J K Rasheed

Publications of J K Rasheed

• Evaluation of methods to identify the Klebsiella pneumoniae carbapenemase in Enterobacteriaceae.

  Authors: K F Anderson, D R Lonsway, J K Rasheed, J Biddle, B Jensen, L K McDougal, R B Carey, A Thompson, S Stocker, B Limbago, J B Patel

  Journal of clinical microbiology. 09/2007; 45(8):2723-5.

  The Klebsiella pneumoniae carbapenem (KPC) beta-lactamase occurs in Enterobacteriaceae and can confer resistance to all beta-lactam agents including carbapenems. The enzyme may confer low-levelThe Klebsiella pneumoniae carbapenem (KPC) beta-lactamase occurs in Enterobacteriaceae and can confer resistance to all beta-lactam agents including carbapenems. The enzyme may confer low-level carbapenem resistance, and the failure of susceptibility methods to identify this resistance has been reported. Automated and nonautomated methods for carbapenem susceptibility were evaluated for identification of KPC-mediated resistance. Ertapenem was a more sensitive indicator of KPC resistance than meropenem and imipenem independently of the method used. Carbapenemase production could be confirmed with the modified Hodge test.

• High interlaboratory reproducibility of DNA sequence-based typing of bacteria in a multicenter study.

  Authors: M Aires de Sousa, K Boye, H de Lencastre, A Deplano, M C Enright, J Etienne, A Friedrich, D Harmsen, A Holmes, X.W. Huijsdens [......] J K Rasheed, E. Spalburg, B Strommenger, M J Struelens, F C Tenover, J Thomas, U Vogel, H Westh, J Xu, W Witte

  Journal of clinical microbiology. 03/2006; 44(2):619-21.

  Current DNA amplification-based typing methods for bacterial pathogens often lack interlaboratory reproducibility. In this international study, DNA sequence-based typing of the Staphylococcus aureusCurrent DNA amplification-based typing methods for bacterial pathogens often lack interlaboratory reproducibility. In this international study, DNA sequence-based typing of the Staphylococcus aureus protein A gene (spa, 110 to 422 bp) showed 100% intra- and interlaboratory reproducibility without extensive harmonization of protocols for 30 blind-coded S. aureus DNA samples sent to 10 laboratories. Specialized software for automated sequence analysis ensured a common typing nomenclature.

• High interlaboratory reproducibility of DNA sequence-based typing of bacteria in a multicenter study

  Authors: M. ires-de-Sousa, K. Boye, Lencastre H. de, A. Deplano, M.C. Enright, J. Etienne, A. Friedrich, D. Harmsen, A. Holmes, X.W. Huijsdens [......] J.K. Rasheed, E. Spalburg, B. Strommenger, M.J. Struelens, F.C. Tenover, J. Thomas, U. Vogel, H. Westh, J. Xu, W. Witte

  J.Clin.Microbiol. 02/2006; 44.

  Current DNA amplification-based typing methods for bacterial pathogens often lack interlaboratory reproducibility. In this international study, DNA sequence-based typing of the Staphylococcus aureusCurrent DNA amplification-based typing methods for bacterial pathogens often lack interlaboratory reproducibility. In this international study, DNA sequence-based typing of the Staphylococcus aureus protein A gene (spa, 110 to 422 bp) showed 100% intra- and interlaboratory reproducibility without extensive harmonization of protocols for 30 blind-coded S. aureus DNA samples sent to 10 laboratories. Specialized software for automated sequence analysis ensured a common typing nomenclature

• Characterization of clinical isolates of Klebsiella pneumoniae from 19 laboratories using the National Committee for Clinical Laboratory Standards extended-spectrum beta-lactamase detection methods.

  Authors: C D Steward, J K Rasheed, S K Hubert, J W Biddle, P M Raney, G J Anderson, P P Williams, K L Brittain, A Oliver, J E McGowan, F C Tenover

  Journal of clinical microbiology. 09/2001; 39(8):2864-72.

