Sepsis probada a Klebsiella oxytoca en un recién nacido

La sepsis neonatal constituye una de las principales causas de muertes neonatales en los países en desarrollo, con datos que estiman más de un millón de muertes en todo el mundo cada año. Se persigue presentar un caso, dada la infrecuencia de la sepsis neonatal tardía por Klebsiella oxytoca. Se trata de una paciente femenina, pretérmino y de bajo peso al nacer, que a los 17 días de vida comenzó con deterioro de su estado clínico dado por hipoactividad, palidez cutánea, succión morosa e incremento de la circunferencia abdominal, acompañados de disfunción hematológica severa dada por anemia, trombocitopenia y neutropenia, que requirió varias transfusiones con hemoderivados y terapéutica antimicrobiana combinada (primero con meronem y amikacina, luego con ciprofloxacina y vancomicina). Se trató también con antifúngicos, diuréticos, drogas vasoactivas, ventilación mecánica y eritropoyetina. Se interconsultó con Cardiología e Infectología pediátricas. Tuvo finalmente una evolución satisfactoria, con lactancia materna efectiva. El incremento de la sepsis en neonatos hospitalizados y la resistencia bacteriana son problemas de salud pública. Es importante reconocer los factores de riesgo para la sepsis en este grupo de pacientes, para su tratamiento oportuno.

Neonatal sepsis is one of the main causes of neonatal deaths in developing countries, with data estimating more than one million deaths around the world every year. The aim is to present case a case, given the infrequency of late neonatal sepsis by Klebsiella oxytoca. This is the case of a pre-term female patient, with low weight at birth, who at 17 days of birth began with deterioration of her clinical status due to hypo-activity, skin paleness, morose suction and increase in abdominal circumference, accompanied by severe hematological dysfunction given by anemia, thrombocytopenia and neutropenia, which required several transfusions with blood products and combined antimicrobial therapeutic (first with meronem and amikacin, then with ciprofloxacin and vancomycin). She was also treated antifungals, diuretics, vasoactive drugs, mechanical ventilation and erythropoietin. She was consulted with Pediatric Cardiology and Infectious diseases. Finally she had a satisfactory evolution, with effective maternal breastfeeding. Sepsis increase in hospitalized neonates and bacterial resistance are public health problems. It is important to recognize the risk factors for sepsis in this group of patients, for their timely treatment.

Exopolysaccharides from Klebsiella oxytoca: anti-inflammatory activity

Abstract Exopolysaccharides (EPS) produced by Klebsiella oxytoca are of environmental, pharmaceutical, and medicinal interest. However, studies about the anti-inflammatory activity of EPS produced by this microorganism still remain limited. The aim of this study was to produce, characterize, and evaluate the anti-inflammatory activity of EPS from K. oxytoca in a pleurisy model. Colorimetric analysis revealed that precipitated crude exopolysaccharides (KEPSC) and deproteinated exopolysaccharides (KEPS) present high levels of total carbohydrates (65.57% and 62.82%, respectively). Analyses of uronic acid (7.90% in KEPSC and 6.21% in KEPS) and pyruvic acid (3.01% in KEPSC and 1.68% in KEPS) confirm that the EPS are acidic. Gas chromatography-mass spectrometry analyses demonstrated that the EPS consisted of rhamnose (29.83%), glucose (11.21%), galactose (52.45%), and mannose (6.50%). The treatment of an experimental pleurisy model in rats through subcutaneous administration of 50, 100, 200, and 400 mg/kg of KEPS decreased both the volume of inflammatory exudate and the number of leukocytes recruited to the pleural cavity. The present data showed that EPS production by K. oxytoca using the method described is easy to perform and results in a good yield. In addition, we show that KEPS exhibit anti-inflammatory activity when administered subcutaneously in rats.

