湖南省细菌耐药监测网2012—2021年铜绿假单胞菌耐药性监测报告

目的 了解2012—2021年湖南省细菌耐药监测网监测医院临床分离铜绿假单胞菌的分布及耐药性变迁情况。方法 采用纸片扩散法或自动化仪器法对临床分离株作药物敏感性(药敏)试验,按美国临床实验室标准化协会(CLSI)2022年版标准判断药敏试验结果,并应用WHONET 5.6软件进行统计分析。应用SPSS对数据进行趋势性检验(Cochran-armitage)及卡方检验。结果 2012—2021年湖南省耐药监测网共监测铜绿假单胞菌176 441株,其中,99.4%的菌株分离自住院患者,约70%的菌株分离自呼吸道标本;儿童(0～17岁)来源的铜绿假单胞菌占8.4%,成人来源的占91.6%。药敏结果显示,10年间铜绿假单胞菌对多黏菌素B最敏感,耐药率低于6%,对哌拉西林、哌拉西林/他唑巴坦、头孢他啶、头孢吡肟、氨曲南、亚胺培南、阿米卡星、庆大霉素、妥布霉素、环丙沙星、左氧氟沙星、多黏菌素B的耐药率均呈下降趋势。共检出耐碳青霉烯类铜绿假单胞菌(CRPA)29 920株,该省CRPA 10年的平均分离率为18.0%。成人CRPA检出率为18.5%,高于儿童的12.3%,均呈下降趋势。结论 湖南省临...     

全国细菌耐药监测网2014—2019年临床分离非发酵革兰阴性杆菌耐药性变迁

目的了解全国临床分离非发酵革兰阴性杆菌的耐药性变迁。方法按照全国细菌耐药监测技术方案要求开展耐药监测工作,参考美国临床实验室标准化协会(CLSI)标准对2014—2019年全国1000余家医院上报至全国细菌耐药监测网的非发酵革兰阴性杆菌的临床资料进行总结和分析。结果非发酵革兰阴性杆菌主要分离自呼吸道标本(痰和支气管肺泡灌洗液)、尿、脓液和血,分别占83.6%,6.5%,4.0%和3.6%。铜绿假单胞菌、鲍曼不动杆菌、嗜麦芽窄食单胞菌和洋葱伯克霍尔德菌占分离细菌的比率分别为8.8%,7.3%,2.1%和0.5%。铜绿假单胞菌对多粘菌素B、阿米卡星和庆大霉素的敏感率分别为96.9%~98.2%,89.1%~94.0%和80.1%~86.4%;对哌拉西林和氨曲南的敏感率分别为66.7%~72.8%和58.8%~62.4%;对其余抗菌药物的敏感率维持在70.4%~81.7%。鲍曼不动杆菌对多粘菌素B、阿米卡星和米诺环素的敏感率分别为96.2%~98.0%,51.0%~58.0%和59.4%~63.4%,对其余抗菌药物的敏感率为35.8%~50.0%。嗜麦芽窄食单胞菌对米诺环素、复方磺胺甲口恶唑和左氧氟沙星的敏感率分别为93.0%~95.3%,89.3%~91.4%和85.0%~86.6%,对替卡西林/克拉维酸和氯霉素的敏感率为37.4%~50.3%和46.6%~51.1%。洋葱伯克霍尔德菌对替卡西林/克拉维酸和氯霉素的敏感率分别为18.5%~37.0%和54.4%~62.2%,对其余抗菌药物的敏感率维持在64.7%~86.8%。耐碳青霉烯类铜绿假单胞菌检出率呈下降趋势,而耐碳青霉烯类鲍曼不动杆菌检出率呈现先上升后下降的变化趋势。结论非发酵革兰阴性杆菌对常用抗菌药物的敏感性无明显变化,耐碳青霉烯类铜绿假单胞菌和鲍曼不动杆菌检出率呈下降趋势。     