  Extended-spectrum beta-lactamases (ESBLs) are enzymes found in gram-negative bacilli that mediate resistance to extended-spectrum cephalosporins and aztreonam. In 1999, the National Committee forExtended-spectrum beta-lactamases (ESBLs) are enzymes found in gram-negative bacilli that mediate resistance to extended-spectrum cephalosporins and aztreonam. In 1999, the National Committee for Clinical Laboratory Standards (NCCLS) published methods for screening and confirming the presence of ESBLs in Klebsiella pneumoniae, Klebsiella oxytoca, and Escherichia coli. To evaluate the confirmation protocol, we tested 139 isolates of K. pneumoniae that were sent to Project ICARE (Intensive Care Antimicrobial Resistance Epidemiology) from 19 hospitals in 11 U.S. states. Each isolate met the NCCLS screening criteria for potential ESBL producers (ceftazidime [CAZ] or cefotaxime [CTX] MICs were > or =2 microg/ml for all isolates). Initially, 117 (84%) isolates demonstrated a clavulanic acid (CA) effect by disk diffusion (i.e., an increase in CAZ or CTX zone diameters of > or =5 mm in the presence of CA), and 114 (82%) demonstrated a CA effect by broth microdilution (reduction of CAZ or CTX MICs by > or =3 dilutions). For five isolates, a CA effect could not be determined initially by broth microdilution because of off-scale CAZ results. However, a CA effect was observed in two of these isolates by testing cefepime and cefepime plus CA. The cefoxitin MICs for 23 isolates that failed to show a CA effect by broth microdilution were > or =32 microg/ml, suggesting either the presence of an AmpC-type beta-lactamase or porin changes that could mask a CA effect. By isoelectric focusing (IEF), 7 of the 23 isolates contained a beta-lactamase with a pI of > or =8.3 suggestive of an AmpC-type beta-lactamase; 6 of the 7 isolates were shown by PCR to contain both ampC-type and bla(OXA) genes. The IEF profiles of the remaining 16 isolates showed a variety of beta-lactamase bands, all of which had pIs of < or =7.5. All 16 isolates were negative by PCR with multiple primer sets for ampC-type, bla(OXA), and bla(CTX-M) genes. In summary, 83.5% of the K. pneumoniae isolates that were identified initially as presumptive ESBL producers were positive for a CA effect, while 5.0% contained beta-lactamases that likely masked the CA effect. The remaining 11.5% of the isolates studied contained beta-lactamases that did not demonstrate a CA effect. An algorithm based on phenotypic analyses is suggested for evaluation of such isolates.

• Possible horizontal transfer of the vanB2 gene among genetically diverse strains of vancomycin-resistant Enterococcus faecium in a Korean hospital.

  Authors: W G Lee, J A Jernigan, J K Rasheed, G J Anderson, F C Tenover

  Journal of clinical microbiology. 04/2001; 39(3):1165-8.

  A total of 25 isolates of vanB-containing Enterococcus faecium were recovered from patients in a single Korean hospital over a 20-month period. There were two distinct vanB2 patterns among the 11A total of 25 isolates of vanB-containing Enterococcus faecium were recovered from patients in a single Korean hospital over a 20-month period. There were two distinct vanB2 patterns among the 11 pulsed-field gel electrophoresis types; 17 contained the prototype vanB2 and 8 contained a novel vanB2 with a 177-bp deletion in vanY(B). Both vanB2 genes were transmissible in vitro at a mean frequency of 1.1 x 10(-8) transconjugants/donor. These results suggest the horizontal spread of vanB2 is occurring among genetically diverse strains of E. faecium in Korean hospitals.

• Emergence of domestically acquired ceftriaxone-resistant Salmonella infections associated with AmpC beta-lactamase.

  Authors: E F Dunne, P D Fey, P Kludt, R Reporter, F Mostashari, P Shillam, J Wicklund, C Miller, B Holland, K Stamey, T J Barrett, J K Rasheed, F C Tenover, E M Ribot, F J Angulo

  JAMA : the journal of the American Medical Association. 01/2001; 284(24):3151-6.

