Orrett F A
Department of Pathology and Microbiology, Faculty of Medical Sciences, University of the West Indies, St. Augustine, Republic of Trinidad and Tobago, West Indies.
Zhonghua Yi Xue Za Zhi (Taipei). 1999 Jul;62(7):438-42.
Proteus bacteria are a well-known cause of urinary tract infections (UTIs). The prevalence of UTIs is high among catheterized patients and those undergoing manipulation of the urinary tract. This study assessed the prevalence of UTIs due to Proteus species, the predisposing factors, complications and extent of antimicrobial resistance at a regional teaching hospital.
Urine samples in sterile containers from inpatients and outpatients were inoculated onto cysteine lactose electrolyte deficient agar and sheep blood agar plates with calibrated (0.001 ml) platinum loops and incubated aerobically at 35 degrees C to 37 degrees C for 18 to 24 hours. A colony count of 10(5) bacteria/ml or more was the criterion for significant bacteriuria. Proteus spp were identified and classified into four groups. Susceptibility testing was performed via the Kirby-Bauer disc diffusion technique on Müeller-Hinton agar using ampicillin (10 micrograms), tetracycline (30 micrograms), nalidixic acid (30 micrograms), gentamicin (10 micrograms), nitrofurantoin (30 micrograms), co-trimoxazole (30 micrograms) and cefuroxime (30 micrograms).
Of 1,397 urine specimens from hospital and community patients, 414 had one or more species of bacteria isolated, of which 74 (17.9%) were Proteus spp. Hospital-acquired UTIs accounted for more than two-thirds (51/74, 68.9%) of Proteus spp isolates, while community-acquired UTIs accounted for approximately one-third (23/74, 31.1%) of all Proteus isolates. The prevalence of Proteus UTIs in males was 34 of 184 (18.5%) and was slightly higher than in females (40/230, 17.4%). P mirabilis was the most frequently isolated Proteus sp (55/74, 74.3%), followed by P vulgaris (9/74. 12.2%), Morganella morganii, (7/74, 9.5%) and Providencia rettgeri (3/74, 4.0%). Forty-nine of 55 (89%) P mirabilis isolates were biotype 2. Catheterization was the most common predisposing factor in 32.4% of hospital-acquired Proteus UTIs. More than 92% of Proteus isolates were sensitive to gentamicin and nalidixic acid, whereas, ampicillin (35%) and tetracycline (18%) were the least effective drugs.
Proteus was isolated from about 18% of patients with significant bacteriuria. Most isolates occurred in hospitalized patients with indwelling urinary catheters and in patients with benign prostatic hypertrophy, diabetes and prostatectomy. Proper catheter care may improve infection control and reduce the morbidity of UTIs associated with Proteus spp.
变形杆菌是尿路感染（UTIs）的常见病因。导尿患者和接受尿路操作的患者中UTIs的患病率较高。本研究评估了某地区教学医院中变形杆菌属所致UTIs的患病率、易感因素、并发症及抗菌药物耐药程度。
用校准过的（0.001 ml）白金接种环将住院患者和门诊患者无菌容器中的尿液样本接种到半胱氨酸乳糖电解质缺乏琼脂和羊血琼脂平板上，于35℃至37℃需氧培养18至24小时。每毫升尿液中细菌菌落数达到10⁵个或更多为有意义菌尿的标准。对变形杆菌进行鉴定并分为四组。采用 Kirby-Bauer 纸片扩散法在 Müller-Hinton 琼脂上进行药敏试验，使用的抗菌药物有氨苄西林（10微克）、四环素（30微克）、萘啶酸（30微克）、庆大霉素（10微克）、呋喃妥因（30微克）、复方新诺明（30微克）和头孢呋辛（30微克）。
在来自医院和社区患者的1397份尿液标本中，414份分离出一种或多种细菌，其中74份（17.9%）为变形杆菌属。医院获得性UTIs占变形杆菌属分离株的三分之二以上（51/74，68.9%），而社区获得性UTIs约占所有变形杆菌分离株的三分之一（23/74，31.1%）。男性变形杆菌UTIs的患病率为184例中的34例（18.5%），略高于女性（40/230，17.4%）。奇异变形杆菌是最常分离出的变形杆菌菌种（55/74，74.3%），其次是普通变形杆菌（9/74，12.2%）、摩根摩根菌（7/74，9.5%）和雷氏普罗威登斯菌（3/74，4.0%）。55株奇异变形杆菌分离株中有49株（89%）为生物型2。导尿是32.4%的医院获得性变形杆菌UTIs最常见的易感因素。超过92%的变形杆菌分离株对庆大霉素和萘啶酸敏感，而氨苄西林（35%）和四环素（18%）是最无效的药物。
约18%有意义菌尿患者分离出变形杆菌。大多数分离株见于留置导尿管的住院患者以及患有良性前列腺增生、糖尿病和前列腺切除术后的患者。妥善的导尿管护理可能改善感染控制并降低与变形杆菌属相关的UTIs发病率。
