), Gentamicin, Cefepime, Ciprofloxacin, Cefoxitin, Nitrofurantoin, Cefuroxime, piperacillin/tazobactam, Meropenem, Ceftazidime and cefotaxime were 72.7%, 63.7%, 54.5%, 45.5%, 31.8%, 31.8%, 27.3%, 27.3%, 22.7%, 22.7%, 18.2%, 9.1%, 9.1% respectively. ESBL producing K. pneumoniae was found at 68.18% (15/22) phenotypically. Genotypically;the ESBL genes were blaCTX-M (100%), blaSHV (80%) and blaTEM (100;47%);8/15 (73.3%) had CTX-M, SHV, TEM, 4/15 (26.67%) CTX-M, TEM, 3/15 (20.00%) CTX-M and SHV. Carbapenemase producing K. pneumoniae was found at 31.82% (7/22) phenotypically;1/7 (14.28%) by MHT, 4/7 (57.14%) Boronic acid test and 2/7 (28.58%) EDTA test. Genotypically;3/4 [(75%) 42.86%] had OXA-48, 1/4 [(25%) 14.28%] OXA-48 and KPC gene, 1/2 [(50%) 14.28%] KPC and VIM, 1/2 [(50%) 14.28%] KPC and KPC gene [(100%) 14.28%]. Conclusion/Recommendations: DDS to be used for ESBL production, MHT, Boronic Acid test and EDTA tests using Meropenem/or Imipenem for Carbapenemase-production routinely.

Newly Detected Transmission of bla_(KPC-2) by Outer Membrane Vesicles in Klebsiella Pneumoniae

Objective The prevalence of carbapenem-resistant Klebsiella pneumoniae(CR-KP)is a global public health problem.It is mainly caused by the plasmid-carried carbapenemase gene.Outer membrane vesicles(OMVs)contain toxins and other factors involved in various biological processes,includingβ-lactamase and antibiotic-resistance genes.This study aimed to reveal the transmission mechanism of OMV-mediated drug resistance of Klebsiella(K.)pneumoniae.Methods We selected CR-KP producing K.pneumoniae carbapenemase-2(KPC-2)to study whether they can transfer resistance genes through OMVs.The OMVs of CR-KP were obtained by ultracentrifugation,and incubated with carbapenem-sensitive K.pneumoniae for 4 h.Finally,the carbapenem-sensitive K.pneumoniae was tested for the presence of bla_(KPC-2)resistance gene and its sensitivity to carbapenem antibiotics.Results The existence of OMVs was observed by the electron microscopy.The extracted OMVs had bla_(KPC-2)resistance gene.After incubation with OMVs,bla_(KPC-2)resistance gene was detected in sensitive K.pneumoniae,and it became resistant to imipenem and meropenem.Conclusion This study demonstrated that OMVs isolated from KPC-2-producing CR-KP could deliver bla_(KPC-2)to sensitive K.pneumoniae,allowing the bacteria to produce carbapenemase,which may provide a novel target for innovative therapies in combination with conventional antibiotics for treating carbapenem-resistant Enterobacteriaceae.

Prevalence and Antibiotic Resistance Pattern of <i>Escherichia coli</i>and <i>Klebsiella pneumoniae</i>in Urine Tract Infections at the La Paz Medical Center, Malabo, Equatorial Guinea

The study was conducted to isolate and determine the antibiotic resistance in Escherichia coli and Klebsiella pneumonia from urine samples over a 2-year period (August 2013-September 2015) at the La Paz Medical Center, Malabo. A retrospective analysis of 785 urine culture samples over a 2-year period August 2013-September 2015 was carried out according to the routine protocol of urinalysis. Bacterial etiological agents were isolated from 155 (19.7%) samples with highest prevalence of Escherichia coli (55.5%) followed by Klebsiella pneumonia (23.2%), Proteus mirabilis (4.5%), Pseudomonas species (3.2%), Enterobacter species (2.6%), Enterococcus faecalis (2.6%) and others species (8.4%). The E. coli and K. pneumonia represent 78.7% of all isolated bacterial strains. The E. coli and K. pneumoniae isolates possess highly resistant to ampicillin, Trimethoprim/Sulfamethoxazole, Doxycycline, Amoxicicline/Clavulanic acid. Whereas K. pneumonia demonstrated also to be highly resistant to Gentamycin, Cefuroxime and Ceftriaxon, low level of resistance to Piperacilin/Tazobactam, Amikacin and the lowest to Imipenem. The alarming level of MDR strains to the first choice antibiotics treatment was observed.