A case of late-onset Klebsiella oxytoca keratitis treated with topical imipenem after deep anterior lamellar keratoplasty / Caso de ceratite de início tardio por Klebsiella oxytoca tratado com imipenem tópico após ceratoplastia lamelar anterior profunda

ABSTRACT The aim of this study was to discuss a case of late-onset Klebsiella oxytoca keratitis after deep anterior lamellar keratoplasty and its treatment. A 21-year-old female patient presented with redness and effluence in the left eye at 5 months after uncomplicated deep anterior lamellar keratoplasty surgery. In the examination, a single suture was loosened in the superior nasal region and there was an infiltration area and epithelial defect in the graft and recipient bed junction in the area of the loose suture. Topical fortified vancomycin and fortified ceftazidime treatment was started empirically hourly, but there was insufficient response. After K. Oxytoca growth in a swab and suture culture taken from the patient, fortified vancomycin was replaced with fortified imipenem. It was observed that the infiltration area rapidly regressed and the epithelial defect was closed after fortified imipenem treatment. Fortified imipenem may be considered as an alternative treatment, especially in cases in which there is no response to treatment and culture growth is detected.(AU)

RESUMO O objetivo deste estudo é discutir um caso de ceratite tardia por Klebsiella oxytoca, após ceratoplastia lamelar anterior profunda, bem como seu tratamento. Uma paciente de 21 anos apresentou vermelhidão e efluxo no olho esquerdo 5 meses após cirurgia de ceratoplastia lamelar anterior profunda sem complicações. Ao exame, havia uma única sutura solta na região nasal superior e uma área de infiltração com defeito epitelial no enxerto e na junção com o leito receptor na área da sutura solta. Iniciou-se empiricamente um tratamento tópico com vancomicina e ceftazidima fortificada de hora em hora, porém com resposta insuficiente. Após o crescimento de K. oxytoca a partir de cultura de swab e sutura retirados da paciente, a vancomicina fortificada foi substituída por imipenem fortificado. Observou-se que a área de infiltração regrediu rapidamente e que o defeito epitelial foi fechado com o tratamento com imipenem fortificado. O imipenem fortificado pode ser considerado um tratamento alternativo, especialmente nos casos sem resposta ao tratamento e detecção de crescimento na cultura.(AU)

Enfermedad Tromboembólica Venosa Asintomática en un paciente con síndrome de Down: Reporte de un caso y presentación clínica / Asymptomatic Venous Thromboembolic Disease in a patient with Down syndrome: A case report and clinical presentation

Introducción:Los trastornos vasculares son frecuentes en el Síndrome de Down (SD); sin embargo, no está claro si dichos pacientes tienen un mayor riesgo de eventos tromboembólicos venosos, lo que hace una asociación poco frecuente. Se reporta el caso de una paciente del sexo femenino, Caso clínico:adulto joven, de 27 años con SD que presentó un émbolo central de gran dimensión en la arteria pulmonar y su rama lobular media del lado derecho; asimismo, un trombo en la arteria femoral que taponaba casi completamente su diámetro, cuya presentación es asintomática; siendo diagnosticados por Angiotomografía y ecografía doppler correspondientemente. Se suministró como tratamiento Enoxaparina y Warfarina, teniendo una evolución favorable. Conclusión:Sedebeprestarmuchaatenciónalacorrelaciónentre enfermedad tromboembólica venosa y síndrome de Down, y ampliar esfuerzo en su prevención, detección y tratamiento.

Introduction:Vascular disorders are frequent in Down Syndrome (SD); however, it is unclear whether such patients are at increased risk for venous thromboembolic events, making this association rare. We Clinical case:report the case of a 27-year-old female patient with DS who presented a large central embolus in the pulmonary artery and its middle lobular branch on the right side; likewise, a thrombus in the femoral artery that almost completely blocked its diameter, whose presentation is asymptomatic; being diagnosed by CTAngiography and Doppler ultrasound accordingly. Enoxaparin and Warfarin were given as treatment, having a favorable evolution. Much Conclusion:attention should be paid to the correlation between venous thromboembolic disease and Down syndrome, and a wide effort should be made in its prevention, detection and treatment

Enfermedad Tromboembólica Venosa Asintomática en un paciente con síndrome de Down: Reporte de un caso y presentación clínica / Asymptomatic Venous Thromboembolic Disease in a patient with Down syndrome: A case report and clinical presentation