呼吸重症监护病房肺移植术后患者早期感染病原菌分布与耐药性

 目的 了解呼吸重症监护病房（RICU）肺移植术后患者早期（3个月以内）感染病原菌分布特点及耐药性,为肺移植术后早期感染经验性抗菌药物治疗提供依据。方法 收集2017年9月-2018年9月某医院RICU肺移植术后时间<3个月的患者临床资料及病原学数据,对感染病原菌及其耐药性进行统计分析。结果 共纳入134例患者,分离感染病原菌349株,革兰阴性菌占91.12%,其中≥ 2种菌混合感染病例数占91.04%。前三位病原菌依次为鲍曼不动杆菌、肺炎克雷伯菌、铜绿假单胞菌,分别占29.51%、16.05%、15.47%。标本主要来自痰（81.09%）和支气管肺泡灌洗液（12.89%）。鲍曼不动杆菌对多粘菌素B耐药率为2.91%,对其余药敏测试药物耐药率为56.31%~100.00%。肺炎克雷伯菌对多粘菌素B耐药率为3.57%,对亚胺培南耐药率达69.64%。铜绿假单胞菌对妥布霉素、阿米卡星、庆大霉素、哌拉西林/他唑巴坦、环丙沙星、左氧氟沙星较敏感,耐药率为1.85%~14.81%,未发现对多粘菌素B耐药的菌株。嗜麦芽窄食单胞菌对左氧氟沙星、复方磺胺甲口恶唑、头孢他啶耐药率较低（8.70%~28.26%）。耐甲氧西林金黄色葡萄球菌（MRSA）检出率为95.24%,未检出耐万古霉素、利奈唑胺的金黄色葡萄球菌。结论 RICU肺移植术后患者早期感染病原菌以革兰阴性菌为主,混合感染占比高。不同菌种耐药率存在差异,耐碳青霉烯类鲍曼不动杆菌、肺炎克雷伯检出率较高,需引起临床重视。     

Bacterial and mycotic otological infections in Singapore.

This paper describes a microbiological study of 84 young adult men with clinical otitic infections. Gram-negative aerobic bacilli were frequently isolated from these patients diagnosed as having otitis externa or chronic suppurative otitis media, of which Pseudomonas species predominated. Staphylococcus aureus, S. epidermidis and aerobic Corynebacterium species (diphtheroids) were also found. About 40% of ear infections were attributed to otomycoses, chiefly from Aspergillus species and Candida parapsilosis. Antimicrobial susceptibility testing of the bacterial isolates revealed that Pseudomonas species were generally resistant to antibiotics commonly employed in general practice: ampicillin, erythromycin, co-trimoxazole, tetracycline and cephaloridine. However, polymyxin B, gentamicin and neomycin were active against some Pseudomonas isolates. Other Gram-negative bacilli were also mainly sensitive to gentamicin, neomycin as well as co-trimoxazole. Disc diffusion and minimum inhibitory concentration studies demonstrated good activity of ceftazidime, cefoperazone, tobramycin and carbenicillin against strains of Pseudomonas species and other Gram-negative rods. Cefotaxime and cefoxitin were active against Gram-negative bacilli other than Pseudomonas species. Beta-lactamase production did not appear to be the main mechanism of resistance in these community-acquired Gram-negative bacillary isolates. The antimicrobial therapy of otological infections is reviewed.     

Prophylactic and therapeutic vaccine against Pseudomonas aeruginosa keratitis using bacterial membrane vesicles

