Antimicrobial susceptibilities of clinical isolates of Haemophilus influenzae and Moraxella catarrhalis collected during 1999–2000 from 13 countries

Objective   To determine antimicrobial activity against Haemophilus influenzae and Moraxella catarrhalis .
Methods   A central laboratory performed NCCLS susceptibility testing for all isolates and β -lactamase and capsular serotype determinations for H. influenzae .
Results   A total of 2712 H. influenzae and 1079 M. catarrhalis were collected . H. influenzae susceptibilities were >90% for amoxicillin/clavulanate, cefaclor, loracarbef, cefprozil, cefuroxime, ciprofloxacin, azithromycin and clarithromycin and were <80% for trimethoprim/sulfamethoxazole and ampicillin. 19.3% were β -lactamase positive. The most common serotype was type-b (5.6%); 86.1% were nontypeable. M. catarrhalis had MIC₉₀ within therapeutic range for all antimicrobials except ampicillin.
Conclusion   The conclusion of the study is that antimicrobials, except ampicillin and trimethoprim/sulfamethoxazole, remain good empiric choices against H. influenzae and M. catarrhalis .     

In vitro activities of new quinolones against Brucella melitensis isolated in a tertiary-care hospital in Turkey

We have evaluated the in vitro activities of seven fluoroquinolones against 69 strains of Brucella melitensis . According to their minimum inhibitory concentration for 90% growth (MIC₉₀) values, the most active agent was found to be sparfloxacin (MIC₉₀ 0.12 mg/L) followed by levofloxacin, ciprofloxacin, ofloxacin (MIC₉₀ 0.50 mg/L) and grepafloxacin (MIC₉₀ 1 mg/L), gemifloxacin (MIC₉₀ 2 mg/L) and gatifloxacin (MIC₉₀ 4 mg/L).     

Activity of telithromycin against 26 quinolone-resistant pneumococci with known quinolone-resistance mechanisms

NCCLS agar dilution was used to test activity of telithromycin compared to clarithromycin, penicillin G, ciprofloxacin, levofloxacin, sparfloxacin and moxifloxacin against 26 pneumococci with defined quinolone resistance (type II topoisomerase and efflux) mechanisms. Thirteen strains were penicillin susceptible, six intermediate and seven resistant. Clarithromycin resistance ( mef and/or erm ) was seen in eight strains. Ciprofloxacin MICs (mg/L) were 8–64 compared to 1–32 (levofloxacin), 0.5 ≥ 32 (sparfloxacin) and 0.125–4 (moxifloxacin). Telithromycin MIC₅₀ and MIC₉₀ values (mg/L) were 0.016 and 0.25, with only one strain having an MIC of 2 mg/L.     

In vitro activity of tigecycline and occurrence of tetracycline resistance determinants in isolates from patients enrolled in phase 3 clinical trials for community-acquired pneumonia

The in vitro activity of tigecycline was evaluated against baseline pathogens isolated from patients enrolled in phase 3 clinical trials for community-acquired pneumonia conducted in 29 countries worldwide. Tigecycline was active against the most prevalent pathogens, including Streptococcus pneumoniae (MIC₉₀ 0.06 mg/L), Staphylococcus aureus (MIC₉₀ 0.25 mg/L), Haemophilus influenzae (MIC₉₀ 0.5 mg/L) and Klebsiella pneumoniae (MIC₉₀ 1 mg/L). Twelve isolates of S. pneumoniae expressing tet (M) and two isolates of K. pneumoniae producing extended-spectrum β-lactamases isolated during the study were susceptible to tigecycline. The excellent in vitro activity of tigecycline against these clinical isolates confirmed its potential utility against pathogens associated with community-acquired pneumonia.     

Comparative in vitro activities of five quinolone antibiotics, including gemifloxacin, against clinical isolates

The in vitro activities of ciprofloxacin, ofloxacin, norfloxacin, levofloxacin and gemifloxacin against 343 clinical isolates were compared. Gemifloxacin showed the greatest activity, with MIC₉₀ values as low as 0.03–0.25 mg/L against Streptococcus pneumoniae , Haemophilus influenzae , Moraxella catarrhalis , methicillin-susceptible Staphylococcus aureus and Klebsiella pneumoniae , while methicillin-resistant Staphylococcus aureus , Enterococcus spp., Pseudomonas spp., Acinetobacter spp., Escherichia coli and Enterobacter spp. strains exhibited low rates of susceptibility to all five fluoroquinolones.     