Insertion Sequence-Dependent <i>OmpK</i>36 Mutation Associated Ertapenem Resistance in Clinical <i>Klebsiella pneumoniae</i>

Extended-spectrum β-lactamases (ESBLs) and/or AmpC enzymes combined with deficiency of porins OmpK35 and OmpK36 are important for the development of carbapenem-resistant Klebsiella pneumoniae. We characterized the clinical K. pneumoniae human isolates and investigated the effect of meropenem induction on the ompK35 and ompK36 mutation to develop carbapenem resistance from six carbapenem-susceptible ESBL-producing K. pneumoniae strains. 163 clinical K. pneumoniae isolates were grouped mostly into the ESBL + AmpC (44.2%) and ESBL (42.9%) phenotypes. The resistance rate differed between cephalosporins (52.1% for cefepime - 97.5% for cefotaxime) and carbapenems (16% for meropenem - 28.2% for imipenem) (P blaTEM, blaSHV, blaCTX-M-3-like, and blaCTX-M-14-like of AmpA β-lactamase genes and blaDHA and blaCMY of AmpC β-lactamase genes. Compared to all 163 clinical isolates, the 56 carbapenem-resistant isolates carried less frequently of blaTEM, blaCTXM-14-like, and blaCTXM-3-like and more frequently of blaDHA-1 and blaCMY-2. The carbapenem-resistant isolates differed in prevalence against imipenem, ertapenem, and meropenem and lacked OmpK35 more frequently than OmpK36, but abnormal PCR amplicons were detected fewer in the Omp K35-deficient group than in the OmpK36-deficient group (32.5% vs. 68.4%, respectively). The carbapenem-resistant isolate mostly carried blaDHA (91.1%) and three isolates carried blaKPC-2. Following induction with meropenem insertion sequences in ompK36, not ompK36, were identified as IS5 for KP08, IS1 for KP15, and IS903 for KP16 isolates. OmpK36 deficiency increased resistance to ertapenem, but not imipenem and meropenem. Clinical isolates belonged mainly to ESBL + AmpC group and ESBL group with difference in resistance to cephalosporins and carbapenems, the bla genes. Carbapenem resistant isolates lacked OmpK35 expression, than the OmpK36 expression, Meropenem induction developed the carbapenem resistant isolates with insertion of different insertion sequences in ompK36, not ompK35.

Correlation between a Change of Drug Resistance of <i>Klebsiella pneumonia</i>and Defined Daily Doses of Antimicrobial Agents from 2014 to 2018

Introduction: The prevalence of Klebsiella pneumoniae has rapidly increased in recent years and the distribution differed greatly by region, We aimed to study the relationship between antibiotic resistance and K. pneumoniae, especially carbapenem-resistant Klebsiella pneumoniae (CRKP) in our tertiary hospitals from 2014 to 2018. Methodology: The antibiotic consumption data of K. pneumoniae were expressed as the defined daily dose (DDD) per 100 inpatient days (DDDs). K. pneumoniae which isolated from clinical samples in hospital between January 2014 and December 2018 were retrospectively analyzed, and the correlation between antibiotic resistance rate and antibiotic frequency was analyzed. Results: From 2014 to 2018, a total of 2295 strains of K. pneumoniae were isolated, with the detection rates of 8.2%, 9.2%, 11.9%, 13.4% and 14.0%. There were 423 strains of CRKP, with the detection rates of 7.5%, 5.8%, 17.8% 24.2% and 25.2% respectively. K. pneumoniae showed different degrees of resistance to antibiotics and showed an increasing trend year by year to carbapenems. The resistance rate of imipenem was 2.5%, 2.8%, 9.9%, 12.3%, 13.4%, and the resistance rate of meropenem was 2.0%, 3.0%, 8.8%, 12.6%, 12.7%, respectively. The resistance rate of most other drugs decreased. The DDDs values of cefoperazone/sulbactam, piperacillin-tazobactam and gentamicin showed a strong positive correlation with K. pneumoniae drug resistance rate (r > 0.8, P < 0.05). Conclusions: The detection rate of K. pneumoniae and CRKP increased year by year, which was closely related to the dose of antibiotics. Strengthening the management of antimicrobial drugs and standardising the use of antimicrobial prescriptions were of great significance for delaying the emergence of drug-resistant bacteria.

