3年2436株临床分离革兰阴性杆菌对头孢吡肟耐药趋势观察

目的：调查我院1999－2001年间2436株革兰阴性杆菌分离株对第4代头孢菌素头孢吡肟的耐药状况，为临床合理用药提供依据。方法：用K－B法检测头孢吡肟对8种2436株临床分离菌的抑菌环，按1999年NCCLS判断标准得出耐药结果，并与其他3种第3代头孢菌素比较。结果：头孢吡 肟对ESBL阴性大肠杆菌和克雷伯菌属，肠杆菌属，枸橼酸杆菌属，变形杆菌，不动杆菌属，铜绿假单胞菌和嗜麦芽窄食单胞菌等临床主要分离革兰阴性杆菌耐药性变化不大，1999－2001年耐药率分别为20．6％，20．4％和28％，与第3代头孢菌素比较，头孢吡肟，头孢他啶，头孢噻肟，头孢曲松总的细菌耐药率分别为24．6％，26．3％，38．5％和37．0％。结论：头孢吡肟对临床分离的大部分革兰阴性杆菌具有良好的体外抗菌活性，尤其对易产Bush-I型头孢菌素的肠杆菌属的菌株及枸橼酸杆菌属的抗菌活性远优于其他第3代头孢菌素。     

Cefepime-resistant Pseudomonas aeruginosa

Resistance to extended-spectrum cephalosporins complicates treatment of Pseudomonas aeruginosa infections. To elucidate risk factors for cefepime-resistant P. aeruginosa and determine its association with patient death, we conducted a case-control study in Philadelphia, Pennsylvania. Among 2,529 patients hospitalized during 2001-2006, a total of 213 (8.4%) had cefepime-resistant P. aeruginosa infection. Independent risk factors were prior use of an extended-spectrum cephalosphorin (p<0.001), prior use of an extended-spectrum penicillin (p = 0.005), prior use of a quinolone (p<0.001), and transfer from an outside facility (p = 0.01). Among those hospitalized at least 30 days, mortality rates were higher for those with cefepime-resistant than with cefepime-susceptible P. aeruginosa infection (20.2% vs. 13.2%, p = 0.007). Cefepime-resistant P. aeruginosa was an independent risk factor for death only for patients for whom it could be isolated from blood (p = 0.001). Strategies to counter its emergence should focus on optimizing use of antipseudomonal drugs.     

Cefepime MIC as a predictor of the extended-spectrum beta-lactamase type in Klebsiella pneumoniae, Taiwan

To guide selection of carbapenems or fourth-generation cephalosporins as therapy, 110 Klebsiella pneumoniae isolates with extended-spectrum beta-lactamases from Taiwan were characterized by phenotypic (MICs), molecular, and chemical methods. MIC patterns of ceftazidime and cefepime clearly differentiate strains treatable by cefepime and those capable of efficiently hydrolyzing available cephalosporins (CTX-M series and SHV-types). Continued use of cefepime appears to be a treatment option in cases for which MIC results are available and interpreted by the criteria presented.     

Effect of sodium mercaptoacetic acid on different antimicrobial disks in the sodium mercaptoacetic acid double disk synergy test for detection of IMP-1 metallo-β-lactamase-producing Pseudomonas aeruginosa isolates in Japan

We determined the optimal antimicrobial in the sodium mercaptoacetic acid double disk synergy test (SMA-DDST) for the detection of IMP-1-producing Pseudomonas aeruginosa isolates in Japan and evaluated the performance of the test.Fifty-four P. aeruginosa clinical isolates were tested, including 39 IMP-1 producers and 15 non-metallo-β-lactamase (MBL)-producing carbapenem- and ceftazidime (CAZ)-resistant isolates. The SMA-DDST was performed with CAZ, cefepime (CFPM), imipenem (IPM), meropenem (MEPM), doripenem (DRPM), or biapenem (BIPM)-containing disks. The sensitivity of the SMA-DDST with CAZ, CFPM, IPM, MEPM, DRPM, and BIPM was 39/39 (100%), 36/39 (92%), 18/39 (46%), 8/39 (21%), 19/39 (49%), and 36/39 (92%), respectively. The specificity was 15/15 (100%) for all SMA-DDSTs. This suggests that the isolates may have a resistance mechanism other than MBL production for IPM, MEPM, or DRPM. Since the CAZ resistance mechanism in P. aeruginosa is the same as that of CFPM, but differs from that of carbapenems, we conclude that combining CAZ with BIPM SMA-DDSTs can prevent any failure in the detection of IMP-1-producing P. aeruginosa.     

