Susceptibilities of coagulase-negative staphylococci to aminoglycosides antibiotics as compared by early bactericidy assays

Twenty four strains of coagulase-negative staphylococci from clinically significant blood cultures were separated in four groups on the basis of oxacillin susceptibility and phenotype of resistance to aminoglycoside antibiotics. Susceptibility testing included disk diffusion testing, M.I.C. and M.B.C. determinations and finally, measurements, at sequential times (from 0 to 6 hours), of the bactericidal effect of aminoglycosides alone or combined with oxacillin or vancomycin. Aminoglycosides clinical use (gentamicin, netilmicin, tobramycin and amikacin) exhibited an efficient early bactericidy over the sensitive strains to any tested aminoglycosides and to oxacillin (group 1, 13 strains). When strains having a phenotype of resistance to kanamycin and neomycin (group 2, 4 strains) or kanamycin and tobramycin (group 3, 2 strains) were considered, amikacin inefficiency was assessed by time-killing assay even though disk diffusion testing as well as M.I.C. and M.B.C. determinations failed to demonstrate it. In the same way, only bactericidy measurements indicated the lack of activity of amikacin or netilmicin over strains exhibiting a phenotype of resistance to gentamicin plus kanamycin and tobramycin (group 4, 5 strains). Netilmicin appeared as the most active aminoglycoside over the strains studied. Crude results of disk diffusion testing might appear as an oversimplification, especially when coagulase-negative staphylococci are considered; the early-bactericidy assay findings were stressing for the need of interpreting the results of antibiotic testing on the ground of resistance mechanisms.     

Aminoglycoside-resistant enterococci.

Thirty-four recent clinical isolates of Streptococcus faecalis were tested for sensitivity to amoxycillin, benzylpenicillin, streptomycin, kanamycin, gentamicin, tobramycin, and amikacin. Amoxycillin was two- to four-fold more active than benzylpenicillin and all strains were inhibited by low concentrations of the penicillins. The aminoglycosides were less active against the enterococci than were the penicillins and a significant number of strains were insensitive or relatively insensitive to one or more of the aminoglycosides. Thus, eight (23%) strains showed a high level of resistance to streptomycin and kanamycin (MIC greater 5000 microng/ml) but were sensitive to gentamicin, tobramycin, and amikacin. In addition, two strains of Strep. faecalis, isolated at different hospitals from patients who had received topical gentamicin therapy, were relatively resistant to gentamicin (MIC250 to 500 microng/ml) and were less sensitive also to the other aminoglycosides. Bactericidal synergy was demonstrated by amoxycillin/aminoglycoside combinations against the enterococci, provided that the test strain of Strep. faecalis was sensitive to the aminoglycoside in the combination. An exception to this was the combination of amoxycillin plus amikacin which was not synergistic against kanamycin-resistant strains of Strep. faecalis although these organisms were sensitive to amikacin in the growth inhibition tests. The gentamicin-resistant strains showed variable responses to amoxycillin/aminoglycoside combinations in tests for bactericidal synergy and were generally less sensitive than typical strains of Strep. faecalis.     

Resistance of gram-negative bacilli and staphylococci from blood cultures to aminoglycoside antibiotics. Comparison of 3 in vitro investigations from Austria 1982-1988

A total of 790 blood culture isolates was collected during 3 study periods in 1982/83, 1984/85 and 1987/88. Staphylococci were the most frequent bacteria in the first two periods (56.5% and 63%, respectively). During the last period, E. coli was the most frequent of all species (27%). Differences in the distribution of bacteria between the laboratories were considerable. In one laboratory in Vienna, coagulase-negative staphylococci dominated in all 3 study periods (32%, 33% and 47%). Susceptibility against gentamicin, tobramycin and netilmicin (MIC less than or equal to 4 mg/l), as well as against amikacin (MIC less than or equal to 8 mg/l) were determined by a microdilution method. The resistance rates against gentamicin (G) were 25%, 21% and 25%, against tobramycin (T) 27%, 19% and 25%, against netilmicin (N) 6%, 4% and 19%, and against amikacin (A), 5%, 2% and 19%. Most resistant strains were staphylococci (G 26%-41%, T 26%-46%, N 3%-31%, A 3%-36%), whereas gram-negative bacilli were more susceptible (G 12%-14%, T 7%-11%, N 7%-9%, A 1%-7.5%). The increase of resistance against netilmicin and amikacin in staphylococci was most striking. Nearly all those strain could be attributed to one laboratory in Vienna. Most of them were coagulase-negative staphylococci. In the first study period, the most frequent pattern was resistance against gentamicin and tobramycin, whereas in the last period resistance to all 4 aminoglycosides dominated. The study demonstrates considerable local differences in antibiotic resistance. Monitoring of antibiotic resistance in collaborative studies using standardized methods should be a valuable tool in planning strategies for controlling an epidemic spread of resistance.     