PurposePseudomonas aeruginosa (P. aeruginosa) infection is one of the major causes of keratitis. However, effective prophylactic and therapeutic vaccines against P. aeruginosa keratitis have yet to be developed. In this study, we explored the use of P. aeruginosa membrane vesicles (MVs) as a prophylactic vaccine as well as the use of immune sera derived from P. aeruginosa MV-immunized animals as a treatment for P. aeruginosa corneal infections in C57BL/6 mice.MethodsC57BL/6 mice were intramuscularly immunized with P. aeruginosa MVs; the mouse corneas were then scarified and topically infected with several P. aeruginosa strains, followed by determination of corneal clinical score and corneal bacterial load. Next, immune sera derived from P. aeruginosa MV-immunized ICR mice were administered intraperitoneally to naïve C57BL/6 mice, followed by topical P. aeruginosa challenge. Finally, the immune sera were also used as a topical treatment in the mice with established P. aeruginosa corneal infections.ResultsP. aeruginosa-specific IgG and IgA antibodies induced by intramuscular immunization were detected not only in the sera but also in the eye-wash solution. Both active and passive immunization significantly inhibited P. aeruginosa corneal infection. Finally, topical treatment with immune sera in the mice with established P. aeruginosa corneal infections notably decreased the corneal clinical score and corneal bacterial load.ConclusionsP. aeruginosa keratitis can be attenuated by vaccination of P. aeruginosa MVs and topical application of P. aeruginosa MV-specific immune sera.     

Bacterial and mycotic otological infections in Singapore

This paper describes a microbiological study of 84 young adult men with clinical otitic infections. Gram-negative aerobic bacilli were frequently isolated from these patients diagnosed as having otitis externa or chronic suppurative otitis media, of which Pseudomonas species predominated. Staphylococcus aureus, S. epidermidis and aerobic Corynebacterium species (diphtheroids) were also found. About 40% of ear infections were attributed to otomycoses, chiefly from Aspergillus species and Candida parapsilosis. Antimicrobial susceptibility testing of the bacterial isolates revealed that Pseudomonas species were generally resistant to antibiotics commonly employed in general practice: ampicillin, erythromycin, co-trimoxazole, tetracycline and cephaloridine. However, polymyxin B, gentamicin and neomycin were active against some Pseudomonas isolates. Other Gram-negative bacilli were also mainly sensitive to gentamicin, neomycin as well as co-trimoxazole. Disc diffusion and minimum inhibitory concentration studies demonstrated good activity of ceftazidime, cefoperazone, tobramycin and carbenicillin against strains of Pseudomonas species and other Gram-negative rods. Cefotaxime and cefoxitin were active against Gram-negative bacilli other than Pseudomonas species. Beta-lactamase production did not appear to be the main mechanism of resistance in these community-acquired Gram-negative bacillary isolates. The antimicrobial therapy of otological infections is reviewed.     

河南省某医院耐碳青霉烯类革兰阴性杆菌的临床分布及耐药谱

目的了解耐碳青霉烯类革兰阴性杆菌(CR-GNB)的临床分布及其耐药特征,为指导临床抗菌药物的合理使用提供依据。方法收集2017年1月—2018年10月某院临床分离的CR-GNB,使用WHONET5.6软件进行统计学分析。结果共收集CR-GNB 9 506株,其中耐碳青霉烯类抗生素鲍曼不动杆菌(CRAB)3 879株(40.18%),耐碳青霉烯类抗生素肺炎克雷伯菌(CRKP)3 602株(37.89%),耐碳青霉烯类抗生素铜绿假单胞菌(CRPA)1 322株(13.91%),耐碳青霉烯类抗生素大肠埃希菌(CREC)334株(3.51%)。CR-GNB主要分布在ICU(6 340株,66.69%),其次是呼吸内科(751株,7.90%);以呼吸道标本来源的菌株最多(6 614株,69.58%),其次是血标本(800株,8.42%)。四种主要的CR-GNB均对常见抗菌药物普遍耐药,其中CRPA仅对多粘菌素B、阿米卡星较敏感,敏感率分别为99.39%、74.18%;CRAB、CRKP对替加环素、多粘菌素B、米诺环素较为敏感,敏感率为60.30%～99.66%;CREC对替加环素、多粘菌素B、阿米卡星、米诺环素较为敏感,敏感率为66.49%～99.13%。结论 CR-GNB耐药情况严重,特别是ICU分离株,临床医生应个体化制定更为合理的抗感染治疗方案,加强感染控制措施的落实,减少包括CR-GNB在内的多重耐药菌的产生,并控制其在医院内的传播。     