  CONTEXT: Ceftriaxone, an expanded-spectrum cephalosporin, is an antimicrobial agent commonly used to treat severe Salmonella infections, especially in children. Ceftriaxone-resistant SalmonellaCONTEXT: Ceftriaxone, an expanded-spectrum cephalosporin, is an antimicrobial agent commonly used to treat severe Salmonella infections, especially in children. Ceftriaxone-resistant Salmonella infections have recently been reported in the United States, but the extent of the problem is unknown. OBJECTIVES: To summarize national surveillance data for ceftriaxone-resistant Salmonella infections in the United States and to describe mechanisms of resistance. DESIGN AND SETTING: Case series and laboratory evaluation of human isolates submitted to the Centers for Disease Control and Prevention from 17 state and community health departments participating in the National Antimicrobial Resistance Monitoring System (NARMS) for enteric bacteria between 1996 and 1998. PATIENTS: Patients with ceftriaxone-resistant Salmonella infections between 1996 and 1998 were interviewed and isolates with decreased ceftriaxone susceptibility were further characterized. MAIN OUTCOME MEASURES: Exposures and illness outcomes, mechanisms of resistance. RESULTS: The prevalence of ceftriaxone-resistant Salmonella was 0.1% (1 of 1326) in 1996, 0.4% (5 of 1301) in 1997, and 0.5% (7 of 1466) in 1998. Ten (77%) of the 13 patients with ceftriaxone-resistant infections were aged 18 years or younger. The patients lived in 8 states (California, Colorado, Kansas, Massachusetts, Maryland, Minnesota, New York, and Oregon). Nine (82%) of 11 patients interviewed did not take antimicrobial agents and 10 (91%) did not travel outside the United States before illness onset. Twelve of the 15 Salmonella isolates with ceftriaxone minimum inhibitory concentrations of 16 microg/mL or higher were serotype Typhimurium but these isolates had different pulsed-field gel electrophoresis patterns. Thirteen of these 15 isolates collected between 1996 and 1998 were positive for a 631-base pair polymerase chain reaction product obtained by using primers specific for the ampC gene of Citrobacter freundii. CONCLUSIONS: Domestically acquired ceftriaxone-resistant Salmonella has emerged in the United States. Most ceftriaxone-resistant Salmonella isolates had similar AmpC plasmid-mediated resistance.

• Characterization of the extended-spectrum beta-lactamase reference strain, Klebsiella pneumoniae K6 (ATCC 700603), which produces the novel enzyme SHV-18.

  Authors: J K Rasheed, G J Anderson, H Yigit, A M Queenan, A Doménech-Sánchez, J M Swenson, J W Biddle, M J Ferraro, G A Jacoby, F C Tenover

  Antimicrobial agents and chemotherapy. 10/2000; 44(9):2382-8.

  Klebsiella pneumoniae K6 (ATCC 700603), a clinical isolate, is resistant to ceftazidime and other oxyimino-beta-lactams. A consistent reduction in the MICs of oxyimino-beta-lactams by at least 3Klebsiella pneumoniae K6 (ATCC 700603), a clinical isolate, is resistant to ceftazidime and other oxyimino-beta-lactams. A consistent reduction in the MICs of oxyimino-beta-lactams by at least 3 twofold dilutions in the presence of clavulanic acid confirmed the utility of K. pneumoniae K6 as a quality control strain for extended-spectrum beta-lactamase (ESBL) detection. Isoelectric-focusing analysis of crude lysates of K6 demonstrated a single beta-lactamase with a pI of 7.8 and a substrate profile showing preferential hydrolysis of cefotaxime compared to ceftazidime. PCR analysis of total bacterial DNA from K6 identified the presence of a bla(SHV) gene. K6 contained two large plasmids with molecular sizes of approximately 160 and 80 kb. Hybridization of plasmid DNA with a bla(SHV)-specific probe indicated that a bla(SHV) gene was encoded on the 80-kb plasmid, which was shown to transfer resistance to ceftazidime in conjugal mating experiments with Escherichia coli HB101. DNA sequencing of this bla(SHV)-related gene revealed that it differs from bla(SHV-1) at nine nucleotides, five of which resulted in amino acid substitutions: Ile to Phe at position 8, Arg to Ser at position 43, Gly to Ala at position 238, and Glu to Lys at position 240. In addition to the production of this novel ESBL, designated SHV-18, analysis of the outer membrane proteins of K6 revealed the loss of the OmpK35 and OmpK37 porins.