Comparative activity of habekacin and 4 other aminoglycosides against gram-negative bacilli. Evolution of resistance

The activity of 5 aminoglycosides compounds (habekacin, amikacin, gentamicin, netilmicin and tobramycin) was studied by an agar dilution method, against 235 strains of Enterobacteriaceae and 146 other Gram negative bacilli. 79 to 98% of susceptible strains were observed, according to the aminoglycoside compound. Habekacin and amikacin were the most effective, specially against the more frequently resistant bacteria: Enterobacter, Serratia, Hafnia, Acinetobacter, Pseudomonas aeruginosa. In comparison with a previous study, no evolution was observed in the resistance to aminoglycosides.     

Comparative effects of netilmicin and 4 other aminoglycosides on 1028 bacterial strains isolated in a hospital milieu

The activity of netilmicin and four other aminoglycosides was studied by a diffusion method against 1 028 bacterial strains isolated in hospital. Nearly all the strains of Gram-negative bacilli were susceptible to amikacin; with netilmicin, tobramycin, gentamicin and dibekacin the percentages of susceptible strains were smaller, without any statistically significant differences between them. Amikacin and netilmicin were the most effective compounds against staphylococci. Netilmicin seemed to be the most effective compound, in vitro, against streptococci. The MIC of gentamicin and netilmicin of 224 strains showed the superior activity of netilmicin against K. pneumoniae, Proteus, P. aeruginosa and S. aureus.     

Three-year survey of amikacin use and aminoglycoside resistance in a general hospital in Belgium

The aim of the study was to evaluate the effect of intensive use of amikacin on the resistance levels to amikacin, gentamicin, tobramycin, netilmicin and dibekacin. The base-line resistance in the preamikacin phase (three months of amikacin use less than 1 %; 676 isolates) was 1.0 % for amikacin, 11.4 % for gentamicin, 8.0 % tobramycin, 6.2 % for netilmicin and 8.3 % for dibekacin. During the amikacin phase (36 months of average amikacin use of 89 %; 6048 isolates) there was no significant change in aminoglycoside resistance except for dibekacin (from 8.3 % to 10.9 %, 0.05>p>0.02). Isolated amikacin resistance was not observed.     

Antimicrobial resistance among gram-negative bacilli to newer aminoglycosides and beta-lactams.

Two hundred and fifty nine i.e. 30.72% of 843 strains of gram negative bacilli were resistant to gentamicin. When tested against newer aminoglycosides, 48.9% were resistant to tobramycin, 4.1% to amikacin and 20.5% to netilmicin. Marked cross-resistance between gentamicin and tobramycin was seen. All these strains were resistant to ampicillin, amoxycillin and co- trimoxazole. However, a high level of antimicrobial activity was seen with third generation cephalosporins, cefotaxime and ceftriaxone. Minimum inhibitory concentrations of gentamicin and tobramycin were of significant level. Gentamicin resistance could be transferred directly in 20 of 45 strains of S. typhimurium where conjugation experiments were done.     

88株嗜麦芽窄食单孢菌氨基糖苷类耐药性及其修饰酶基因分析

目的明确2005年8月至2007年7月临床分离的88株嗜麦芽窄食单孢菌对氨基糖苷类抗生素的耐药性及其修饰酶基因的存在状况。方法用Kirby—Bauer（K-B）药敏试验分析88株嗜麦芽窄食单孢菌对3种常用氨基糖苷类抗生素阿米卡星、庆大霉素、妥布霉素的敏感性，再用聚合酶链反应（PeR）法分别扩增常见的8种氨基糖苷修饰酶基因。结果这88株嗜麦芽窄食单孢菌同时对3种氨基糖苷类抗生素都耐药的有19株．占21．6％（19／88）；同时对这3种抗生素都敏感的有12株，占13．6％（12／88）；对阿米卡星，庆大霉素和妥布霉素的耐药率分别为22％，69．3％和58％，敏感率分别为70％，22．7％和23．9％。氨基糖苷修饰酶基因aac（3）-Ⅰ和ant（4′）-Ⅱ未检测到；其余6种基因中，aac（3）-Ⅱ，ant（2′′）-Ⅰ，aae（6′）-I，aae（3）-Ⅲ，aae（3）-Ⅳ和aac（6′）-Ⅱ）的检出率分别是2．3％，5．7％，8％，11．4％，11．4％和12．5％。结论临床分离的嗜麦芽窄食单孢菌对氨基糖苷类修饰酶携带率不是很高，但氨基糖苷类抗生素耐药情况却很严重。     