Nosocomial outbreak of severe Pseudomonas aeruginosa infections in haematological patients

From June to September 1988, an outbreak of Pseudomonas aeruginosa infections in neutropenic patients admitted to the Haematological Wards of Ospedali Riuniti in Bergamo, Italy, was detected. Out of 11 cases of P. aeruginosa infections, 8 were bacteremic. Of these, 7 died within few days of onset (mortality rate: 87.5%). Consequently, possible sources of infection were investigated, and moist areas of the hospital environment were shown to be highly contaminated by P. aeruginosa. A clinical and microbiological follow-up of patients admitted to the Haematological Wards was performed for a 10 month period following the outbreak. Adequate measures for cleaning and disinfection were shown to reduce the frequency of P. aeruginosa hospital infections.     

Prevalence of Pseudomonas aeruginosa pyocin and antibiotic biotypes in four Tehran hospitals

Over a 15‐month period, 340 strains of Pseudomonas aeruginosa were isolated from clinical specimens, i.e. sputum, wound swabs, pus, burns, urine, stool, etc., and the environment, i.e. sink, floor, bed sheets, etc., in four Tehran hospitals. Identification of Pseudomonas aeruginosa was carried out by standard methods. Pyocin typing and subtyping were done using the spotting method of Govan, and using a set of 13 indicator strains. Results of the study showed that the dominant pyocin types were PT10, PT4 and PT3, with frequencies of 30.6%, 21.7% and 8.8%, respectively. The pyocins had a wide spectrum of activity, in contrast to most other bacteriocins known. The dominant pyocin subtypes observed in this study were b, d, a, and c, with frequencies of 18.4%, 14.9%, 12.7%, 9.2%, respectively. Approximately 95.9% of the isolates were typable. 98.8% of the Pseudomonas aeruginosa isolates were resistant to 1 or more antibiotics tested. Antibiotic sensitivity tests were performed using the disc diffusion method, employing Mueller‐Hinton Agar. The following antibiotics were tested: Aztreonam (ATM), Ceftazidime (CAZ), Ceftriaxone (CRO), Imipenem (IMP), Cefoperazone (CFP), Amikacin (AN), Sisomicin (SIS), Polymyxin B (PB), Gentamicin (GM), Tobramycin (NN), Netilmicin (NET), Tetracycline (TE) and Carbenicillin (CB). The highest resistance was observed against tetracycline (98.2%), while no resistance was detected against polymyxin B. Among betalactams, ceftazidime and among aminoglycosides, amikacin showed the greatest activities. Distribution of these isolates from the hospital environments was alarming. The results of these findings were reported to the hospital authorities and a number of preventive and control measurements, including more effective methods of disinfection for all instruments that come into contact with patients, were suggested to reduce the spread of the bacterium.     

全国细菌耐药监测网2021年泌尿外科患者分离细菌耐药监测报告

目的 了解2021年全国泌尿外科患者分离细菌菌种分布及耐药情况。方法 按照全国细菌耐药监测网(CARSS)技术方案,应用WHONET 5.6软件对2021年所有CARSS成员单位上报的泌尿外科患者分离细菌及药敏试验结果数据进行分析。结果 泌尿外科患者共分离菌株232 603株,其中革兰阴性菌166 483株(71.6%),革兰阳性菌66 120株(28.4%)。标本构成中排名前5位的分别为尿、血、伤口分泌物、痰和腹腔积液。分离细菌中革兰阴性菌排名前5位的分别为大肠埃希菌(57.5%)、肺炎克雷伯菌(10.8%)、铜绿假单胞菌(5.8%)、奇异变形杆菌(5.3%)和阴沟肠杆菌(3.4%);分离细菌中革兰阳性菌排名前5位的分别为粪肠球菌(36.2%)、屎肠球菌(14.9%)、表皮葡萄球菌(10.5%)、无乳链球菌(9.5%)和金黄色葡萄球菌(7.3%)。未发现对万古霉素、替考拉宁和利奈唑胺耐药的金黄色葡萄球菌,耐甲氧西林金黄色葡萄球菌对庆大霉素、利福平、左氧氟沙星、复方磺胺甲口恶唑、克林霉素和红霉素的耐药率均高于甲氧西林敏感金黄色葡萄球菌。大肠埃希菌、肺炎克雷伯菌、奇异变形杆菌对亚胺培南(...     