• Detection of Tn917-like sequences within a Tn916-like conjugative transposon (Tn3872) in erythromycin-resistant isolates of Streptococcus pneumoniae.

  Authors: L K McDougal, F C Tenover, L N Lee, J K Rasheed, J E Patterson, J H Jorgensen, D J LeBlanc

  Antimicrobial agents and chemotherapy. 10/1998; 42(9):2312-8.

  A series of macrolide-lincosamide-streptogramin B (MLS)-resistant pneumococcal isolates of a variety of serotypes was examined and was found to contain Tn917-like elements by DNA-DNA hybridization.A series of macrolide-lincosamide-streptogramin B (MLS)-resistant pneumococcal isolates of a variety of serotypes was examined and was found to contain Tn917-like elements by DNA-DNA hybridization. Like Tn1545, Tn917 also encodes an ermAM gene but does not mediate resistance to other antimicrobial agents. Furthermore, nucleotide sequence analyses of the DNAs flanking three of the Tn917-like elements revealed that they were inserted into orf9 of a Tn916-like element in a composite transposon-like structure (Tn3872). Other MLS-resistant strains appeared to contain Tn1545-like elements that had suffered a deletion of sequences including the aphA-3 sequences responsible for kanamycin resistance. Thus, the MLS resistance phenotype in pneumococci appears to be mediated by the ermAM present on a much wider variety of genetic elements than was previously appreciated.

• Evolution of extended-spectrum beta-lactam resistance (SHV-8) in a strain of Escherichia coli during multiple episodes of bacteremia.

  Authors: J K Rasheed, C Jay, B Metchock, F Berkowitz, L Weigel, J Crellin, C Steward, B Hill, A A Medeiros, F C Tenover

  Antimicrobial agents and chemotherapy. 04/1997; 41(3):647-53.

  Nine isolates of Escherichia coli were recovered from seven blood cultures over a period of 3 months from a 19-month-old female with aplastic anemia. Initial isolates were susceptible toNine isolates of Escherichia coli were recovered from seven blood cultures over a period of 3 months from a 19-month-old female with aplastic anemia. Initial isolates were susceptible to extended-spectrum cephalosporins, including ceftazidime (MIC, < or = 0.25 microgram/ml), but gradually became resistant to this drug (MICs, > or = 128 micrograms/ml) and other cephalosporins and the monobactam aztreonam. Molecular typing methods, including plasmid profile analysis, pulsed-field gel electrophoresis, and arbitrarily primed PCR, indicated that the nine isolates were derived from a common ancestor. Dot blot hybridization and PCR analysis of total bacterial DNA using blaSHV- and blaTEM-specific DNA probes and primers identified the presence of a blaTEM beta-lactamase gene in all of the isolates and a blaSHV gene in the isolates with elevated ceftazidime MICs. Isoelectric focusing analysis of crude lysates showed that all nine isolates contained an enzyme with a pI of 5.4 corresponding to the TEM-1 beta-lactamase, and those isolates containing an SHV-type beta-lactamase demonstrated an additional band with a pI of 7.6. The first of the ceftazidime-resistant isolates appeared to hyperproduce the SHV enzyme compared to the other resistant isolates. DNA sequencing revealed a blaSHV-1 gene in the first ceftazidime-resistant isolate and a novel blaSHV gene, blaSHV-8, with an Asp-to-Asn substitution at amino acid position 179 in the remaining four isolates. Three of the ceftazidime-resistant isolates also showed a change in porin profile. The patient had received multiple courses of antimicrobial agents during her illness, including multiple courses of ceftazidime. This collection of blood isolates from the same patient appears to represent the in vivo evolution of resistance under selective pressure of treatment with various cephalosporins.

• Identification of multiple clones of extended-spectrum cephalosporin-resistant Streptococcus pneumoniae isolates in the United States.