Analysis on clinical distribution and drug resistance of Klebsiella pneumoniae isolated for 5 consecutive years

Objective:To analyze the clinical distribution and drug resistance of Klebsiella pneumoniae isolated from patients in a certain hospital and provide a basis for the rational use of antibiotics in the clinical treatment for the infection of Klebsiella pneumoniae.Methods:1,192 strains of Klebsiella pneumoniae isolated from clinical specimens from 2012 to 2016 were collected.The strains were identified by VITEK-2 Compact Microbiological Identification System,and the corresponding results of the antimicrobial susceptibility test were interpreted in accordance with the standards recommended by Clinical and Laboratory Standards Institute(CLSI).Results:1,192 strains of Klebsiella pneumoniae were mainly isolated from sputum(65.6%),and most of them were from Respiratory Medicine Department and Medical Intensive Care Unit of Respiratory Medicine Department(MICU),accounting for 41.4%.Out of 1,192 strains,448 strains were detected to produce extended-spectrum beta-lactamases(ESBLs),accounting for 37.6%.In addition,the detection rates of ESBL-producing Klebsiella pneumoniae for 5 consecutive years showed an increasing trend year by year,and they were higher than the national average values published by China Antimicrobial Resistance Surveillance System(CARSS)in the corresponding period.The drug resistance rate of ESBL-producing Klebsiella pneumoniae was significantly higher than that of non ESBL-producing strains.Conclusions:The infection caused by Klebsiella pneumoniae mainly occurs in the lower respiratory tract,and the drug resistance rates of Klebsiella pneumoniae to antibiotics in the drug susceptibility spectrum are maintained at a high level.Therefore,the rational selection of antibiotics for the clinical treatment of lower respiratory tract infection caused by Klebsiella pneumoniae must be based on the production of ESBLs and the results of antimicrobial susceptibility test.

Molecular Identification of Co-Existence of Carbapenemase and Extended-Spectrum <i>β</i>-Lactamase Genes in <i>Klebsiella pneumoniae</i>Clinical Isolates, and Their Phylogenetic Patterns in Kenya

The increasing incidence of multidrug-resistant Klebsiella pneumoniae strains has become a serious global healthcare problem. Additionally, the carriage of both extended-spectrum ß-lactamase and carbapenemase genes on plasmid and genomic DNA in K. pneumoniae clinical isolates has not been documented in Kenya. This study aimed to assess the presence of extended spectrum β-lactamase (ESBL) and carbapenemase genes on genomic and plasmid DNA in K. pneumoniae, and classify these super-bug clinical isolates based on their phylogenetic patterns. The identification of Klebsiella-like clinical isolates (n = 20) collected from Kenyatta National Hospital in Nairobi was performed using API 20E Kit. Screening and confirmation for ESBL and carbapenemase phenotypes were conducted using Kirby-Bauer disk diffusion susceptibility test protocol. Conventional PCR technique was used to characterize ESBL and carbapenemase resistant genes on both genomic and plasmid DNA. Subsequently, 16S rRNA gene amplification and sequencing were performed. The 16S rRNA gene contiguous sequences of the bacterial isolates were analyzed using the ChromasPro. The gene sequence was compared with the sequences in GenBank database, using the BLAST program of NCBI to obtain the nearest phylogenetic neighbours from the databases. Then, the sequences of MDR K. pneumoniae and its relatives were aligned using ClustalW. The evolutionary history was inferred by using the maximum likelihood algorithm in MEGA MX. The phenotypic data of antibiotic susceptibility testing revealed that 2/20 (10%) clinical isolates were resistant both to imipenem and meropenem and producers of carbapenemase. These isolates were carbapenemase producers but not extended β-lactamases. However, 3/20 (15%) isolates that co-harboured blaNDM-1, blaIMP, blaTEM, and bla-OXA were identified during genotypic analysis. The positive control used separately yielded the expected band sizes for blaIMP (275 bp), blaOXA-48 (438 bp), and BlaKPC (798). The phylogenetic analysis showed the dual ESBL and carbapenemase producing Klebsiella pneumoniae could be classified as K. pneumoniae strain DSM 30104 and K. pneumonia subsp. pneumoniae strain GMH1080. This study confirmed the co-existence of ESBL and carbapenemase genes in Klebsiella pneumoniae on both bacterial genomic and Plasmid DNA, and demonstrated that the isolates are evolutionarily distinct. These findings raise a concern about the genotypic diversity of antibiotic resistance genes in bacterial isolates and their location. We, therefore, recommend an alternative management approach to combat these MDR bacterial isolates as well as frequent molecular surveillance programs to support antimicrobial stewardship.

