bsac user group meeting 2007 bsac recommendations for interpreting the susceptibility of urinary...
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BSAC User Group Meeting 2007BSAC User Group Meeting 2007
BSAC recommendations for BSAC recommendations for interpreting the susceptibility of interpreting the susceptibility of
urinary tract isolatesurinary tract isolates
Jenny AndrewsJenny Andrews
BSAC User Group Meeting 2007BSAC User Group Meeting 2007
UTIsUTIs
Frequency of micturitionFrequency of micturition
DysuriaDysuria
UrgencyUrgency
Suprapubic painSuprapubic pain
PyrexiaPyrexia
PyelonephritisPyelonephritis
BSAC User Group Meeting 2007BSAC User Group Meeting 2007
Bacterial causes of UTIsBacterial causes of UTIsOrganismOrganism Community Community
Acquired (%)Acquired (%)Hospital Hospital
Acquired (%)Acquired (%)
E. coliE. coli 7575 4040
P. mirabilisP. mirabilis 33 1010
Other coliformsOther coliforms 55 2525
P. aeruginosaP. aeruginosa 11 55
E. faecalisE. faecalis 55 88
S. saprophyticusS. saprophyticus 55 11
S. epidermidisS. epidermidis 22 33
BSAC User Group Meeting 2007BSAC User Group Meeting 2007
Non-bacterial causes of UTIsNon-bacterial causes of UTIs
Group Organism Infection
Viruses Adenoviruses Haemorrhagic cystitis
Human Polyoma Virus Infections in kidney and ureter
Parasites Trichomonas vaginalis Urethritis
Schistosoma haematobium
Bladder inflammation
Fungi Candida albicans UTI in immuno compromised patients
BSAC User Group Meeting 2007BSAC User Group Meeting 2007
Simple UTIsSimple UTIs
Women of child-bearing ageWomen of child-bearing ageE. coliE. coliP. mirabilisP. mirabilisKlebsiellaeKlebsiellaeEnterococciEnterococciS. saprophyticusS. saprophyticusGroup B StreptococciGroup B Streptococci
BSAC User Group Meeting 2007BSAC User Group Meeting 2007
Prevalence of organisms isolated from Prevalence of organisms isolated from samples taken in the community (female)samples taken in the community (female)
0 10 20 30 40 50 60 70 80
CNS
S. aureus
Pseudomonas
Enterobacter
Citrobacter
Enterococci
S.saprophyticus
Group B streps
P. mirabilis
Klebsiellae
E. coli
Percentage
City Hospital data
BSAC User Group Meeting 2007BSAC User Group Meeting 2007
Complicated UTIsComplicated UTIs
Male patientsMale patients
Abnormal anatomyAbnormal anatomy
CatheterisationCatheterisation
ChildrenChildren
Immunocompromised patientsImmunocompromised patients
ElderlyElderly
BSAC User Group Meeting 2007BSAC User Group Meeting 2007
Microbial causesMicrobial causes
Enterobacteriaceae Enterobacteriaceae
Non-fermentersNon-fermenters
StaphylococciStaphylococci
EnterococciEnterococci
Antibiotic-resistant strains frequently Antibiotic-resistant strains frequently isolatedisolated
BSAC User Group Meeting 2007BSAC User Group Meeting 2007
UTI in menUTI in menAge groupAge group
(years)(years)
IncidenceIncidence
(%)(%)
CommentComment
20-6020-60 <1<1 Very uncommon. Occur in Very uncommon. Occur in young men who participate in young men who participate in anal sex, who are not anal sex, who are not circumcised or whose sexual circumcised or whose sexual partner is colonised with partner is colonised with uropathogensuropathogens
60-7060-70 33
>80>80 1010
Wallach, 2001; McMurdo and Gillespie, 2000
BSAC User Group Meeting 2007BSAC User Group Meeting 2007
Conditions associated with or Conditions associated with or predisposing to lower UTI in menpredisposing to lower UTI in men
Prostatitis/Prostate enlargement Prostatitis/Prostate enlargement (common in older men)(common in older men)
Abnormal urinary tract, anatomical Abnormal urinary tract, anatomical changes,calculi and tumourschanges,calculi and tumours
Impaired host defencesImpaired host defences
Impaired renal functionImpaired renal function
Bailey 1996
BSAC User Group Meeting 2007BSAC User Group Meeting 2007
E.coliE.coli the most common pathogen in the most common pathogen in acute and chronic prostatitisacute and chronic prostatitis
KlebsiellaKlebsiella spp. and spp. and P. mirabilisP. mirabilis isolated less frequentlyisolated less frequently
Hospital acute cases may involve Hospital acute cases may involve staphylococci and occasionally staphylococci and occasionally enterococci or enterococci or PseudomonasPseudomonas spp spp
UTI in men – organisms UTI in men – organisms associated with infectionassociated with infection
BSAC User Group Meeting 2007BSAC User Group Meeting 2007
Prevalence of organisms isolated from Prevalence of organisms isolated from samples taken in the community (male)samples taken in the community (male)
0 10 20 30 40 50 60 70
Acinetobacter
C itrobacter
Morganella
Enterobacter
Group B strep
S. aureus
Serratia
Pseudomonas
CNS
Proteus
Enterococci
Klebsiellae
E. coli
Percentage
City Hospital data
BSAC User Group Meeting 2007BSAC User Group Meeting 2007
Laboratory diagnosisLaboratory diagnosisMid Stream UrineMid Stream Urine
Low epithelial cell count Low epithelial cell count
Pyuria/haematuriaPyuria/haematuria
Semi-quantitative cultureSemi-quantitative culture
101055 cfu/ml bacteria considered significant cfu/ml bacteria considered significant
Identification (some laboratories do not ID Identification (some laboratories do not ID urine isolates) and susceptibility testingurine isolates) and susceptibility testing
BSAC User Group Meeting 2007BSAC User Group Meeting 2007
BSAC: Systemic recommendationsBSAC: Systemic recommendationsNon-species specificNon-species specific
Table 6: MIC and zone breakpoints for Enterobacteriaceae (including Salmonella and Shigella spp.).