Detection of aminoglycoside-penicillin synergy againstEnterococcus faecium using high-content aminoglycoside disks

Thirty-sevenEnterococcus faecium strains were screened for high-level aminoglycoside resistance with an agar diffusion test using high-content aminoglycoside disks (300 g of streptomycin and 120 g of gentamicin, tobramycin, kanamycin or amikacin). The inhibition zones obtained were correlated with results of time-kill penicillin-aminoglycoside synergy studies. An 11 mm breakpoint differentiated strains susceptible or resistant to the synergy of streptomycin plus penicillin. Irrespective of the inhibition zones obtained with tobramycin and kanamycin disks,Enterococcus faecium strains never showed synergy with penicillin in combination with these aminoglycosides. Penicillin-amikacin synergy cannot be predicted by the amikacin disks. Nevertheless, even though kanamycin disks do not predict penicillin-kanamycin synergy, they can be used to predict penicillinamikacin synergy. In summary, high-content streptomycin, gentamicin and kanamycin disks can be used to predict the susceptibility ofEnterococcus faecium strains to the synergistic combination of penicillin plus one of the aminoglycosides (streptomycin, gentamicin or amikacin, respectively).     

Antimicrobial resistance in coagulase-negative staphylococci

Patterns of resistance to antimicrobial agents were studied in 193 strains of coagulase-negative staphylococci isolated from hospital patients. Strains isolated from patients with malignant disease were significantly more often resistant to sulphonamide, trimethoprim, gentamicin and methicillin than were strains from other sources. Susceptibility to various beta-lactam antibiotics and aminoglycosides was investigated in members of the two most frequent species: Staphylococcus epidermidis and S. haemolyticus. S. haemolyticus strains were not only more often resistant to methicillin than S. epidermidis strains (respectively 81% and 17%) but they were more highly resistant (mean MICs respectively 85 and 19 mg/L). Methicillin-resistant S. haemolyticus strains were highly resistant to nine other beta-lactam antibiotics, whereas methicillin-resistant S. epidermidis strains showed both lower levels and a narrower spectrum of cross-resistance. Resistance to methicillin in members of both species was "heterogeneous", i.e., only a minority of cells in a culture showed significant resistance. Almost all gentamicin-resistant strains were sensitive to netilmicin and amikacin; rifampicin, vancomycin and teicoplanin were also highly active in vitro.     

Staphylococcus aureus nosocomial infections in an intensive care milieu (1985-1989) in Tunis]

221 strains of Staphylococcus aureus oxacillin resistant (MetiR) caused nosocomial infections were isolated from 1985 to 1989 in a medical intensive care unit. The survey of susceptibility to antibiotics was established according to the computerized data of disk susceptibility test. The resistance phenotypes to beta-lactams, aminoglycosides and macrolides were established for epidemiological study. S. aureus infections were mainly bacteraemia (31%) and peritonitis (12%). These isolates were resistant to oxacillin with a high level (mean MIC 386 micrograms/ml). Their resistance phenotypes were MLSBc (constitutive resistance to macrolides, lincosamine and streptogramines B) in 53% and S + KGT (resistance to streptomycin, kanamycin, gentamicin and tobramycin) in 61%. All the isolates were susceptible to pristinamycin and vancomycin (MIC 0.1 and 2 micrograms/ml). These phenotypes related to the spread of multiply drug resistant strains were responsible of nosocomial outbreaks. Strains with the same pattern of resistance were isolated among the medical staff and in the environment. Infection control measures allowed to stop these outbreaks.     

