MMSC 438 EXAM 1 QUESTIONS & ANSWERS
Urinary Tract normal organisms (but likely contaminants from other parts of the body) -
Answer -Staph epidermidis, streps, diphtheroids, E coli, Lactobacilli, and yeast
Some antimicrobials have a small therapeutic index, Therapeutically effective
concentrations close to... - Answer -toxic levels (Aminoglycosides and vancomycin (rise
in creatinine & BUN levels) and Chloramphenicol, linezolid (CBC & reticulocyte count
decrease))
Broad guideline to aid clinicians in deciding whether a patient is being given effective
therapy for a serious infections
▫Takes 48 hours
-Broth dilution takes overnight incubation
Plate no growth tubes to solid media - Answer -Schlichter Test (specialized screening)
Schlichter Test determines bacterial activity in - Answer -patient serum
Cloxacillin inhibits - Answer -AmpC
If test isolate produces carbapenenase, allows growth of carbapenem susceptible... -
Answer -E coli
Specialized Screening: Carbapenemase Testing•Detected by ______________
(▫Streak a lawn of carbapenem-susceptible E. coli on Mueller Hinton agar▫Place
carbapenem susceptibility disk in center▫Streak test organism from edge of disk to edge
of plate▫Incubate 16-24 hrs, ambient air, 35°C) - Answer -Modified Hodge Test (MHT)
the treatment of choice forESBL-producing bacteria like Klebsiella sp - Answer -
carbapenems
Carbapenemases initially identified and most common in - Answer -K. pneumoniae
Specialized Screening: ESBL - Answer -Confirmation testing▫Use inhibitor-potentiated
disk diffusion test
Routine MIC results▫Increased resistance to 3GC (e.g. cefotaxime, ceftriaxone,
ceftriaxone, ceftizoxime, ceftazidime, cefpodoxime), and aztreonam - Answer -
(Specialized Screening: ) ESBL
ESBLs are inhibited by - Answer -clavulanic acid
Recommend specialized ESBL sscreening with cefpodoxime disk, __ μg - Answer -10
,Testing used to detect carbapenemase production in isolates of Enterobacteriaceae -
Answer -(Specialized Screening:) Carbapenemase Testing
AmpC Beta-Lactamases
•Isolated from ______________ and other GN bacteria
•Resistance to 3GC, most penicillins and β-lactamase inhibitor/β-lactam combinations -
Answer -Enterobacteriaceae
Urinary Tract source of contaminants - Answer -urethra, vagina, perianal area, and skin
Invasion of urinary tract by MOs, usually due to bacteria ascending from the urethra
ALL sites of urinary tract may be affected - Answer -UTI (body's major defense is urine
flow along with immune defenses)
Prostatitis is prostate, pyelonephritis is kidney, ureteritis is ureter, urethritis is urethra,
cystitis is _________ - Answer -bladder
Steps of UTI include colonization in urethra, uroepithelium penetration in bladder,
bacterial ascension through ureters, and pyelonephritis leading to - Answer -acute
kidney injury
Common signs and symptoms of UTI (bladder, urethra) - Answer -Dysuria (pain or
burning in urination), Pyuria (WBCs in urine over 10/hpf, positive leukocyte esterase)
and hemoglobinuria and proteinuria
All those at risk for UTIs - Answer -Sexually active females, pregnant females, post-
menopausal females, older males, infants, catheter patients, and patients with structural
or physiological renal disease
If ESBL +, may seem susceptible to penicillins, cephalosporins and monobactam with in
vitro testing, but report all as _____________ - Answer -resistant
Enzyme mediating resistance against extended-spectrum cephalosporins in
Enterobacteriaceae
▫3rd generation cephalosporins and older β-lactams:
Penicillins
Cefotaxime, ceftriaxone, ceftizoxime, ceftazidime
Aztreonam - Answer -ESBL
Among Haemophilus sp., N. gonorrhoeae, M. catarrhalis, positive test indicates
resistance to penicillin, ampicillin, and amoxicillin - Answer -Beta-lactamase test
Among staphylococci and enterococci, positive test indicates resistance to penicillin,