Comparative activity of linezolid against staphylococci and enterococci isolated in Italy

The activity of linezolid, a new oxazolidinone, was tested against 862 Gram-positive cocci isolated in Italy and compared with the activities of 12 antibiotics. Overall, MIC₉₀s for linezolid (2–4 mg/L) indicated an in vitro activity comparable to that of vancomycin in methicillin-resistant Staphylococcus aureus (4 mg/L), S. epidermidis (2 mg/L) and methicillin-susceptible strains. Enterococcus faecalis strains were susceptible to linezolid (MIC₉₀ 2–4 mg/L), glycopeptides and β -lactams. In E. faecium , only glycopeptides (MIC₉₀ 2 mg/L) and linezolid (MIC₉₀ 2 mg/L) were active. Linezolid was the only drug active against two strains of Enterococcus showing a VanA phenotype. Owing to its antibacterial profile, linezolid represents a promising drug for the treatment of Gram-positive infections.     

In vitro activity of levofloxacin against contemporary clinical isolates of Legionella pneumophila, Mycoplasma pneumoniae and Chlamydia pneumoniae from North America and Europe

Objective   To assess the activities of levofloxacin and the comparator agents erythromycin, clarithromycin, azithromycin and doxycycline against atypical respiratory pathogens.
Methods   One hundred and forty-six Legionella pneumophila , 41 Mycoplasma pneumoniae and nine Chlamydia pneumoniae isolates were procured from various culture collections in North America and Europe and tested for susceptibility to the above agents by broth microdilution. The isolates came primarily from clinical sources and were collected from patients between 1995 and 1999.
Results   Against L. pneumophila , levofloxacin was the most active agent, with an MIC₉₀ of 0.03 mg/L, twofold more active than clarithromycin (0.06 mg/L), 16-fold more active than erythromycin and azithromycin (0.5 mg/L) and 64-fold more active than doxycycline. Against M. pneumoniae , azithromycin (MIC₉₀ ≤ 0.0005 mg/L) was the most active agent. However, two isolates of M. pneumoniae , one from the USA and one from Finland, were macrolide resistant (MIC ≥ 4 mg/L), but levofloxacin susceptible (MIC 0.25 mg/L). The geographic origin of L. pneumophila and M. pneumoniae did not affect the MIC range for any antimicrobial agent tested. Against C. pneumoniae , clarithromycin was the most active agent, with an MIC range of ≤0.008–0.03 mg/L.
Conclusions   Levofloxacin had comparable activity to the other agents tested against the atypical respiratory pathogens, confirming its potential as an alternative for empirical therapy of community-acquired pneumonia.     

In vitro activity of gatifloxacin, a new fluoroquinolone, against 204 anaerobes compared to seven other compounds

The activity of gatifloxacin, a new fluoroquinolone derivative, was compared with the activities of ciprofloxacin, levofloxacin, amoxicillin, amoxicillin–clavulanate, imipenem, clindamycin and metronidazole against 204 anaerobes isolated from clinical specimens, by MIC determination, using the reference agar dilution method. When determining the overall activity against anaerobes, the MIC_50/90 (mg/L) values were amoxicillin 16/>64, amoxicillin–clavulanate 0.125/1, imipenem 0.25/0.5, clindamycin 0.5/>256, metronidazole 1/8, ciprofloxacin 2/32, levofloxacin 1/8 and gatifloxacin 0.5/4. The broad in vitro spectrum of gatifloxacin is promising for the treatment of mixed anaerobic infections, especially those of the respiratory tract, ear, sinus, skin and soft tissues, and bite wounds. These data suggest that gatifloxacin may have a clinical role in the treatment of infections in which anaerobic pathogens are involved.     