Aminoglycoside resistance in Pseudomonas aeruginosa isolated from cystic fibrosis patients

The authors studied 30 gentamicin-resistant and 17 gentamicin-sensitive strains of Pseudomonas aeruginosa isolated from respiratory cultures of patients with cystic fibrosis from five United States cities for the presence of plasmids, cross-resistance to other aminoglycosides, and the production of aminoglycoside-modifying enzymes. Four of 30 resistant strains and 3 of 17 sensitive strains contained one or more plasmids. Aminoglycoside cross-resistance to tobramycin, amikacin, and netilmicin was seen in 21 of 30 gentamicin-resistant strains. Seven strains that had low-level gentamicin resistance (minimum inhibitory concentrations [MIC] = 8-32 micrograms/mL) were sensitive to one or more of the other three aminoglycosides. Two strains with high-level gentamicin resistance (MIC greater than or equal to 128 micrograms/mL) were sensitive to amikacin. These two strains, each containing three plasmids, were the only isolates of nine tested that produced an aminoglycoside-modifying enzyme with activity against gentamicin. None of the plasmids was transferable by conjugation. Four strains, three of which contained one or more plasmids, produced an aminoglycoside 3'-0-phosphotransferase II. The authors propose that the mechanism of gentamicin resistance in P. aeruginosa from patients with cystic fibrosis is not commonly plasmid-mediated and likely is due to membrane impermeability to aminoglycosides.     

Evaluation of the AutoMicrobic system for susceptibility testing of aminoglycosides and gram-negative bacilli.

The AutoMicrobic system (AMS; Vitek Systems, Inc., Hazelwood, Mo.) was compared with a reference broth microdilution MIC method to determine the accuracy and reproducibility of aminoglycoside susceptibility testing of gram-negative bacilli. Stock clinical isolates (n = 176) which demonstrated resistance to at least one aminoglycoside, extended-spectrum penicillin, or broad-spectrum cephalosporin (or a combination) were selected for this study. Isolates with moderate susceptibility to the aminoglycosides were also included. Of these isolates, 116 were either resistant or moderately susceptible to one or more of amikacin, gentamicin, netilmicin, and tobramycin. When AMS MIC results for 704 antimicrobial agent-organism combinations were compared with parallel microdilution MIC results, exact agreement (AMS MIC = reference MIC) rates were: amikacin, 71.6%; gentamicin, 71.6%; netilmicin, 83.0%; and tobramycin, 69.3%. Agreement rates within +/- 1 log2 dilution were: amikacin, 96.0%; gentamicin, 93.8%; netilmicin, 97.2%; and tobramycin, 96.0%. When National Committee for Clinical Laboratory Standards criteria were used to qualitatively evaluate performance, the overall agreement rates were: amikacin, 100.0%; gentamicin, 99.4%; netilmicin, 98.9%; and tobramycin, 99.4%. There were only four very major discrepancies, which represented 0.6% of the tests performed, and there were no major discrepancies. The percentages of minor discrepancies were: amikacin, 9.6%; gentamicin, 14.2%; netilmicin, 11.9%; and tobramycin, 10.8%. Of the overall average of 11.6% minor discrepancies, 9.7% occurred even though the AMS MIC was within +/- 1 log2 dilution of the reference MIC. The intralaboratory reproducibility ranged from 93.3 to 100% for the four drugs examined. With this challenge group of gram-negative bacilli, the AMS generated aminoglycoside MIC results that were comparable to those obtained by a reference broth microdilution method.     

Adaptive resistance to aminoglycoside antibiotics in Pseudomonas aeruginosa

Aminoglycoside-resistant variants of Pseudomonas aeruginosa strain PAO1 were readily selected by culturing the organism in medium containing increasing concentrations of gentamicin, tobramycin or amikacin until the strains were growing in a concentration of drug 128-fold greater than the minimal inhibitory concentration for the sensitive parent strain. These resistant strains exhibited characteristics previously associated with the impermeability type of resistance mechanism, i.e., they grew more slowly than the parent strain, the resistance was unstable in the absence of the antibiotic, and adaptation to one of the antibiotics conferred cross-resistance to other aminoglycosides. The adapted strains grew, with minimal morphological alterations, in concentrations of the various aminoglycosides that normally produced cell envelope damage, misshapen and filamentous cell formation, and cell lysis in the sensitive strain. Neither protein H1 nor phospholipid alterations appear to play a significant role in adaptive resistance to aminoglycoside antibiotics in this model system. The acquisition of adaptive resistance to the aminoglycoside antibiotics did not confer resistance to polymyxin B, another cationic antibiotic which is thought to share binding sites within the outer membrane with the aminoglycosides.     