RESUMEN Introducción: Los trastornos vasculares son frecuentes en el Síndrome de Down (SD); sin embargo, no está claro si dichos pacientes tienen un mayor riesgo de eventos tromboembólicos venosos, lo que hace una asociación poco frecuente. Caso clínico: Se reporta el caso de una paciente del sexo femenino, adulto joven, de 27 años con SD que presentó un émbolo central de gran dimensión en la arteria pulmonar y su rama lobular media del lado derecho; asimismo, un trombo en la arteria femoral que taponaba casi completamente su diámetro, cuya presentación es asintomática; siendo diagnosticados por Angiotomografía y ecografía doppler correspondientemente. Se suministró como tratamiento Enoxaparina y Warfarina, teniendo una evolución favorable. Conclusión: Se debe prestar mucha atención a la correlación entre enfermedad tromboembólica venosa y síndrome de Down, y ampliar esfuerzo en su prevención, detección y tratamiento.

ABSTRACT Introduction: Vascular disorders are frequent in Down Syndrome (SD); however, it is unclear whether such patients are at increased risk for venous thromboembolic events, making this association rare. Clinical case: We report the case of a 27-year-old female patient with DS who presented a large central embolus in the pulmonary artery and its middle lobular branch on the right side; likewise, a thrombus in the femoral artery that almost completely blocked its diameter, whose presentation is asymptomatic; being diagnosed by CT Angiography and Doppler ultrasound accordingly. Enoxaparin and Warfarin were given as treatment, having a favorable evolution. Conclusion: Much attention should be paid to the correlation between venous thromboembolic disease and Down syndrome, and a wide effort should be made in its prevention, detection and treatment.

Antimicrobial Susceptibility Pattern of Klebsiella Species from Various Clinical Samples at a Tertiary Care Hospital

The aim of the study was to investigate the antimicrobial susceptibility pattern of Klebsiellaspecies from different clinical samples at Sree Balaji Medical College and Hospital, India. Overall 189 samples out of 980 non repetitive clinical samples obtained from wound/pus, urine, sputum swab and blood by disc diffusion method and identified as Klebsiellaand analysed. Out of total 189 Klebsiellaisolates, 76 out of 155 K. pneumoniae(49%)were resistant and none out of 34 Klebsiella oxytoca(0%) showed resistance to cefotaxime and ceftazidime by disc diffusion method. Antimicrobial susceptibility testing of Klebsiellaexhibited 100% resistance to Ampicillin. The present study highlights the need for the continued monitoring of antimicrobial susceptibility patterns of important bacterial pathogens, so that rational antibiotic policies can be formulated

Antibiotics-Associated Hemorrhagic Colitis Caused by Klebsiella oxytoca: Two Case Reports / 대한소아소화기영양학회지

Nowadays, Klebsiella oxytoca is described as a causative organism for antibiotic-associated hemorrhagic colitis (AAHC). Here we report two cases of pediatric AAHC, from which K. oxytoca was cultured after starting amoxicillin-clavulanate or amoxicillin treatment. The patients developed severe abdominal pain and a large amount of bloody diarrhea. K. oxytoca was obtained in intestinal fluid culture of a boy through the colonoscopy. On the other hand, colonic tissue culture and intestinal fluid culture were negative of the other patient. K. oxytoca was detected in stool culture when he was admitted. These cases showed characteristic endoscopic findings of segmental hemorrhagic colitis, and both boys recovered spontaneously within 2–3 days after they stopped taking the antibiotics. Therefore, in children who develop relatively large amount of bloody diarrhea after antibiotic treatment, we should consider AAHC caused by K. oxytoca.