Comparative in vitro activity of ertapenem against bacterial pathogens isolated from patients with lower respiratory tract infections

This study compared the in vitro activity of ertapenem, ceftriaxone, cefepime, ciprofloxacin and amoxicillin–clavulanate against 381 aerobic and facultative bacterial pathogens isolated from 320 patients with acute bacterial exacerbation of chronic bronchitis or community-acquired pneumonia. Streptococcus pneumoniae and Haemophilus influenzae accounted for 54.6% of the isolates. The ertapenem MIC was ≤2 mg/L for 98.4% of isolates and ≥8 mg/L for 1.0% (all methicillin-resistant Staphylococcus aureus ). Ertapenem had the most potent activity against Enterobacteriaceae, Moraxella catarrhalis , and methicillin-susceptible S. aureus , and its activity against H. influenzae and H. parainfluenzae , all strains of which were susceptible, was not altered by β -lactamase production. Only one S. pneumoniae strain, a penicillin-resistant isolate, was resistant to ertapenem. Ertapenem was highly active in vitro against pyogenic bacteria recovered from patients with community-acquired lower respiratory tract infections.     

Susceptibility of strains of Streptococcus agalactiae to macrolides and lincosamides, phenotype patterns and resistance genes

The Group B streptococcus ( Streptococcus agalactiae ) is a pathogen of increasing importance in human disease. We therefore studied the susceptibility of clinical isolates of S. agalactiae to penicillin G, erythromycin, azithromycin and clindamycin using National Committee for Clinical Laboratory Standards methodology, and we also determined the phenotypes of macrolide-lincosamide susceptibility and the resistance genes implicated in a group of selected isolates of the different phenotypes. We used 221 isolates collected between 1997 and 1999 in two Health Authority Areas in Móstoles and Granada, Spain. The minimal concentration for 90% inhibition (MIC₉₀) for penicillin G was 0.12 mg/L and all the isolates tested were susceptible. One hundred and eighty-five (83.7%) were susceptible to erythromycin and azithromycin and 191 (86.4%) were susceptible to miocamycin and clindamycin. Twenty-three isolates (10.4%) had a constitutive MLS_B phenotype, seven (3.2%) an inducible phenotype, and six (2.7%) an M phenotype. All except one of the MLS_B phenotype isolates tested ( n  = 23) carried erm genes; in two strains with the mef (A) gene, all the M phenotype ( n  = 6) isolates tested carried mef genes, while erm and mef (A) genes were absent in all the macrolide-lincosamide-susceptible ( n  = 12) isolates tested. In our environment, resistance to macrolide and lincosamide in S. agalactiae was present in 10–16% of the isolates. The majority of resistant strains had the MLS_B phenotype.     

Trends in quinolone susceptibility of Enterobacteriaceae among inpatients of a large university hospital: 1992–98

Objectives   To assess trends in quinolone susceptibility of Enterobacteriaceae isolated in a large university hospital.
Methods   Between 1992 and 1998, bacterial isolates were collected each year during a 3-month period to evaluate annual changes in susceptibility. In addition, the activities of fluoroquinolones (pefloxacin, norfloxacin, ofloxacin, ciprofloxacin) against nalidixic acid-resistant strains were determined by disk diffusion and MIC methodologies during the first and last year of the study.
Results   The susceptibility of Enterobacteriaceae to nalidixic acid was unchanged between 1992 and 1998 (86% versus 85%). However, at the species level, the susceptibility rates to nalidixic acid decreased for Escherichia coli from 92% to 89%, and for Enterobacter cloacae from 87% to 82%. In contrast, there was a 10% increase in the nalidixic acid susceptibility rates for Klebsiella pneumoniae (74% versus 83%), which was thought to be due to the control of the spread of epidemic extended-spectrum β -lactamase (ESBL)-producing strains. The overall susceptibility of the Enterobacteriaceae to the fluoroquinolones remained high during the study period, greater than 90% in the case of ciprofloxacin. However, nalidixic acid-resistant Escherichia coli showed decreased susceptibility to ciprofloxacin between 1992 and 1998, as reflected by a decrease in median zone diameter (26 mm to 19 mm), an increase in MIC₅₀ (0.25 mg/L to 1 mg/L) and a shift in MIC distribution (unimodal in 1992 to bimodal in 1998). This has resulted in the reduced susceptibility of Escherichia coli to fluoroquinolones between 1992 and 1998 (pefloxacin, 95–90%; ciprofloxacin, 99–95%).
Conclusions   The susceptibility of Escherichia coli to quinolones has decreased, and the level of susceptibility of the resistant strains has increased over the 7-year study period.     