High-content aminoglycoside disks for determining aminoglycoside-penicillin synergy against Enterococcus faecalis.

We investigated the use of high-content aminoglycoside disks for determining Enterococcus faecalis susceptibility to aminoglycoside-penicillin synergy. The susceptibility of the organisms to synergy was established by 24-h time-kill studies performed with streptomycin, kanamycin, amikacin, gentamicin, and tobramycin, alone and in combination with penicillin. A total of 20 isolates that were susceptible to all drug combinations and 20 strains that were resistant to each aminoglycoside-penicillin combination were selected for testing against high-content disks. Disk-agar diffusion was performed on Mueller-Hinton agar, with and without 5% sheep blood, by using disks that contained either 300 or 2,000 micrograms of streptomycin and either 120 or 2,000 micrograms of kanamycin, amikacin, tobramycin, or gentamicin. Zone size results obtained for each aminoglycoside, except amikacin, could be used to differentiate between synergy-susceptible and -resistant isolates. No overlap occurred between the zone sizes of susceptible and resistant strains. Susceptibility to amikacin-penicillin synergy could reliably be tested with kanamycin, but not amikacin, disks. When the disks containing 120 micrograms were tested, a narrow zone size range of 6 to 7 mm could be used to identify all resistant strains. In contrast, when the disks containing 2,000 micrograms were used, the zone size ranges for resistant isolates varied widely with the aminoglycoside being tested. The presence of blood in the medium did not appreciably affect the disk test results. To detect resistance to every aminoglycoside-penicillin combination that may be considered for therapy, E. faecalis isolates need to be tested against a maximum of three different high-content disks (i.e., streptomycin, gentamicin, kanamycin). The disk-agar diffusion test performed with high-content aminoglycoside disks can provide laboratories with a convenient and reliable method for detecting E. faecalis isolates that are resistant to aminoglycoside-penicillin synergy.     

In vitro and in vivo synergy between ceftriaxone and aminoglycosides againstPseudomonas aeruginosa

The antibacterial interaction between ceftriaxone and the aminoglycosides tobramycin, gentamicin and amikacin againstPseudomonas aeruginosa was investigated in vitro and in experimental systemic infections of the mouse. In vitro synergy was observed in 70% of the strains with tobramycin, 67.5% with gentamicin, and 77.5% with amikacin. Synergistic bactericidal activity was demonstrated with all three aminoglycosides in combination with ceftriaxone. In line with these in vitro results, synergism against most isolates also occurred in mice. In leukopenic mice, the addition of ceftriaxone resulted in a more than 2.5-fold reduction of the aminoglycoside dose necessary for antiinfective protection, although ceftriaxone alone was only marginally active against the pathogen used in immunocompromised animals.     

Synergistic activity of aminoglycoside-beta-lactam combinations against Pseudomonas aeruginosa with an unusual aminoglycoside antibiogram

The bactericidal activity of aminoglycosides alone and in combination with various beta-lactams was studied by the time-kill technique against ten Pseudomonas aeruginosa isolates with an unusual antibiogram (amikacin-resistant, gentamicin-resistant, tobramycin-susceptible [A^rG^rT^s]). Previous studies have indicated that A^rG^rT^s isolates are moderately resistant to all aminoglycosides and many are multiply resistant to beta-lactams. Aminoglycoside-beta-lactam combinations showed infrequent synergistic (16%) or enhanced killing (12%) against the A^rG^rT^s isolates. Synergistic activity, when present, was more likely to occur with tobramycin and amikacin than with gentamicin, even though these differences were not statistically significant. Antibiotic resistance patterns were not predictive of synergy or enhanced killing. Systemic infections produced by A^rG^rT^s isolates that are multiply resistant to the beta-lactams may not respond to combination therapy with an aminoglycoside and beta-lactam. Alternative treatment with polymyxin B or a quinolone may be required for these infections.     