Study on the Resistance Mechanisms of Carbapenem-Resistant Klebsiella Oxytoca / 现代检验医学杂志

Objective To investigate the resistance mechanism of Carbapenem-Resistant Klebsiella oxytoca.Methods Car-bapenem-Resistant Klebsiellaoxytoca were collected from Fujian Medical University Union Hospital.The modified hodge test (MHT)was used for carbapenemase phenotype screening.The minimum inhibit concentration(MIC)was detected using agar dilution method for 1 7 drugs.PCR and DNA sequencing were used to detect commonβ-Lactamase genes and carbapene-mases genes.Conj ugation experiments demonstrated the transferability of the carbapenem-resistant determinants.Results 5 Carbapenem-Resistant Klebsiella oxytoca of 4 isolates were positive detected by MHT.Minimum inhibit concentration was detected by using agar dilution method for 17 drugs.More than 80% isolates were resistance to nine drugs.2 isolates conju-gated successfully of 5 Carbapenem-Resistant Klebsiella oxytoca Isolates.There were 2 isolates included carbapenemases gene (1 isolates were only IMP producers,1 isolate contained the IMP and KPC),3 isolates produce ESBLs gene.Conclution The due to CRE strains isolated from Fujian Medical University Union Hospital may be metallo-enzyme carbapenemase and KPC gene.And the isolate that produce two Carbapenem-Resistant gene had been found in this hospital.

Study on dynamic changing regularity of microflora in fermentation process of Sojae Semen Praeparatum by PCR-DGGE / 中草药

Objective: To reveal the dynamic changing regularity of microflora in the fermentation process of Sojae Semen Praeparatum (SSP) and lay the foundation for revealing the mechanism of SSP processing by denaturing gradient gel electrophoresis (DGGE). Methods: The dynamic changes of microflora, both bacteria and fungi in fermentation process were monitored by PCR-denaturing gradient gel electrophoresis. According to the unweighted pair group method using arithmetic average clustering, the samples of SSP in various stages were analyzed. Results: Bacterial flora had diversity, and Aspergillus was the major fungus in the first stage called "yellow cladding". The major bacteria was Lactobacillus, while the major fungus was Cryptococcus at the "secondary fermentation" stage. The major microorganism was Bacillus subtillis and Pseudomonas putida on day 1, and Stenotrophomonas maltophilia, Sphingobacterium sp, and A. oryzae on day 3. Then on day 6, B. amyloliquefaciens, Aspergillus, and Trichosporon ovoides became the primary microorganisms. B. subtillis, T. ovoides, and A. niger were the major microorganism on day 3 of "secondary fermentation". On day 9 of this stage, the major strains were B. subtilis, L. concavus, L. nasuensis, and Cryptococcus randhawi. On day 15 of "secondary fermentation", they were B. subtilis, L. concavus, C. randhawi, Trichosporon, and two fungi cannot be cultured. Klebsiella oxytoca, B. subtilis, and L. concavus were dominant strains in the whole fermentation process. The composition of microflora in "yellow cladding" stage was different to that of the "secondary fermentation". The microbial community on day 3 and 6 was similar to 76.4%. While the lowest similarity between the samples on day 3 and 9, it was similar to 24.5% during samples on day 6 and 9 in "secondary fermentation" stage. The highest similarity of fungal composition was between day 3 and 6 samples, and the lowest one was between day 3 and 15 of "secondary fermentation", which was similar to 11.2% only. Conclusion: The results show that the unique flavor and function of SSP may be determined by the dynamic microbial communities and microbial flora in the fermentation process, and the secondary fermentation is proved to be irreplaceable from the microbiological point of view.

Death caused by ST19 Klebsiella oxytoca with wcaG virulence gene in leukemic patient / 中国人兽共患病学报

We investigated the cause of a leukemia patient induced by infect in a strain of Klebsiella oxytoca with hypermucoviscosity (HMV) phenotype.Identification and drug susceptibility of the isolate were carried out with VITEK-2 compact system.HMV phenotype was detected by string-test.The major high virulence capsular serotypes (K1,K2,K5,K20,K54 and K57) and virulence factors (rmpA,wcaG,allS,kfu,aerobactin,fimH,uge,wabG and cf29a) were detected by polymerase chain reaction and DNA sequencing.Molecular typing was performed by multilocus sequence typing (MLST).Results showed that the isolates of blood and lung tissue were Klebsiella oxytoca belonged to ST 19,which were sensitive to the antibiotics used in test,expressing the HMV phenotype.The virulence gene wcaG was found,while other virulence genes and the major high virulence capsular serotypes were negative.It indicates that ST19 Klebsiella oxytoca with wcaG virulence gene is the main reason causing leukemic patient death.