  Authors: L K McDougal, J K Rasheed, J W Biddle, F C Tenover

  Antimicrobial agents and chemotherapy. 10/1995; 39(10):2282-8.

  We characterized 12 isolates of Streptococcus pneumoniae with various levels of susceptibility of penicillin and extended-spectrum cephalosporins by antimicrobial susceptibility patterns, serotypes,We characterized 12 isolates of Streptococcus pneumoniae with various levels of susceptibility of penicillin and extended-spectrum cephalosporins by antimicrobial susceptibility patterns, serotypes, ribotypes, chromosomal DNA restriction patterns by pulsed-field gel electrophoresis, multilocus enzyme electrophoresis patterns, penicillin-binding protein (PBP) profiles, and DNA restriction endonuclease cleavage profiles of pbp1a, pbp2x, and pbp2b. Seven cefotaxime-resistant (MIC, > or = 2 micrograms/ml) serotype 23F isolates were related on the basis of ribotyping, pulsed-field gel electrophoresis, and multilocus enzyme electrophoresis, but they had two slightly different PBP patterns: one unique to strains for which the MIC of penicillin is high (4.0 micrograms/ml) and one unique to strains for which the MIC of penicillin is low (0.12 to 1.0 micrograms/ml). The pbp1a and pbp2x fingerprints were identical for the seven isolates; however, the pbp2b fingerprints were different. An eighth serotype 23F isolate with high-level resistance to cephalosporins was not related to the other seven isolates by typing data but was a variant of the widespread, multiresistant serotype 23F Spanish clone. The PBP profiles and fingerprints of pbp1a, pbp2x, and pbp2b were identical to those of the Spanish clone isolate. An additional serotype 6B isolate with high-level resistance to cephalosporins had unique typing profiles and was unrelated to the serotype 23F cephalosporin-resistant isolates but was related on the basis of genetic typing methods to a second serotype 6B isolate that was cephalosporin susceptible. The serotype 6B isolates had different PBP profiles and fingerprints for pbp1a, but the fingerprints for pbp2x and pbp2b were the same.

• Development of PCR assays to detect ampicillin resistance genes in cerebrospinal fluid samples containing Haemophilus influenzae.

  Authors: F C Tenover, M B Huang, J K Rasheed, D H Persing

  Journal of clinical microbiology. 12/1994; 32(11):2729-37.

  We developed PCR primers specific for the blaTEM and blaROB ampicillin resistance genes. The specificity of the primers was confirmed by testing a series of Escherichia coli isolates containing aWe developed PCR primers specific for the blaTEM and blaROB ampicillin resistance genes. The specificity of the primers was confirmed by testing a series of Escherichia coli isolates containing a variety of ampicillin resistance genes and a series of ampicillin-resistant and ampicillin-susceptible Haemophilus influenzae isolates. There was a perfect correlation between ampicillin MICs, the presence of beta-lactamase (as determined by the nitrocefin test), and the results with the blaTEM and blaROB primers. Isolates of H. influenzae and Streptococcus pneumoniae obtained from 25 frozen cerebrospinal fluid (CSF) specimens were also tested. Four of 14 H. influenzae isolates were positive with the blaTEM primers; none were positive with the blaROB primers. Ampicillin MICs were determined for the H. influenzae isolates, and penicillin MICs were determined for the S. pneumoniae isolates. Only the four PCR-positive H. influenzae isolates had elevated MICs of ampicillin and were beta-lactamase positive. None of the H. influenzae isolates contained the blaROB gene, and none of the S. pneumoniae isolates produced positive reactions with either primer set. We then used universal primers directed to conserved regions of rRNA and a Haemophilus detection probe to identify which of the 25 frozen samples of CSF contained H. influenzae. Fourteen of the 25 CSF specimens were positive for H. influenzae, which correlated with the number of organisms obtained by culture of the CSF samples. Four of the CSF samples were positive with the blaTEM primer set, and these correlated with the four H. influenzae isolates that were positive when tested directly by PCR. The blaTEM assay required the use of native Taq polymerase because Amplitaq preparations were contaminated with vector DNA that contained the blaTEM-1 gene.