Antimicrobial activity of LB10827, a new orally administered cephalosporin, tested against Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae

A new orally administered cephalosporin, LB10827, was compared to 16 other antimicrobial agents tested against Streptococcus pneumoniae (520 strains), Haemophilus influenzae (302 strains) and Moraxella catarrhalis (188 strains) by reference broth microdilution methods. LB10827 (MIC₉₀, 0.12 mg/L; highest MIC, 0.5 mg/L) was 8–16-fold more potent than cefdinir, cefpodoxime or cefuroxime when tested against S. pneumoniae . All Gram-negative strains were inhibited at ≤ 0.5 mg/L LB10827, which is an activity equal or superior to that of currently available and tested oral β-lactams. LB10827 appears to be a promising agent worthy of continued investigations both in vitro and in vivo.     

Antibacterial effects of Eucalyptus globulus leaf extract on pathogenic bacteria isolated from specimens of patients with respiratory tract disorders

The antibacterial activity of Eucalyptus globulus leaf extract was determined for 56 isolates of Staphylococcus aureus , 25 isolates of Streptococcus pyogenes , 12 isolates of Streptococcus pneumoniae and seven isolates of Haemophilus influenzae obtained from 200 clinical specimens of patients with respiratory tract disorders. MIC₅₀s for these species were 64, 32, 16 and 16 mg/L, respectively; MIC₉₀s were 128, 64, 32 and 32 mg/L, respectively; and MBC s were 512, 128, 64 and 64 mg/L, respectively. These results suggest that further studies to clarify the possible therapeutic role of E. globulus leaf extract in the treatment of respiratory tract infection are warranted.     

Antibiotic Susceptibilities Among Recent Clinical Isolates of Haemophilus influenzae and Moraxella catarrhalis from Fifteen Countries

 Between July 1998 and July 1999, 3,060 Haemophilus influenzae and 1,486 Moraxella catarrhalis strains were isolated in 31 centers in 15 countries in order to determine their antimicrobial susceptibilities and the presence of β-lactamase production in Haemophilus influenzae. Overall 17.1% of the Haemophilus influenzae isolates were β-lactamase positive, while more than 95% were susceptible to amoxicillin/clavulanate, cefaclor, loracarbef, cefuroxime, azithromycin and ciprofloxacin. Eleven (0.3%) isolates were β-lactamase positive and ampicillin resistant and 7 (0.2%) isolates were ciprofloxacin resistant. The minimum inhibitory concentrations for 90% of the isolates tested were lowest for ciprofloxacin (0.03) and highest for cefprozil (8) against Moraxella catarrhalis.     

The effect of carbon dioxide on susceptibility testing of azithromycin, clarithromycin and roxithromycin against clinical isolates of Streptococcus pneumoniae and Streptococcus pyogenes by broth microdilution and the Etest: Artemis Project—first-phase study

Objective: To evaluate the effect of carbon dioxide on the susceptibility testing, using broth microdilution and the Etest (AB Biodisk, Solna, Sweden), of azithromycin, clarithromycin and roxithromycin against Streptococcus pneumoniae and Streptococcus pyogenes .
Methods: Fresh clinical isolates collected from 36 hospital laboratories in 12 countries were evaluated using the Etest in the presence of carbon dioxide. The isolates were retested under ambient conditions (absence of carbon dioxide) using broth microdilution and/or the Etest.
Results: Carbon dioxide falsely elevated azithromycin, clarithromycin and roxithromycin MIC₉₀S for S. pneumoniae , determined by the Etest, approximately 12-fold. Also, the azithromycin MIC₉₀ for S. pyogenes was increased fourfold; the effect was less marked for clarithromycin and roxithromycin. When isolates were retested in the absence of carbon dioxide, using the Etest or microdilution, susceptibilities to azithroymycin were comparable to those to clarithromycin ( S. pneumoniae , 93.4% versus 91.3%; S. pyogenes , 96.4% versus 95.8%). Both organisms were less susceptible to roxithromycin ( S. pneumoniae , 71.3%; S. pyogenes , 85.7%). An internal standard control, consisting of 50 isolates each of S. pneumoniae, S. pyogenes and Haemophilus influenzae , confirmed that azithromycin susceptibility testing resulted in falsely elevated MICs.
Conclusions: Carbon dioxide falsely elevated azithromycin MICs for S. pneumoniae and S. pyogenes , with an apparent reduction in susceptibility. When the in vitro activity of azithromycin and other macrolides against S. pneumoniae and S. pyogenes is being evaluated, awareness of the pH effect is essential.     