ampicillin, and carbenicillin - Answer -Beta-lactamase test
, Specialized screening- MRSA. if resistant to methicillin or oxacillin (1 μg)▫Report isolate
resistant to all... - Answer -β-lactam agents (e.g., penicillin, cephalosporins, β-lactam/β-
lactamase inhibitor combinations, and imipenem)
Usually resistant to other agents, such as clindamycin, erythromycin, tetracycline,
gentamicin and SXT - Answer -MRSA (Usually sensitive to vancomycin)
MRSA screening:
Determine isolate sensitivity to Methicillin or oxacillin
•CLSI recommends _____________
(▫Better inducer of mecA gene▫Clearer endopoints with heteroresistant populations) -
Answer -cefoxitin disk
Women are more at risk for UTIs bc - Answer -shorter proximity (smaller urethra closer
to source of infection ALSO from spermicide contraceptives and sex=honeymoon
cystitis moving pathogens around)
MIC of patient strain compared to MIC of lab strain - Answer -resistance ratio
________________
•Therapeutic Considerations
▫Mutations are common (drug resistance is high)
Multi drug-resistant (MDR)
Extensively drug-resistant
▫Multiple drugs needed to kill and prevent emergence of ________ - Answer -
mycobacterial chemotherapy, MDR-TB
Men are less likely to have UTIs due to longer urethra, antimicrobial secretions from
prostate, older men are more at risk bc... - Answer -larger prostate impeding flow of
urine
Complicated UTI - Answer -infection in patients with structural and/or functional
abnormalities of the urinary tract (like urinary obstruction or spinal cord injury)
Uncomplicated UTI - Answer -infection of healthy women, no structural or functional
abnormalities
Infection with over 10^5 CFU/mL WITHOUT SYMPTOMS - Answer -Asymptomatic UTI
(pregnancy and the elderly)
Cystitis symptoms
LOW numbers of bacteria in urine- under 10^2 bacteria/mL
painful urination (dysuria) - Answer -Acute urethral syndrome
Urinary Tract normal organisms (but likely contaminants from other parts of the body) -
Answer -Staph epidermidis, streps, diphtheroids, E coli, Lactobacilli, and yeast
Some antimicrobials have a small therapeutic index, Therapeutically effective
concentrations close to... - Answer -toxic levels (Aminoglycosides and vancomycin (rise
in creatinine & BUN levels) and Chloramphenicol, linezolid (CBC & reticulocyte count
decrease))
Broad guideline to aid clinicians in deciding whether a patient is being given effective
therapy for a serious infections
▫Takes 48 hours
-Broth dilution takes overnight incubation
Plate no growth tubes to solid media - Answer -Schlichter Test (specialized screening)
Schlichter Test determines bacterial activity in - Answer -patient serum
Cloxacillin inhibits - Answer -AmpC
If test isolate produces carbapenenase, allows growth of carbapenem susceptible... -
Answer -E coli
Specialized Screening: Carbapenemase Testing•Detected by ______________
(▫Streak a lawn of carbapenem-susceptible E. coli on Mueller Hinton agar▫Place
carbapenem susceptibility disk in center▫Streak test organism from edge of disk to edge
of plate▫Incubate 16-24 hrs, ambient air, 35°C) - Answer -Modified Hodge Test (MHT)
the treatment of choice forESBL-producing bacteria like Klebsiella sp - Answer -
carbapenems
Carbapenemases initially identified and most common in - Answer -K. pneumoniae
Specialized Screening: ESBL - Answer -Confirmation testing▫Use inhibitor-potentiated
disk diffusion test
Routine MIC results▫Increased resistance to 3GC (e.g. cefotaxime, ceftriaxone,
ceftriaxone, ceftizoxime, ceftazidime, cefpodoxime), and aztreonam - Answer -
(Specialized Screening: ) ESBL
ESBLs are inhibited by - Answer -clavulanic acid
Recommend specialized ESBL sscreening with cefpodoxime disk, __ μg - Answer -10
,Testing used to detect carbapenemase production in isolates of Enterobacteriaceae -