Molecular Epidemiology of Klebsiella pneumoniae from Clinical Bovine Mastitis in Northern Area of China,2018–2019

Klebsiella pneumoniae(K.pneumonia,KpⅠ)is a predominate inducement of bovine mastitis,which is associated with high mortality and milk yield reduction.However,data is lacking on the molecular characteristics of bovine K.pneumoniae,limiting the risk assessment of its transmission through the food chain.Herein,we investigated the prevalence of K.pneumoniae in 6301 clinical mastitis(CM)milk samples from dairy cattle in northern area of China.In total,183 K.pneumoniae isolates were recovered,with detection rates of 3.0% and 2.8% in 2018 and 2019,respectively.Like human clinical K.pneumoniae,all CM K.pneumoniae isolates belonged to one of three phylogroups:KpⅠ(n=143),Klebsiella.quasipneumoniae subsp.similipneumoniae(KpⅡ-B)(n=37),and Klebsiella variicola(KpⅢ)(n=3).We detected the extendedspectrum β-lactamase-encoding genes bla_(SHV-2a),blac_(CTX-M-14),and bla_(CTX-M-15),as well as clpC,lpfA,lacI,lacZ,lacY,and the fecABDEIR operon in the KpⅠ isolates,which may contribute to their pathogenicity and host adaptability in cows.The high prevalence of KpⅠ in dairy farms may be problematic,as it showed relatively higher rates of antibiotic resistance and virulence gene carriage than the KpⅡ-B and KpⅢ isolates.Furthermore,we observed distinct differences in population structure between CM-and human infection-associated KpⅠ isolates,with the genes associated with invasive infection in humans rarely being observed in bovine isolates,indicating that few CM-associated K.pneumoniae isolates pose a threat to human health.Nevertheless,bovine KpⅡ-B isolates shared a high level of nucleotide sequence identity with isolates from human infections and frequently carried the nitrogen-fixation gene nif,suggesting an association between KpⅡ-B isolates from cattle and humans,and plant-derived bacteria.

Prevalence of CTXM, SHV, TEM AND OXA Genes among Extended-Spectrum Beta-Lactamase Producing <i>Klebsiella pneumoniae</i>from Mukuru Slum, Kenya

Background: Extended spectrum beta lactamases (ESBLs) producing Enterobacteriaceae cause infections that are often reported in both hospital and community setting. These infections are on the increase and jeopardize the achievement of modern medicine because of their clinical implications. There is need for surveillance measures to be taken, both by the health care personnel and the community at large. Methodology: We examined 330 diarrhea stool samples from children below the age of 5 years and processed them. A total of 96 (29%) samples were identified as Klebsiella pneumoniae out of the bacteria isolated. Identification of ESBL was done and 42 K. pneumoniae isolates were tested for the occurrence of blaCTX-M, blaOXA, blaTEM and blaSHV resistant genes by PCR, gel electrophoresis and visualized by UV illumination. Results: Our results revealed that blaCTXM was the most frequent ESBL type 42 (100%), followed by blaTEM in 41 (97.6%) isolates and blaSHVin38 (90.4%) of the isolates. None of the tested isolates were found to be encoding blaOXA. There was occurrence of more than one gene in most of the isolates. The double combination was detected in blaCTX-M/blaTEM (9.5%) and blaCTXM/SHV (2.4%). A triple combination was noted blaTEM/blaSHV/bla CTX-M (88%). Conclusion: Our results indicate that there is Presence of Beta lactam genes associated with antimicrobial resistance among the K. pneumoniae isolates from Mukuru Slum, Kenya. The predominant ESBL genotype in Mukuru slums, Kenya was blaCTX-M followed by blaTEM and blaSHV respectively. There is need for surveillance measures to be taken so as to control the spread among the community.