Heterologous expression and characterization of Klebsiella oxytoca lysine decarboxylase / 生物工程学报

Cadaverine is a biogenic amine that has the potential to become an important platform chemical for the production of industrial polymers, such as polyamides and polyurethanes. We reported here a lysine decarboxylase from Klebsiella oxytoca. The lysine decarboxylase from Klebsiella oxytoca was cloned to Escherichia coli to get the strain LN18. The specific activity of the crude protein from LN18 reached 30 000 U. The molecular weight was about 80 kDa. The optimum temperature and pH of the crude protein were 55 ℃ and 5.5 respectively. The specific activity could keep over 30% at pH 8.0 compared the one at pH 5.5, much difference from Escherichia coli lysine decarboxylase CadA. Mg²⁺ was positive to the specific activity, whereas Fe²⁺, Zn²⁺ and Ca²⁺ were negative.

Isolation and characterization of an SDS-degrading Klebsiella oxytoca.

Sodium dodecyl sulfate (SDS) is one of the main components in the detergent and cosmetic industries. Its bioremediation by suitable microorganism has begun to receive greater attention as the amount of SDS usage increases to a point where treatment plants would not be able to cope with the increasing amount of SDS in wastewater. The purpose of this work was to isolate local SDS-degrading bacteria. Screening was carried out by the conventional enrichment-culture technique. Six SDS-degrading bacteria were isolated. Of these isolates, isolate S14 showed the highest degradation of SDS with 90% degradation after three days of incubation. Isolate S14 was tentatively identified as Klebsiella oxytoca strain DRY14 based on carbon utilization profiles using Biolog GN plates and partial 16S rDNA molecular phylogeny. SDS degradation by the bacterium was optimum at 37oC. Ammonium sulphate; at 2.0 g l-1, was found to be the best nitrogen source for the growth of strain DRY14. Maximum growth on SDS was observed at pH 7.25. The strain exhibited optimum growth at SDS concentration of 2.0 g l-1 and was completely inhibited at 10 g l-1 SDS. At the tolerable initial concentration of 2.0 g l-1, almost 80% of 2.0 g l-1 SDS was degraded after 4 days of incubation concomitant with increase in cellular growth. The Km (app) and Vmax (app) values calculated for the alkylsulfatase from this bacterium were 0.1 mM SDS and 1.07 >mol min-1 mg-1 protein, respectively.

A case of liver abscess due to Klebsiella oxytoca / 대한내과학회지

Klebsiella are opportunistic pathogens that cause a wide spectrum of severe diseases, such as septicemia, pneumonia, urinary tract infection, and soft tissue infection. Klebsiella oxytoca is rarely isolated from human clinical specimens, and bacteremia due to Klebsiella oxytoca remains relatively uncommon. We experienced a case of liver abscess due to Klebsiella oxytoca in a 71-year-old male with a history of pylorus-preserving pancreaticoduodenectomy (PPPD) 4 years earlier. The patient was diagnosed with hemobilia secondary to a pseudo-aneurysm at the lower pole of the abscess cavity during antibiotic treatment and was treated successfully with selective percutaneous transcatheter embolization

Assessment of genetic relationship between Klebsiella pneumoniae and Klebsiella oxytoca samples isolated from a dental office

The present study aimed to analyze the genetic similarity between genomic profiles of thirteen Klebsiella oxytoca and seven Klebsiella pneumoniae samples isolated from two different collections carried out in different places of dental offices. Random amplified polymorphic DNA (RAPD) technique and similarity coefficients (calculated by Sorensen-Dice and simple matching) were applied to determine their genetic profile of randomic DNA sequences. The majority of the isolates of K. pneumoniae and K. oxytoca presented similar coefficient values (¡Ý 0.80). Thus, it was possible to identify that strain dissemination occurred mainly via the hands of the surgeon-dentists and, finally, to determine the genetic similarity of the strains from dental office environments.(AU)