Outbreak of nosocomial urinary tract infections due to Pseudomonas aeruginosa in a paediatric surgical unit associated with tap-water contamination

An outbreak of 14 cases of urinary tract infections by Pseudomonas aeruginosa, including six symptomatic infections, occurred from September to November 1994 in a paediatric surgical unit. During the outbreak, urine samples from patients and multiple samples from the environment of patients were tested for the presence of P. aeruginosa. Bacterial isolates were studied by pulsed field gel electrophoresis. Genotypic analysis showed that most of the isolates from children were different. Multiple P. aeruginosa isolates were also found in the tap water, as the only putative source of contamination. Two of these isolates were identified in two infected patients, indicating possible direct contamination of patients via tap water and this was related to the distal colonization of faucets. Bacteria were eradicated from tap water by replacement of taps. The cluster of cases of P. aeruginosa urinary infection was, therefore, related to multiple contaminations through tap water. These results illustrate an unexpected risk of nosocomial infection and emphasizes the importance of checking tap water to prevent bacterial contamination through handwashing in contaminated water.     

Swimmers and Nonswimmers

? Studies were undertaken between the summers of 1970 and 1974 to determine the effects of swimming on the incidence of external otitis and on the isolation of Pseudomonas aeruginosa from infected outer ears.

The frequency of “earaches” reported by swimmers during a telephone survey conducted during the summer of 1971 was 2.4 times the frequency reported by nonswimmers. Furthermore, the risk of a swimmer acquiring external otitis, determined from reports of outer-ear infections received from physicians during the same period, was approximately five times as great as the risk to nonswimmers.

Swimming also increased the risk of P aeruginosa involvement in otitis externa, and reported infections among swimmers tended to be more severe than infections among nonswimmers.     

Epidemiological characteristics ofPseudomonas aeruginosa strains causing infection in an Italian general hospital

During the 1989 calendar year,P. aeruginosa caused clinical infections in 0.46% of patients admitted to Ospedali Riuniti (a general hospital), Bergamo, Italy. Strains (n=267) ofP. aeruginosa were collected during this period, and epidemiological characteristics were studied. The mean prevalence ofP. aeruginosa infection in inpatients was 1.1% (range 0.06–7.3), whereas outpatients showed a significantly lower prevalence of infection (0.05%). Strains were recovered from inpatients of surgical wards (n=126; 47.2%), and outpatients (n=15; 5.6%). Males were more often affected than females (2.7:1). Infection of the urinary tract was the most common (34.1%).Pseudomonas aeruginosa was also involved in lower respiratory tract infections (18.7%) and septicaemia (17.6%). Four typing methods were performed, i.e. serotyping, antibiotyping, pyocin typing, and restriction endonuclease analysis (REA). Serotypes 0:11 and 0:6 were endemic in the hospital. Some serotypes correlated with specific clinical wards. Pyocin typing was an unreliable epidemiological tool. However, antibiotyping showed the presence of some epidemic clusters, probably related to the antibiotic consumption of the patients. REA suggested the circulation of endemicP. aeruginosa strains in both the obstetrics and neurosurgery wards.     

