(extended-spectrum beta-lactamase (ESBL
Members of the family Enterobacteriaceae commonly express plasmid-encoded β-lactamases (e.g., TEM-1, TEM-2, and SHV-1). which confer resistance to penicillins but not to expanded-spectrum cephalosporins. These cephalosporins include cefotaxime, ceftriaxone, and ceftazidime, as well as the oxyimino-monobactam aztreonam. Thus ESBLs confer resistance to these antibiotics and related oxyimino-beta lactams. In typical circumstances, they derive from genes for TEM-1, TEM-2, or SHV-1 by mutations that alter the amino acid configuration around the active site of these β-lactamases. This extends the spectrum of β-lactam antibiotics susceptible to hydrolysis by these enzymes. An increasing number of ESBLs not of TEM or SHV lineage have recently been described. The ESBLs are frequently plasmid encoded. Plasmids responsible for ESBL production frequently carry genes encoding resistance to other drug classes (for example, aminoglycosides). Therefore, antibiotic options in the treatment of ESBL-producing organisms are extremely limited. Carbapenems are the treatment of choice for serious infections due to ESBL-producing organisms, yet carbapenem-resistant isolates have recently been reported. ESBL-producing organisms may appear susceptible to some extended-spectrum cephalosporins. However, treatment with such antibiotics has been associated with high failure rates

فى انواع من البكتيريا السالبة مثل Gardenella vaginalis ممكن تنمو على CNA


فعلا وجود مستعمرات مخاطية من الكلابسيلا نتيجة وجود الحافظة ( الكابسول )

thanks alot
rasmya & عوني يوسف

Gardenella vaginalis !! I think it is gram positive bacilli !!a

anyway, my question was why some gram negative growth in CNA??????a

thanks again

Gardenella vaginalis variable bacteria

i.e in exponential phase of growth appeare as G-positive
but
when G .vaginalis ages appear as G-negative because the layers of peptidglycan becomes too thin to retain crystal violet -iodin aggregates

مررره شكرآ ع التوضيح وربي يعطيك العافيه

ولقيت جواب حق سؤالي أخييييرآ D:

colisten & nalidaxic acid in CNA are antibiotics so,some G-negative bacteria "like proteus" resistance to colisten & they can grow in CNA

comment plz