Detection of Extended Spectrum β-Lactamase Producing Klebsiella pneumoniae and Escherichia coli in Two Hospitals in the Federal Capital Territory, Abuja, Nigeria

In this study, the prevalence of Extended Spectrum Beta-lactamase (ESBL) producing Klebsiella pneumoniae and Escherichia coli isolates from the University of Abuja Teaching Hospital and the National Hospital was determined. A total of two hundred and fifteen (215) clinical isolates were examined, of which 60% were E. coli and 40% K. pneumoniae respectively. The isolates were collected from various samples namely: Stool, Urine, Pus, High Vagina Swab, Sputum and Wound swab. Out of these isolates, 54 of K. pneumoniae were screened to be ESBL negative and 32 as ESBL positive isolates, while 88 and 40 E. coli were also screened as ESBL negative and ESBL positive isolates respectively. These represent 37.9% of all K. pneumoniae isolates and 31.25% of E. coli isolates respectively. The prevalence of ESBL among the species was not however statistically different (p > 0.05). Multiple resistance in these isolates was common and there is the need for routine screening of ESBL in our hospitals to guide rational and effective use of antibiotics.

碳青霉烯类耐药肺炎克雷伯菌致血流感染风险预测模型的构建

目的构建碳青霉烯类耐药肺炎克雷伯菌(CRKP)致血流感染(BSI)风险预测模型。方法回顾性分析秦皇岛市第一医院2019年1月-2022年6月253例肺炎克雷伯菌致BSI患者的临床资料,将2019年1月-2021年12月收治的患者(223例)作为模型组,2022年1-6月收治的患者(30例)作为验证组。根据是否检出CRKP将模型组患者分为CRKP亚组(56例)和碳青霉烯类敏感肺炎克雷伯菌(CSKP)亚组(167例),对两亚组患者性别、年龄、合并基础疾病等基本信息进行单因素分析和多因素Logistic分析,筛选CRKP致BSI的独立危险因素并构建风险预测模型;以验证组患者为对象,对所建模型进行验证。结果患者入住重症监护病房(ICU)、使用免疫抑制剂和经验性抗感染治疗中使用碳青霉烯类抗菌药物、抗革兰氏阳性球菌药物是CRKP致BSI的独立危险因素(比值比分别为3.749、3.074、2.909、9.419,95%置信区间分别为1.639~8.572、1.292~7.312、1.180~7.717、2.877~30.840,P<0.05);所建风险预测模型的P值为0.365,模型受试者工作特征曲线的曲线下面积(AUC)为0.848(95%置信区间为0.779~0.916,P<0.001),分值临界值为6.5。用于验证组患者时,模型预测的总体准确率为86.67%,其生存曲线的AUC为0.926(95%置信区间为0.809~1.000,P<0.001)。结论患者入住ICU、使用免疫抑制剂和经验性抗感染治疗中使用碳青霉烯类抗菌药物、抗革兰氏阳性球菌药物是CRKP致BSI的独立危险因素;基于上述因素所建的CRKP致BSI风险预测模型的预测准确性良好。

Study of Klebsiella pneumoniae producing extendedspectrum β-lactamases against aminoglycosides

Klebsiella pneumoniae(K.pneumoniae)is one of the main gram-negative bacilli in clini- cal practice.Nosocomial infections caused by K.pneumoniae producing extended-spectrumβ-lactama- ses(ESBLs)are very difficult to treat.This paper investigated the resistant characteristics of K.pneu- moniae producing ESBLs and their aminoglycoside-modifying enzyme gene expressions including N- acetyhransferases and O-adenyhransfemses.Bacteria identification and ESBLs confirmatory tests were performed by Phoenix^(TM)-100 system.And minimum inhibitory concentrations(MICs)of gentamicin, amikacin,kanamycin,tobramycin,netilmicin and neomycin in 53 K.pneumoniae isolates were de- tected by agar dilution.In addition,six aminoglycoside-modifying enzyme genes were amplified by polymerase chain reaction(PCR)and verified by DNA sequencer.It was found that imipenem and meropenem against 120 K.pneumoniae isolates produced powerful antimicrobial activities.The resis- tant rates of gentamicin and amikacin were 55.0% and 46.7%,respectively.Except neomycin, MIC_(50)and MIC_(90)of gentamicin,amikacin,kanamycin,tobramycin and netilmicin in 53 K.pneumoni- ae were all>128μg/ml,and the resistant rates were 83.0%,52.3%,75.5%,81.1% and 69.8%,respectively.However,neomycin was only 39.6%.In addition,five modifying enzyme genes,including aac(3)-Ⅰ,aac(3)-Ⅱ,aac(6')-Ⅰb,ant(3″)-Ⅰ,ant(2″)-Ⅰgenes,were found in 53 isoahes except aac(6')-Ⅱ,and their positive rates were 11.3%,67.9%,47.2%, 1.9% and 39.6%,respectively.It was also confirmed by nucleotide sequence analysis that the above resistant genes shared nearly 100% identities with GenBank published genes.The results obtained in the present study indicated that K.pneumoniae producing ESBLs strains are rapidly spreading in our hospital,and their resistance to aminoglycosides may be associated with aminoglycoside-modifying enz- yme gene expressions.

