V09.1 Infection with microorganisms resistant to cephalosproins and other B-lactam antibiotics.

V09.1, however, would not be your primary diagnosis code. As it is stated in the ICD-9-CM, Category V09 is intended for use as an additional code for infections conditions classified elsewhere to indicate the presence of a drug-resistance of the infectious organism.

Per Wikipedia:

ESBL, or Extended Spectrum Beta Lactamase, are bacteria that produce enzymes that exhibit resistance to extended-spectrum (third generation) Cephalosporins (i.e.Ceftazidime, Cefotaxime, and Ceftriaxone) and Monobactams (i.e.. Aztreonam) but do not affect Cephamycins (eg. Cefoxitin and Cefotetan) or Carbapenems (i.e. Meropenem or Imipenem).

The most common ESBL-producing bacteria are Escherichia coli (E. coli), Klebsiella pneumoniae, and Klebsiella oxytoca. You'll need to dig further in the patients chart to see which of these is the culprit, and code that as your primary diagnosis, followed by V09.1.

Broad Spectrum Penicillins Amoxicillin

* Ampicillin

* Bacampicillin

* Carbenicillin Indanyl

* Mezlocillin

* Piperacillin

* Ticarcillin

Penicillins and Beta Lactamase Inhibitors

* Amoxicillin-Clavulanic Acid

* Ampicillin-Sulbactam

* Benzylpenicillin

* Cloxacillin

* Dicloxacillin

* Methicillin

* Oxacillin

* Penicillin G

* Penicillin V

* Piperacillin Tazobactam

* Ticarcillin Clavulanic Acid

* Nafcillin

Cephalosporins

* Cephalosporin I Generation

* Cefadroxil

* Cefazolin

* Cephalexin

* Cephalothin

* Cephapirin

* Cephradine

Cephalosporin II Generation

* Cefaclor

* Cefamandol

* Cefonicid

* Cefotetan

* Cefoxitin

* Cefprozil

* Ceftmetazole

* Cefuroxime

* Loracarbef

Cephalosporin III Generation

* Cefdinir

* Ceftibuten

* Cefoperazone

* Cefixime

* Cefotaxime

* Cefpodoxime proxetil

* Ceftazidime

* Ceftizoxime

* Ceftriaxone

Cephalosporin IV Generation

Cefepime

Macrolides and Lincosamines

* Azithromycin

* Clarithromycin

* Clindamycin

* Dirithromycin

* Erythromycin

* Lincomycin

* Troleandomycin

Quinolones and Fluoroquinolones

* Cinoxacin

* Ciprofloxacin

* Enoxacin

* Gatifloxacin

* Grepafloxacin

* Levofloxacin

* Lomefloxacin

* Moxifloxacin

* Nalidixic acid

* Norfloxacin

* Ofloxacin

* Sparfloxacin

* Trovafloxacin

* Oxolinic acid

* Gemifloxacin

* Perfloxacin

Carbepenems

Imipenem-Cilastatin

Meropenem

Monobactams

Aztreonam

Aminoglycosides

* Amikacin

* Gentamicin

* Kanamycin

* Neomycin

* Netilmicin

* Streptomycin

* Tobramycin

* Paromomycin

Glycopeptides

Teicoplanin

Vancomycin

Tetracyclines

* Demeclocycline

* Doxycycline

* Methacycline

* Minocycline

* Oxytetracycline

* Tetracycline

* Chlortetracycline

Sulfonamides

* Mafenide

* Silver Sulfadiazine

* Sulfacetamide

* Sulfadiazine

* Sulfamethoxazole

* Sulfasalazine

* Sulfisoxazole

* Trimethoprim-Sulfamethoxazole

* Sulfamethizole

Rifampin

Rifabutin

Rifampin

Rifapentine

Oxazolidonones

Linezolid

Streptogramins

Quinopristin Dalfopristin

Other Antibiotics

* Bacitracin

* Chloramphenicol

* Fosfomycin

* Isoniazid

* Methenamine

* Metronidazol

* Mupirocin

* Nitrofurantoin

* Nitrofurazone

* Novobiocin

* Polymyxin

* Spectinomycin

* Trimethoprim

* Colistin

* Cycloserine

* Capreomycin

* Ethionamide

* Pyrazinamide

* Para-aminosalicyclic acid

* Erythromycin ethylsuccinate