MIC breakpoint (mg/L)Interpretation of zone
diameters (mm)
Antibiotic R > I S Disc content (µg)
R I S
Amikacin1 16 16 8 30 15 16-18 19
Amoxicillin2 16 16 8 10 11 12-14 15
Ampicillin2 16 16 8 10 11 12-14 15
Aztreonam3 8 2-8 1 30 22 23-27 28
Cefaclor 1 - 1 30 34 - 35
Cefamandole4,5 8 - 8 30 19 - 20
Cefepime 8 2-8 1 30 26 27-31 32
Cefixime 1 - 1 5 19 - 20
BSAC User Group Meeting 2007BSAC User Group Meeting 2007
BSAC: Species specific breakpoints for simple UTIsBSAC: Species specific breakpoints for simple UTIs
Interpretation of zone diameters (mm)
MIC breakpoint (mg/L) Coliforms Escherichia coli Proteus mirabilis
Antibiotic R > I S Disc content (µg) R I S R
I S R
I S
Amoxicillin5 32 - 32 25 11 - 12 11 - 12 11 - 12
Ampicillin5 32 - 32 25 11 - 12 11 - 12 11 - 12
Cefalexin6 32 - 32 30 - - - 15 - 16 11 - 12
Ciprofloxacin 4 - 4 1 19 - 20 19 - 20 19 - 20
Co-amoxiclav 32 - 32 20/10 11 - 12 11 - 12 11 - 12
Fosfomycin7,8 128 - 128 200/50 - - - 19 - 20 33 - 34
Mecillinam9 8 - 8 10 - - - 13 - 14 13 - 14
Nalidixic acid 16 - 16 30 17 - 18 17 - 18 17 - 18
Nitrofurantoin 32 - 32 200 - - - 19 - 20 - - -
Norfloxacin 4 - 4 2 15 - 16 15 - 16 15 - 16
Temocillin 32 - 32 30 11 - 12 11 - 12 11 - 12
Trimethoprim 2 - 2 2.5 16 - 17 16 - 17 16 - 17
NB. These recommendations are for organisms associated with uncomplicated urinary tract infections. For complicated infections systemic recommendations should be used.
BSAC User Group Meeting 2007BSAC User Group Meeting 2007
Interpretation of zone diameters (mm)
MIC breakpoint (mg/L)
Enterococci Staphylococcus saprophyticus
Group B streptococci
Antibiotic R > I S Disc content (µg)
R I S R I S R I S
Ampicillin 32 - 32 25 19 - 20 25 - 26 25 - 26
Cefalexin3 32 - 32 30 - - - - - - 23 - 24
Ciprofloxacin 4 - 4 1 11 - 12 17 - 18 12 - 13
Ciprofloxacin 4 - 4 5 15 - 16 - - - 18 - 19
Co-amoxiclav 32 - 32 20/10 20 - 21 27 - 28 27 - 28
Fosfomycin4 128 - 128 200/50 19 - 20 19 - 20 - - -
Mecillinam 64 - 64 50 - - - 9 - 10 - - -
Nalidixic acid 16 - 16 30 17 - 18 - - - - - -
Nitrofurantoin 32 - 32 200 14 - 15 19 - 20 19 - 20
Norfloxacin 4 - 4 2 15 - 16 - - - - - -
Trimethoprim5 2 - 2 2.5 21 - 22 14 - 15 15 - 16
NB. These recommendations are for organisms associated with uncomplicated urinary tract infections. For complicated infections and infections caused by Staphylococcus aureus and Staphylococcus epidermidis, which are associated with more serious infections, systemic recommendations should be used.