Reservoire von Pseudomonas aeruginosa auf der Intensivstation

In spite of significant changes in the spectrum of organisms causing nocosomial infections in intensive care units (ICUs), Pseudomonas aeruginosa has held a nearly unchanged position as an important pathogen. Today, the organism is isolated as the second most frequent organism causing ventilator-associated pneumonia, and the third or fourth most frequent pathogen causing septicemia, urinary tract infections, and surgical wound infections. In the past, horizontal transmissions were regarded as the most relevant route of strain acquisition. However, during the last 10 years, a significant proportion of P. aeruginosa isolates were demonstrated to stem from ICU water sites. Studies using molecular typing techniques have shown that up to 50% (in one study 92%) of nosocomial P. aeruginosa acquisitions may result from transmission through tap water. Additional proof of concept of waterborne infection comes from the reports of three recent studies that infection rates may be lowered significantly by eliminating colonized tap water sources or interrupting transmission chains from water sites.     

Epidemiology of Pseudomonas aeruginosa in a tertiary referral teaching hospital

A genotypically indistinguishable strain of Pseudomonas aeruginosa (Australian epidemic strain III: AES III) has previously been found in a proportion of adults with cystic fibrosis (CF) in Tasmania, Australia. The aim of this study was to identify a source of these infections within the major tertiary referral hospital for the State of Tasmania, and to determine if this strain could be isolated from settings other than the CF lung. A total of 120 isolates of P. aeruginosa were collected from clinical and environmental sources within the hospital and from environmental locations in the hospital vicinity. These isolates were genotyped by random amplification of polymorphic DNA (RAPD)–polymerase chain reaction (PCR) and antimicrobial susceptibility testing was performed using the Clinical and Laboratory Standards Institute method. Confirmation of similar genotypes identified by RAPD–PCR was performed using pulsed-field gel electrophoresis with restriction enzyme SpeI. AES III was not recovered from any source other than the respiratory secretions of CF patients. P. aeruginosa in the non-CF settings was found to be panmictic, and no cross-infection or acquisition of hospital environment strains by patients was observed.     

全国细菌耐药监测网2021年肾内科患者分离细菌耐药监测报告

目的 了解全国肾内科住院患者常见病原菌分布及耐药性。方法 对2021年全国细菌耐药监测网(CARSS)成员单位上报的所有肾内科住院患者分离菌及其耐药性进行分析。结果 肾内科住院患者共分离细菌122 203株,主要来源于尿、痰及血标本,占比分别为49.2%、16.7%和13.4%,其中,革兰阴性菌共81 994株(67.1%),革兰阳性菌共40 209株(32.9%)。最常见的前5位病原菌分别为大肠埃希菌(39 914株,32.7%)、肺炎克雷伯菌(12 695株,10.4%)、金黄色葡萄球菌(11 977株,9.8%)、铜绿假单胞菌(6 583株,5.4%)及屎肠球菌(5 821株,4.8%)。头孢曲松耐药的大肠埃希菌、肺炎克雷伯菌检出率分别为47.2%(15 704/33 272)、30.7%(3 091/10 070);耐碳青霉烯类的大肠埃希菌、肺炎克雷伯菌和阴沟肠杆菌检出率分别为1.0%(388/38 813)、8.2%(1 000/12 206)和4.8%(135/2 813)。鲍曼不动杆菌对亚胺培南、美罗培南、多黏菌素和替加环素的耐药率分别为27.6%(972/3 523)、...     

Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa isolation from pharyngeal swab cultures among the Japanese elderly at admission to a geriatric hospital

The isolation rate of Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa from pharyngeal swab cultures in the Japanese elderly was studied at admission to a geriatric hospital which had long-term care units. The subjects were 233 consecutive patients who were admitted to K Hospital in the time period April 1994 to March 1996. The isolation rate of MRSA and of Pseudomonas aeruginosa was 10.3% and 8.2% respectively. The proportions of the patients with severely to moderately limited Activities of Daily Living (ADL) (ADL score = 0–1) (P < 0.01), those with fever (P < ;0.01), those with CRP positive (P = 0.04) and those with hypoalbuminemia (serum albumin<3.5 g/dl) (P < 0.01) were higher in the MRSA positive patients than in the negative patients while the proportion of the patients with fever was higher in the Pseudomonas aeruginosa positive patients than in the negative patients (P < 0.02). In the multiple logistic regression analysis, the limitation of ADL (ADL score 0–1 vs 2–3, OR = 1.54, 95% CI = 1.02–2.33) and fever (with vs without, OR = 1.77, 95% CI = 1.18–2.66) remained as risk factors for the isolation of MRSA while only fever (with vs without, OR = 1.67, 95% CI = 1.11–2.53) remained as a risk factor for the isolation of Pseudomonas aeruginosa.     