湖南省细菌耐药监测网2012—2021年克雷伯菌属细菌的耐药性变迁

目的了解湖南省克雷伯菌属细菌和儿童患者分离克雷伯菌属细菌的耐药性变化,为该地区医疗机构合理使用抗菌药物提供依据。方法分析湖南省细菌耐药监测网2012—2021年克雷伯菌属细菌的相关数据,根据美国临床实验室标准化协会(CLSI)M100第32版标准对结果进行判断,应用WHONET 5.6软件对结果进行统计分析。结果2012—2021年湖南省细菌耐药监测网共分离361539株克雷伯菌属细菌,其中肺炎克雷伯菌占86.7%,菌株主要来源于呼吸道标本(66.5%)。2015—2021年克雷伯菌属细菌对亚胺培南和美罗培南的耐药率在10%左右;对替加环素的耐药率下降,2012—2013年的耐药率为7.1%,2018—2021年均<4%;对头孢哌酮/舒巴坦的耐药率2012—2021年上升明显,2020—2021年为13.3%。儿童患者分离的克雷伯菌属细菌2015—2021年对碳青霉烯类药物的耐药率为3.5%~8.6%,2012—2021年对替加环素的耐药率均≤3.8%。2020—2021年新生儿、儿童、成人和老年人患者耐碳青霉烯类克雷伯菌属细菌的检出率分别为4.7%、3.9%、9.5%、10.2%。结论2012—2021年克雷伯菌属细菌对碳青霉烯类药物耐药率较低,但出现了对替加环素耐药的菌株,需引起重视,应合理使用抗菌药物,预防和控制医院感染发生。

IL-1β、IL-18、PMN在老年重症碳青霉烯类耐药肺炎克雷伯菌感染中的表达及其临床意义

目的 探讨老年重症碳青霉烯类耐药肺炎克雷伯菌(CRKP)感染抗菌疗程中白细胞介素-1β(IL-1β)、白细胞介素-18(IL-18)、中性粒细胞(PMN)变化及与疗效关联性。方法 选取2019年1月—2021年3月邯郸市第一医院收治的102例老年重症CRKP感染患者,均给予抗菌药物治疗,根据疗效分为无效组(n=25)、总有效组(n=77),比较两组基线资料、治疗前、治疗5 d后、治疗7 d后IL-1β、IL-18、PMN水平,应用皮尔森(Pearson)相关系数分析治疗5 d后、治疗7 d后IL-1β、IL-18、PMN与疗效关系,采用多因素Logistic回归方程分析疗效的相关影响因素。结果 总有效率组治疗5 d后、治疗7 d后IL-1β[(226.18±58.07)、(169.05±55.34)pg/mL]、IL-18[(57.07±12.29)、(42.66±13.27)ng/L]、PMN[(78.81±10.26)%、(65.48±12.30)%]均低于无效组[(275.34±51.96)、(273.82±49.72)pg/mL]、[(68.47±15.85)、(70.39±20.44)ng/L]、[(87.75±11.05)%、(88.37±10.99)%](F=12.365,P<0.001;F=20.072,P<0.001;F=18.974,P<0.001);治疗5 d后、治疗7 d后IL-1β(r=-0.729、-0.865,均P<0.001)、IL-18(r=-0.711、-0.804,均P<0.001)、PMN(r=-0.804、-0.967,均P<0.001)均与疗效相关;多因素Logistic回归分析显示,校正了混杂因素后,治疗7 d后IL-1β、IL-18、PMN仍是疗效的相关影响因素(P<0.05)。结论 老年重症CRKP感染抗菌疗程中IL-1β、IL-18、PMN变化情况与疗效有关,联合检测有望成为预测患者治疗反应性的生物标志物,从而为临床治疗提供参考。