BSAC: Species specific breakpoints for simple UTIsBSAC: Species specific breakpoints for simple UTIs
BSAC User Group Meeting 2007BSAC User Group Meeting 2007
Organism IdentificationOrganism Identification
Essential for Essential for interpretation of interpretation of susceptibility susceptibility
Chromogenic mediaChromogenic media
BSAC User Group Meeting 2007BSAC User Group Meeting 2007
Chromogenic agar Chromogenic agar (6570 UTI)(6570 UTI)
"Coliforms"
TDA +
E.coli
Klebsiella-Enterobacter-Serratia
28.6%
Proteus-Morganella-Providencia
6.9%
72.5%
Data presented by Trevor Winstanley at User Group meetings in 2005 (Power Point presentation available on the BSAC web site (www.bsac.org.uk)
BSAC User Group Meeting 2007BSAC User Group Meeting 2007
BSAC recommendationsBSAC recommendations
The recommendations are for organisms The recommendations are for organisms associated with uncomplicated urinary associated with uncomplicated urinary tract infectionstract infectionsFor complicated infections systemic For complicated infections systemic recommendations should be usedrecommendations should be usedFor infections caused by For infections caused by S. aureusS. aureus and and S. epidermidisS. epidermidis, which are associated with , which are associated with more serious infections, systemic more serious infections, systemic recommendations should be usedrecommendations should be used
BSAC User Group Meeting 2007BSAC User Group Meeting 2007
BSAC recommendationsBSAC recommendations
If an organism is isolated from multiple If an organism is isolated from multiple sites, for example from blood and urine, sites, for example from blood and urine, interpretation of susceptibility should be interpretation of susceptibility should be made with regard to the systemic site.made with regard to the systemic site.
Direct susceptibility tests on urine may be Direct susceptibility tests on urine may be performed as long as the inoculum gives performed as long as the inoculum gives semi-confluent growth.semi-confluent growth.
BSAC User Group Meeting 2007BSAC User Group Meeting 2007
BSAC recommendationsBSAC recommendations
In the absence of definitive organism In the absence of definitive organism identification, use the recommendations identification, use the recommendations most appropriate for the presumptive most appropriate for the presumptive identification, accepting that on some identification, accepting that on some occasions the interpretation may be occasions the interpretation may be incorrect. A more cautious approach is to incorrect. A more cautious approach is to use systemic recommendationsuse systemic recommendations
BSAC User Group Meeting 2007BSAC User Group Meeting 2007
BSAC recommendationsBSAC recommendations
The identification of Enterobacteriaceae to The identification of Enterobacteriaceae to species level is essential before applying species level is essential before applying expert rule for the interpretation of expert rule for the interpretation of susceptibility e.g. recommendations for susceptibility e.g. recommendations for ampicillin/amoxicillin are for ampicillin/amoxicillin are for E. coliE. coli and and P. P. mirabilismirabilis not for species that have not for species that have chromosomal penicillinase (chromosomal penicillinase (KlebsiellaKlebsiella spp.) or those that typically have inducible spp.) or those that typically have inducible AmpC enzymes (e.g. AmpC enzymes (e.g. EnterobacterEnterobacter spp., spp., CitrobacterCitrobacter spp. and spp. and SerratiaSerratia spp.) spp.)
BSAC User Group Meeting 2007BSAC User Group Meeting 2007
Under review by EUCAST/BSACUnder review by EUCAST/BSAC
Use of trimethoprim for the treatment Use of trimethoprim for the treatment of enterococciof enterococci
The clinical efficacy of mecillinam in The clinical efficacy of mecillinam in the treatment of ESBL infectionsthe treatment of ESBL infections
BSAC User Group Meeting 2007BSAC User Group Meeting 2007
Gaps in the “Coliform” Gaps in the “Coliform” recommendationsrecommendations
““Coliform” means like an Coliform” means like an E. coliE. coli, the , the recommendations should not be used for recommendations should not be used for EnterobacterEnterobacter spp. etc. spp. etc.
ID to species level is essential for the ID to species level is essential for the correct interpretationcorrect interpretation
BSAC User Group Meeting 2007BSAC User Group Meeting 2007
Should nalidixic acid be used to Should nalidixic acid be used to detect FQ resistance?detect FQ resistance?
Using nalidixic acid alone 25-40% of Using nalidixic acid alone 25-40% of isolates with LLR will be reported resistant isolates with LLR will be reported resistant to ciprofloxacinto ciprofloxacin
Organisms with LLR are probably Organisms with LLR are probably susceptible in uncomplicated infections susceptible in uncomplicated infections because of the high concentration of drug because of the high concentration of drug in urinein urine
BSAC User Group Meeting 2007BSAC User Group Meeting 2007
SummarySummary
BSAC urinary breakpoints are for simple UTIsBSAC urinary breakpoints are for simple UTIsFor complicated infections systemic For complicated infections systemic recommendations should be usedrecommendations should be usedID is necessary for the interpretation of ID is necessary for the interpretation of susceptibility and the application of expert rules susceptibility and the application of expert rules (see the Power Point presentation on the BSAC (see the Power Point presentation on the BSAC web site for the User Group Meeting in 2005 web site for the User Group Meeting in 2005 Trevor Winstanley “Expert rules and inexpensive Trevor Winstanley “Expert rules and inexpensive identification methods”)identification methods”) EUCAST are preparing a document on expert EUCAST are preparing a document on expert rules that should be available at the end of the rules that should be available at the end of the yearyear