CQ-397 and CQ-414: antimicrobial activity and spectrum of two fluoroquinolone–cephalosporin, dual-action compounds with carboxamido bonds

Objective: To evaluate the potential spectrum of activity of two novel dual-action compounds with carboxamido bonds (CQ-397 and CQ-414; Laboratories Aranda, San Rafael, Mexico) against human pathogens.
Method: Approximately 800 Gram-positive and Gram-negative aerobic clinical bacteria were tested in vitro using the Mueller-Hinton broth microdilution method of the National Committee of Clinical Laboratory Standards.
Results: CQ-397 (cefamandole+enrofloxacin) and CQ-414 (cefamandole+norfloxacin) were equally potent against Enterobacteriaceae (MIC₉₀ range, 0.06–0.5 μg/mL and 0.06-1 μg/mL, respectively). Citrobacter freundii (MIC₉₀, 4 μg/mL) and Providencia spp. (MIC₉₀,>32 μg/mL) exhibited elevated study drug MICs. Enterobacteriaceae resistant to fluoroquinolones generally remained resistant. CQ-397 and CQ-414 were active against Stenotrophomonas maltophilia (MIC₉₀, 4 μg/mL) and oxacillin-susceptible staphylococci (MIC₉₀, 0.25 μg/mL), but not oxacillin-resistant Staphylococcus aureus (MIC₉₀,>32 μg/mL), Staphylococcus epidermidis (MIC₉₀, 8 μg/mL), and enterococci (MIC₉₀s, 8 to>32 μg/mL). There was no difference in the dual-action drug activity (MIC₉₀, 2 μg/mL) between penicillin-susceptible and -resistant pneumococci. Haemophilus influenzae and Moraxella catarrhalis were very susceptible (MIC range, <0.015-0.06 μg/mL) to both compounds.
Conclusions: The activity of these novel dual-action compounds, formed from the bonding of older antimicrobials, warrants further investigation for potential human and/or animal health use, including toxicology and pharmacokinetics.     

In vitro activity of quinupristin/dalfopristin in comparison with five antibiotics against worldwide clinical isolates of staphylococci

Objective   To evaluate the in vitro activity of quinupristin/dalfopristin (Q/D), a streptogramin combination, in comparison with five antibiotics against worldwide clinical isolates of staphylococci.
Methods   A multicenter in vitro study was performed using the E test during a period of 3 months (April to June) in 1997 on fresh, clinically significant, non repetitive strains of staphylococci from patients hospitalized in 23 different hospitals in 18 countries tested.
Results   A total of 2132 staphylococcal isolates including methicillin resistant (MR), methicillin susceptible (MS) S. aureus (1003 MS, 462 MR), S. epidermidis (169 MS, 251 MR), S. haemolyticus (28 MS, 46 MR), S. hominis (28 MS, 16 MR), and coagulase negative staphylococci (86 MS, 43 MR) were analyzed.
Q/D was highly active against all species tested. MIC₉₀ (mg/L) ranged from 0.5 to 2 depending on the species. Strains had MIC≤1 mg/L in 97.6%. For S. aureus , S. epidermidis , S. hominis and other coagulase-negative staphylococci no differences in MIC₉₀ were observed for MS or MR. One dilution difference was observed for S. haemolyticus , which overall was the less susceptible species. Erythromycin resistance was observed among 57– 87% of MR-strains and was lower among MS-strains (18–56%). Erythromycin resistance had no or little influence on MIC of Q/D. In comparison to vancomycin, Q/D was two to four times more active.
Conclusions   The streptogramin combination Q/D showed an excellent in vitro activity against all staphylococcal species tested regardless of the resistance pattern to other drug classes, particularly resistance to methicillin. Q/D was two to four times more active than vancomycin and MIC values varied from 0.5–2 according to the species. The synergy of Q/D was well conserved in macrolide-resistant strains.     