Pseudo-outbreak of Klebsiella oxytoca fromBronchial Washing Specimens / 대한임상미생물학회지

BACKGROUND: We noticed a sudden increase in the isolation of Klebsiella oxytoca from bronchial washing specimens during May to June 2006. An epidemiological investigation was conducted to identify the cause of the outbreak and to implement appropriate infection control measures. METHODS: A total of 18 isolates of K. oxytoca were found. The 14 bronchial washing specimens that yielded K. oxytoca were taken in the outpatient bronchoscopy suite, and the other 4 specimens were obtained by a portable bronchoscopy. The medical records and microbiologic findings of these patients were reviewed. Environmental samples from two bronchoscopes and the bronchoscopy suite were cultured. The relations between the available 10 isolates from bronchial washing fluid were investigated by pulsed-field gel electrophoresis (PFGE). RESULTS: No patients were judged to have had true infections attributable to K. oxytoca either before or after bronchoscopy. Cultures of samples from two bronchoscopes and related environment did not grow K. oxytoca. The PFGE analysis showed that 8 of 10 isolates had a similar pattern of DNA fragments. An infection control strategy was implemented, including adequately cleaning and disinfecting the bronchoscopes, and a sharp reduction in the incidence of K. oxytoca from bronchial washing samples followed. CONCLUSION: The sudden increase of K. oxytoca from bronchial washing specimens was a pseudo-outbreak. We presumed that the bronchoscopes became contaminated during a procedure in a patient colonized with K. oxytoca in the upper-respiratory tract.

Isolation Frequency of Extended Spectrum beta-Lactamase Producing Escherichia coli, Klebsiella species, and Proteus mirabilis / 대한임상미생물학회지

BACKGROUND: Accurate detection of extended spectrum beta-lactamase (ESBL) is important because ESBLproducing organisms may appear susceptible to oxyimino- beta-lactams in standard susceptibility tests, but are considered to be clinically resistant to these drugs. And continued monitoring of isolation trend of ESBL-producing organisms is essential for the guideline settlement of antibiotic usage and infection control program. METHODS: Disk diffusion test using the Clinical and Laboratory Standards Institute's ESBL phenotypic confirmatory test were performed on 5,511 clinical isolates of Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, and Proteus mirabilis during the recent six years (April 2001-March 2007). The ESBL producer was defined as an organism showing an increase in the zone diameter of > or =5 mm for either cefotaxime or ceftazidime with clavulanic acid versus that without clavulanic acid (CTC confirmatory test, CZC confirmatory test, respectively). RESULTS: The ESBL-positive rates were 34.8% in K. pneumoniae, 9.3% in K. oxytoca, 8.4% in E. coli, and 6.5% in P. mirabilis. Among the ESBL-positive organisms, the detection rates of ESBL CTC and CZC confirmatory tests were as follows: 91.3% vs 68.7% in K. pneumoniae, 96.3% vs 44.4% in K. oxytoca, 94.8% vs 45.4% in E. coli, and 100% vs 20% in P. mirabilis. ESBL-producing K. pneumoniae had shown a continuously increasing trend from 24.3% in 2001 to 46.4% in 2006. CONCLUSION: Both of the ESBL confirmatory tests should be simultaneously tested for the accurate detection of ESBL-producing K. pneumoniae, K. oxytoca, E. coli, and P. mirabilis. In addition, an active infection control approach is needed for ESBL-producing K. pneumoniae.