头孢吡肟在胰腺组织及胰液中的浓度测定及其临床意义

目的探讨头孢吡肟在胰腺外科中预防和治疗感染的效果。方法收集从2004年10月至2005年2月各类胰腺疾病手术患者20例,在静脉应用头孢吡肟后,测定血清、胰腺组织和胰液中头孢吡肟浓度。结果头孢吡肟在血清中的平均浓度为(2.23±0.24)μg/ml(0.23~4.66μg/ml),胰液中的平均浓度为(6.52±2.07)μg/ml,胰腺组织中的平均浓度为(10.93±1.52)μg/g;头孢吡肟在胰液中的浓度要高于血清中浓度(6.52μg/ml vs 2.23μg/ml,P=0.046)。头孢吡肟在各种胰腺疾病之间的血清中浓度无差异(P>0.05),但在慢性胰腺炎患者中头孢吡肟在胰液和胰腺组织中的浓度要大于其他疾病患者(P<0.05)。结论头孢吡肟能有效地通过血胰屏障,对于胰腺疾病和胰腺手术患者可起到良好的预防和治疗感染效果。     

CEFEPIME VERSUS CETAZIDIME AMIKACIN AS EMPIRICAL THERAPY FOR FEBRILE NEUTROPENIA IN CHILDREN WITH CANCER: A Prospective Randomized Trial of the Treatment Efficacy and Cost

The efficacy, safety, and cost of cefepime and ceftazidime + amikacin as empirical therapy in children with febrile neutropenia is compared. A prospective randomized study in children with cancer was conducted. Patients were randomly assigned to receive either cefepime 150 mg/kg/day or ceftazidime 150 mg/kg/day combined with amikacin 15 mg/kg/day. Treatment modification was defined as all the changes in the empirical antimicrobials after the first 72 h. Overall treatment success was defined as cure of febrile episode with or without modification. Costs of hospitalization, antimicrobial drugs, and supportive therapy were calculated. Fifty febrile netropenic episodes were evaluated. Infectious agents were microbiologically identified in 28% of episodes. The incidence of gram-negative and gram-positive isolates was equal. Overall treatment success was 100% and success of initial empirical therapy without modification was 52 and 40% in the cefepime and cefepime + amikacin groups, respectively. The response rate after glycopeptides were added to the regimen was 64 and 52% in the cefepime and cefepime + amikacin arms, respectively. Glycopeptide and antifungal drugs were added more frequently in the ceftazidime + amikacin group. Duration of fever, hospitalization, and antimicrobial drug administration were longer in the ceftazidime + amikacin arm. The costs of the antimicrobial drugs, hospitalization, and total cost were lower in the cefepime arm. Cefepime monotherapy is as effective as ceftazidime + amikacin combination in febrile neutropenia of pediatric cancer patients and must be preferred due to shorter defervescence of fever, shorter hospitalization, and lower therapy cost.     