Prevalence of erm methylase genes in clinical isolates of non-pigmented, rapidly growing mycobacteria

The aim of this study was to determine the frequency of erm genes coding for macrolide resistance among clinical isolates of non-pigmented rapidly growing mycobacteria (NPRGM) and to evaluate their importance in phenotypic resistance. Broth microdilution susceptibility testing was performed for all NPRGM tested. A PCR assay with consensus primers was used to evaluate the presence of erm genes among the 167 clinical isolates studied, which belonged to nine species of NPRGM; erm genes were detected in all nine species and 109 strains were erm -positive. The highest percentage of erm -positive isolates was found among Mycobacterium mageritense (100%) and the lowest among Mycobacterium mucogenicum (14%). The MICs of macrolides were found to be lower for erm -negative isolates (MIC₉₀: 2 mg/L) than for erm- positive isolates (MIC₉₀: 16 mg/L), although in some cases high MICs were found for erm -negative isolates. The finding that erm methylases are present in the majority of the species of NPRGM analysed in this study is not in agreement with conventional susceptibility studies. It therefore appears necessary to use a combination therapy to treat infections caused by NPRGM.     

Pharyngeal colonization prevalence rates for Streptococcus pyogenes and Streptococcus pneumoniae in a respiratory chemoprophylaxis intervention study using azithromycin

Objectives   A prospective assessment of the pharyngeal colonization prevalence rates for Streptococcus pyogenes and Streptococcus pneumoniae before and after an azithromycin chemoprophylaxis intervention clinical trial in a cohort of US Marine Corps trainees. In addition, the minimum inhibitory concentrations (MICs) for all streptococcal isolates, for azithromycin, penicillin, erythromycin and cefotaxime are reported.
Methods   Between November 1994 and March 1995, 1108 asymptomatic male US Marine Corps trainees, located in Southern California, were randomly assigned to one of three intervention groups: (1) weekly oral azithromycin, 500 mg ( n  = 362); (2) 1.2 MU benzathine penicillin G, intramuscularly once ( n  = 374); or (3) no chemoprophylaxis ( n  = 372). Subjects provided both a pre- and post-training pharyngeal culture and microbial analysis was conducted to determine the colonization status of each study subject.
Results   The pretraining colonization prevalence was 1.2% for S. pneumoniae and 2.4% for S. pyogenes . There was no statistical difference in pretraining prevalence between the three treatment groups for either organism. Post-training pharyngeal cultures revealed an overall prevalence of 1.1% with no difference between treatment arms. However, the overall post-training prevalence of S. pyogenes colonization increased to 4.8%, with the azithromycin group having significant evidence of protection (0.7%) in comparison with the no-treatment group (8.2%). The Etest method demonstrated no significant difference in the MIC₅₀, MIC₉₀, and MIC ranges between pre- and post-training isolates for any of the tested drugs.
Conclusion The use of azithromycin as a chemoprophylactic agent to reduce the colonization and subsequent infection of streptococcal respiratory disease among healthy adult male military recruits may be beneficial.     

Antimicrobial resistance in viridans group streptococci among patients with and without the diagnosis of cancer in the USA, Canada and Latin America

Objective   To investigate antimicrobial resistance in viridans group streptococci (VGS) among patients with and without the diagnosis of cancer in the USA, Canada and Latin America.
Methods   All bloodstream isolates of VGS collected from SENTRY centers in the Western Hemisphere between January 1997 and December 1999 were tested by reference broth microdilution methods (NCCLS). Results for isolates from patients with cancer were compared to those from other patient populations.
Results   Overall, 438 unique patient bloodstream isolates of VGS were collected during the study. Percentage susceptible/MIC₉₀ (mg/L) values for antimicrobials tested were as follows: penicillin, 66/1; erythromycin, 60/4; clindamycin, 92/0.12; cefepime, 86/1; trimethoprim–sulfamethoxazole, 80/2; ciprofloxacin, 44/> 2; gatifloxacin, 98/0.5; and vancomycin, 100/1. Of these isolates, 70 (16%) were confirmed to be from cancer patients. VGS isolates from cancer patients were less susceptible to most antimicrobials tested than were isolates from non-cancer patients. The greatest differences in susceptibility rates for cancer- versus non-cancer-associated VGS isolates were seen for ciprofloxacin (34% versus 46%, P  = 0.07) and trimethoprim–sulfamethoxazole (64% versus 83%, P  < 0.001), two agents which are often used for prophylaxis or as presumptive therapy in cancer patients.
Conclusions   Susceptibility rates for VGS isolates from cancer patients are lower than those for isolates from patients without a cancer diagnosis. These differences are greatest for agents that have seen widespread prophylactic and empirical use. Ongoing surveillance of VGS infections in this patient population is important and should help to guide therapy decisions.