Genes of Extended Spectrum ?-Lactamases and AmpC ?-Lactamase from Klebsiella pneumoniae and Klebsiella oxytoca / 中华医院感染学杂志

OBJECTIVE To study the phenotypic existence,genetic type and gene transfer of extended spectrum beta-lactamases(ESBLs) and AmpC beta-lactamase from Klebsiella pneumoniae and K.oxytoca. METHODS Disk confirmation test and 3-aminophenylboronic acid(APB) disk potentiation test were used to detect ESBLs and AmpC beta-lactamase.The genetic types of these two kinds of beta-lactamases were examined by gene chip technology and sequence analysis.The transfer of resistance genes was conducted by conjugation. RESULTS From 72 strains of K.pneumoniae and 20 strains of K.oxytoca which were not susceptible to cefoxitin,coexistence of AmpC(beta-lactamase) with ESBLs together was very common,accounted for 54.2% and 75.0%,single ESBLs accounted for 22.2% and 25.0%,respectively.There were 12.5% single AmpC in(K.pneumoniae).DHA type ampC gene and SHV type ESBLs gene were the main molecular types.These genes could be transferred from clinical isolates to recipient E.coli J53. CONCLUSIONS ESBLs as well as AmpC(beta-lactamase) are the most important resistance mechanism in K.pneumoniae and K.oxytoca.The resistance could be transferred through the bacterial conjugation.

Integrons Containing IMP-4 Metallo-?-lactamases(MBLs) Gene among Multiple-drug-resistant Klebsiella oxytoca Strains / 中华医院感染学杂志

OBJECTIVE To analyze the sequence of IMP-4 metallo-?-lactamases(MBLs) encoding gene from clinical isolates of multiple-drug-resistant Klebsiella oxytoca strains and attempt to know the integrons composing the drug resistance gene box.METHODS The antibiotic sensitivity test of multi-resistant K.oxytoca strains was done according to Kirby-Bauer method of CLSI 2005,and the double disk synergy test and Etest were for detecting their MBLs.The Class 1 integrons were detected by PCR.The purified amplicons of Class l integrons were sequenced.The type and order of gene cassettes in integrons were analyzed by searching GenBank.RESULTS The K.oxytoca was resistant to carbapenems,the third-generation cephalosporins,cefoxitin,quinolones,cefoperazone/sulbactam,sulfamethoxazole/trimethoprim,amoxicillin/clavulanate,ticacillin/clavulanate,piperacillin,cefepime,rifampicin and piperacillin/tazobatam,only susceptible to amikacin and polymyxin B.The IMP-4 metallo-?-lactamases,aadA1,AmpC,CTX-M-14,qacE△1-sull and intI1 were positive.CONCLUSIONS Integrons are important molecular mechanism in the development of multidrug resistance.There are resistance gene boxes in them.

Isolation of Klebsiella Oxytoca Clinical Isolate Producing AmpC beta-lactamase, DHA-1 / 대한임상미생물학회지

BACKGROUND: Klebsiella oxytoca strain exhibiting an unusual inducible beta-lactam resistance phenotype was isolated from a wound specimen of a patient at a university hospital in August 2002. The isolate was resistant to ampicillin, ampicillin-sulbactam, cephalothin, cefoxitin, and demonstrated reduced inhibition zone diameters for ceftazidime in combination with clavulanate versus those for ceftazidime when tested alone. METHODS: Antimicrobial susceptibilities were tested using the Etest and disk diffusion method. AmpC beta-lactamase production was determined by modified Hodge test. The disk antagonism method was used to detect inducibility of beta-lactamase. Conjugation experiments were performed by the filter mating method using the recipient Escherichia coli J53 Azir strain. PCR and DNA sequencing of DHA-specific PCR products were tested. RESULTS: The double disk synergy test was negative and the modified Hodge test was positive for the K. oxytoca isolate. Antagonism was observed between cefoxitin and oxyimino-cephalosporins. Sequence analysis of the DHA-specific PCR products revealed that they were identical to the amino acid sequence of the DHA-1 beta-lactamase. Transfer of the resistance by conjugation experiments was successful. CONCLUSIONS: We found a plasmid-mediated DHA-1 beta-lactamase-producing K. oxytoca possessing an unusual inducible beta-lactam resistance phenotype was found in a university hospital in Korea. The resistance phenotype was conferred by DHA-1 encoded by a self-transferable plasmid.