Plasmid-Mediated Biodegradation of the Anionic Surfactant Sodium Dodecyl Sulphate,by <Emphasis Type="Italic">Pseudomonas aeruginosa</Emphasis> S7

Sodium dodecyl sulphate (SDS), an anionic surfactant, has been used extensively due to its low cost and excellent foaming properties. Fifteen different bacterial isolates capable of degrading SDS were isolated from detergent contaminated soil by enrichment culture technique and the degradation efficiency was assessed by Methylene Blue Active Substances (MBAS) assay. The most efficient SDS degrading isolate was selected and identified as Pseudomonas aeruginosa S7. The selected isolate was found to harbor a single 6-kb plasmid. Acridine orange, ethidium bromide, SDS and elevated temperatures of incubation failed to cure the plasmid. The cured derivatives of SDS degrading Pseudomonas aeruginosa were obtained only when ethidium bromide and elevated temperature (40°C) were used together. Transformation of E. coli DH5α with plasmid isolated from S7 resulted in subsequent growth of the transformants on minimal salt media with SDS (0.1%) as the sole source of carbon. The SDS degradation ability of S7 and the transformant was found to be similar as assessed by Methylene Blue Active Substance Assay. The antibiotic resistance profiles of S7, competent DH5α and transformant were analyzed and it was noted that the transfer of antibiotic resistance correlated with the transfer of plasmid as well as SDS degrading property.     

Protection of mice against P. aeruginosa infections by large-scale affinity-purified human IgG specific to P. aeruginosa outer membrane proteins

In order to develop an effective means to treat Pseudomonas aeruginosa infections, we designed a large-scale process for purification of human IgG specific to P. aeruginosa outer membrane proteins (Oprs) from normal human sera. The process we developed includes affinity column chromatography using P. aeruginosa Oprs as ligands, protein A column chromatography and ultrafiltration, which enriched P. aeruginosa Oprs-specific IgG antibody by 500-fold. The purified anti-Oprs IgG was specific to the Oprs as confirmed by an ELISA competition assay and retained opsonophagocytic-killing capacity. In vivo protective efficacy of anti-Oprs IgG was evaluated by passive protection assays in mice where the 50% protective dose of anti-Oprs IgG against P. aeruginosa infections was 41 μg/kg, which was 20 times lower than that of normal serum IgG. When administered to mice 3 h after bacterial challenge, only anti-Oprs IgG afforded protection. These data demonstrate the feasibility of use of the purification process in producing functionally active target-specific human antibodies for clinical use and provide a rationale for use of anti-Oprs IgG as a valuable adjunct to treat P. aeruginosa infections.     

Hansenula anomala outbreak at a surgical intensive care unit: A search for risk factors

During a 5-month period, Hansenula anomala (H. anomala), an opportunistic fungus, caused an outbreak of infections in eight adult patients treated at a surgical intensive care unit (ICU). The source of the infections and route of transmission could not be identified. A case–control study included 32 patients treated simultaneously at the surgical ICU. Univariate analysis pointed to the following significant risk factors: blood alkalosis, reduced urea, duration of hospitalization, bacteremia and colonization with Pseudomonas aeruginosa, and an APACHE II score >17 (during bacteremia or fungemia). The stepwise logistic regression multivariate analysis showed only the duration of blood alkalosis to be significant in case patients.