头孢吡肟对多重耐药铜绿假单胞菌体外联合药物敏感试验研究

探讨头孢吡肟(FEP)分别与美罗培南(MEM)和环丙沙星(CIP)联合应用对多重耐药铜绿假单胞菌(MDRPA)的体外抑菌作用的影响,为临床治疗MDRPA提供依据。方法 采用棋盘法设计,通过琼脂平板稀释法测定抗菌药物对58 株临床分离的MDRPA 的最低抑菌浓度(MIC),通过计算分级抑菌浓度指数评价药物体外联合抑菌效果。结果 FEP与MEM联合后,表现为协同作用的为32.8%,相加作用的为46.6%,无关作用的为20.6%,无拮抗作用;FEP 与CIP联用后,表现为协同作用的为20.7%,相加作用的为51.7%,无关作用的为27.6%,无拮抗作用。联合应用的药物组合,各药MIC₅₀ 均明显降低,浓度-累积抑菌率曲线均表现为左移。结论 FEP分别与MEM和CIP联用均可以提高各自对MDRPA抗菌作用的敏感性。     

头孢他啶与头孢吡肟治疗药物监测的高效液相色谱方法探索及其临床采样流程建立

目的： 建立同时测定头孢他啶和头孢吡肟血药浓度的高效液相色谱（high performance liquid chromatography,HPLC）法及其临床采样流程,并应用于临床治疗药物监测。方法： 采用CAPCELL PAK C₁₈（4.6 mm×250 mm,5.0 μm）色谱柱进行色谱分离,流动相A为50 mmol·L^-1磷酸二氢钾溶液,流动相B为混合有机相（乙腈：甲醇：水=7：2：1）,A：B（V/V,93：7）,流速1.0 mL·min^-1,波长为254 nm,盐酸雷尼替丁为内标,以ACP-1去蛋白剂沉淀蛋白,旋涡离心后进样30 μL分析,同时考察全血中两药在不同抗凝管、不同温度下放置不同时间的稳定性。结果： 头孢他啶和头孢吡肟的血浆质量浓度线性范围分别是0.57~267.34 μg·mL^-1、0.54~208.49 μg·mL^-1,低、中、高质控样品的日内、日间精密度均小于15%,萃取回收率分别为90.9%~95.4%、88.6%~97.7%;全血稳定性试验中,以EDTA-K2管采血的头孢他啶与头孢吡肟血浆在6℃及24℃下均能稳定48 h,37℃下稳定10 h;而以肝素钠管采血的头孢他啶和头孢吡肟血浆在6℃及24℃下能稳定24 h,37℃下能稳定4 h。结论： 所建立的方法具有灵敏度高、稳定性好、操作简便等优点,并根据全血稳定性结果建立了一套临床采样流程,为头孢他啶和头孢吡肟的TDM标准化与规范化建设提供参考依据。     

Comparison of drug susceptibility between Escherichia coli detected in stool cultures of patients undergoing transrectal prostate needle biopsy and Escherichia coli in hospital-wide urine antibiograms

A prostate biopsy is essential for prostate cancer diagnosis. However, infections are one of the biopsy-associated complications, and post-biopsy fever is estimated to occur in approximately 1% of all cases. It may thus be beneficial to perform a rectal swab culture before a transrectal prostate biopsy to confirm the presence of resistant bacteria and select preventive antibacterial agents according to the drug susceptibility results. This study aimed to determine whether there is a difference between the drug susceptibility of bacteria detected in the stool of patients who were scheduled to undergo prostate biopsy and the hospital-wide urine antibiogram. Patients suspected of having prostate cancer who underwent transrectal prostate biopsy via transrectal ultrasonography between August 1, 2016, and June 30, 2020, were included in this study. Stool samples were collected and cultured before biopsy. Overall, 99 patients underwent prostate biopsy, and of these, culture results were available for 81 patients (81.8%). Escherichia coli was detected in 74.0% (60 samples) of the stool culture samples, of which 4 samples were extended-spectrum β-lactamase-producing types. We found greater susceptibility of Escherichia coli to ampicillin, fluoroquinolones, sulfamethoxazole/trimethoprim, and cefixime in the stool culture antibiogram than in the hospital-wide urine antibiogram. We also found a significantly low incidence of ESBL-positive Escherichia coli in the stool culture antibiogram with p-values of 0.009, 0.007, and 0.03 compared to the hospital-wide urine antibiograms for 2017, 2018, and 2019, respectively. Stool culture of prostate cancer patients undergoing biopsy may provide useful information for selecting prophylactic antimicrobial agents.