The optimal aminoglycoside and its dosage for the treatment of severe Enterococcus faecalis infection. An experimental study in the rabbit endocarditis model

Aminoglycosides are recommended for the treatment of Enterococcus faecalis infections, especially in severe and bacteremic infection. However, the optimal aminoglycoside or the optimal dosage remains uncertain. This study aimed to compare the activity of four aminoglycosides against E. faecalis (gentamicin, netilmicin, tobramycin, and amikacin) and two dosages of gentamicin. One clinical strain of E. faecalis was used to induce aortic endocarditis in the study rabbits. Each aminoglycoside was infused daily over 3?days with a computer-regulated flow simulating human pharmacokinetics of 15?mg/kg/day for amikacin, 6?mg/kg/day for netilmicin, and 3?mg/kg/day for gentamicin and tobramycin. Additionally, two dosages of gentamicin (simulating 3 or 6?mg/kg/day) were compared over 1 or 3?days of treatment. The in vivo efficacy was assessed according to the bacterial count in vegetations, in comparison with a control group. Of the four aminoglycosides tested, only gentamicin and netilmicin showed significant antibacterial efficacy after 3?days of treatment. After only 1?day of treatment, the high dosage of gentamicin (6?mg/kg/day) was more effective than the standard dosage (3?mg/kg/day). Among the tested aminoglycosides, gentamicin showed the best efficacy, with the best results after 24 h of treatment for the highest dosage.     

Aminoglycoside resistance among blood culture isolates

A total of 633 blood culture isolates were collected from 1981 to 1982 from seven major Finnish hospitals, including all university central hospitals. Susceptibility of the strains to gentamicin, tobramycin, amikacin, and netilmicin was determined by the Sensititre microtiter procedure. Resistance against any of these agents occurred in 1.3 to 6.5% of all strains studied. In the Turku University Central Hospital, an increased number of tobramycin- and gentamicin-resistant Staphylococcus epidermidis were found; the frequency of strains resistant to tobramycin was 57% and to gentamicin was 29% versus frequencies of 16 and 18%, respectively, which were observed in the other hospitals. An explanation for this might be a change in the use of aminoglycosides in the Turku University Central Hospital; within 3 years, 1979 to 1981, the consumption of tobramycin and amikacin had increased 330 and 290%, respectively, whereas the use of gentamicin had decreased to 24% of that in the beginning of the period. Resistance against tobramycin was mediated by enzymes APH(2")-AAC(6') and ANT(4').     

醋酸钙-鲍曼不动杆菌复合体的精确鉴定与药敏分析

目的精确鉴定醋酸钙-鲍曼不动杆菌复合体菌株;检测菌株对氨基糖苷类抗生素和碳青霉烯类抗生素的敏感性。方法运用自动化分析仪VITEK 2试卡法对临床分离不动杆菌进行菌种鉴定,对鉴定为醋酸钙-鲍曼不动杆菌复合体的菌株进一步经16S rRNA序列分析确证其准确种属。分别用自动化分析仪VITEK 2和微稀释法测定精确鉴定后的醋酸钙-鲍曼不动杆菌复合体菌株对阿米卡星、庆大霉素、妥布霉素、亚胺培南和厄他培南五种抗生素的敏感性,分析药敏实验结果。结果共进行了232株不动杆菌的VITEK 2鉴定,其中195株鉴定为醋酸钙-鲍曼不动杆菌复合体。对195株醋酸钙-鲍曼不动杆菌复合体菌株进一步用16S rRNA序列分析确证其准确种属,结果显示173株为鲍曼不动杆菌,22株为醋酸钙不动杆菌。对173株鲍曼不动杆菌及22株醋酸钙不动杆菌分别用VITEK 2和微稀释法进行阿米卡星、庆大霉素、妥布霉素、亚胺培南和厄他培南五种抗生素的药敏检测。微稀释法药敏结果显示,受试鲍曼不动杆菌对三种氨基糖苷类抗生素均呈现高水平耐药,而对两种碳青霉烯类抗生素敏感度较高;受试醋酸钙不动杆菌对五种抗生素均呈现较高敏感度。与微稀释法药敏检测结果相比,VITEK 2试卡法药敏结果中受试鲍曼不动杆菌和醋酸钙不动杆菌对各抗生素的药敏检测结果均出现了不同程度的误差,鲍曼不动杆菌药敏检测结果中阿米卡星符合率最低,严重错误率高达34.10%;醋酸钙不动杆菌药敏检测结果中厄他培南符合率最低,重大错误率高达40.91%。结论 VITEK 2在不动杆菌种属鉴定中存在局限性,辅以16S rRNA序列分析,方可精确鉴定醋酸钙-鲍曼不动杆菌复合体。鲍曼不动杆菌对氨基糖苷类抗生素耐药现状严重。用VITEK 2进行鲍曼不动杆菌和醋酸钙不动杆菌对氨基糖苷类和碳青霉烯类的药敏测定时存在不同程度的误差,建议辅以微稀释法。