Answer -(Specialized Screening:) Carbapenemase Testing
AmpC Beta-Lactamases
•Isolated from ______________ and other GN bacteria
•Resistance to 3GC, most penicillins and β-lactamase inhibitor/β-lactam combinations -
Answer -Enterobacteriaceae
Urinary Tract source of contaminants - Answer -urethra, vagina, perianal area, and skin
Invasion of urinary tract by MOs, usually due to bacteria ascending from the urethra
ALL sites of urinary tract may be affected - Answer -UTI (body's major defense is urine
flow along with immune defenses)
Prostatitis is prostate, pyelonephritis is kidney, ureteritis is ureter, urethritis is urethra,
cystitis is _________ - Answer -bladder
Steps of UTI include colonization in urethra, uroepithelium penetration in bladder,
bacterial ascension through ureters, and pyelonephritis leading to - Answer -acute
kidney injury
Common signs and symptoms of UTI (bladder, urethra) - Answer -Dysuria (pain or
burning in urination), Pyuria (WBCs in urine over 10/hpf, positive leukocyte esterase)
and hemoglobinuria and proteinuria
All those at risk for UTIs - Answer -Sexually active females, pregnant females, post-
menopausal females, older males, infants, catheter patients, and patients with structural
or physiological renal disease
If ESBL +, may seem susceptible to penicillins, cephalosporins and monobactam with in
vitro testing, but report all as _____________ - Answer -resistant
Enzyme mediating resistance against extended-spectrum cephalosporins in
Enterobacteriaceae
▫3rd generation cephalosporins and older β-lactams:
Penicillins
Cefotaxime, ceftriaxone, ceftizoxime, ceftazidime
Aztreonam - Answer -ESBL
Among Haemophilus sp., N. gonorrhoeae, M. catarrhalis, positive test indicates
resistance to penicillin, ampicillin, and amoxicillin - Answer -Beta-lactamase test
Among staphylococci and enterococci, positive test indicates resistance to penicillin,
ampicillin, and carbenicillin - Answer -Beta-lactamase test
, Specialized screening- MRSA. if resistant to methicillin or oxacillin (1 μg)▫Report isolate
resistant to all... - Answer -β-lactam agents (e.g., penicillin, cephalosporins, β-lactam/β-
lactamase inhibitor combinations, and imipenem)
Usually resistant to other agents, such as clindamycin, erythromycin, tetracycline,
gentamicin and SXT - Answer -MRSA (Usually sensitive to vancomycin)
MRSA screening:
Determine isolate sensitivity to Methicillin or oxacillin
•CLSI recommends _____________
(▫Better inducer of mecA gene▫Clearer endopoints with heteroresistant populations) -
Answer -cefoxitin disk
Women are more at risk for UTIs bc - Answer -shorter proximity (smaller urethra closer
to source of infection ALSO from spermicide contraceptives and sex=honeymoon
cystitis moving pathogens around)
MIC of patient strain compared to MIC of lab strain - Answer -resistance ratio
________________
•Therapeutic Considerations
▫Mutations are common (drug resistance is high)
Multi drug-resistant (MDR)
Extensively drug-resistant
▫Multiple drugs needed to kill and prevent emergence of ________ - Answer -
mycobacterial chemotherapy, MDR-TB
Men are less likely to have UTIs due to longer urethra, antimicrobial secretions from
prostate, older men are more at risk bc... - Answer -larger prostate impeding flow of
urine
Complicated UTI - Answer -infection in patients with structural and/or functional
abnormalities of the urinary tract (like urinary obstruction or spinal cord injury)
Uncomplicated UTI - Answer -infection of healthy women, no structural or functional
abnormalities
Infection with over 10^5 CFU/mL WITHOUT SYMPTOMS - Answer -Asymptomatic UTI
(pregnancy and the elderly)
Cystitis symptoms
LOW numbers of bacteria in urine- under 10^2 bacteria/mL
painful urination (dysuria) - Answer -Acute urethral syndrome
