"Occurrence of bla CTX-MGp1 and bla CTX-MGp26 in third generation cephalosporin-resistant and carbapenem- resistant bacterial isolates from southwest region of Saudi Arabia-a preliminary study".

This study was intended to identify the genes responsible for ESBL- and carbapenemase-producing bacterial isolates obtained from Jizan region. A hospital-based cross-sectional study was conducted over a period of 3 months (15th November 2018-15th February 2019). Fifty non-duplicate, 3rd-generation cephalosporin and carbapenem-resistant isolates were collected from microbiology lab of a tertiary care hospital in Jizan province and were screened for ESBLs and MBLs by phenotypic methods (CDT). The positive isolates (by phenotypic method) were then scanned for the presence of bla ESBLs and bla NDM-1 genes, respectively, by PCR. As a result, 10% isolates showed imipenem-cephalosporin co-resistance whereas 92% (46/50) of isolates were found to be ESBL producers by CDT. The maximum occurrence was observed for bla CTX-M (70%), followed by bla SHV (16%) and least occurrence was noted for bla TEM (12%). Moreover, 97% isolates (34/35) were of bla CTX-MGroup1 but one isolate showed the presence of bla CTX-M Group26. Despite the co-resistance of cephalosporin and carbapenem, 14% (7/50) were found to be MBL producer on phenotypic detection by Combination Disc Test (CDT), whereas all the isolates were found to be negative for bla NDM-1. Hence bla CTX-MGroup1 is present in quite high fraction followed by bla SHV in the bacterial isolates of Jizan region. Moreover, the occurrence of bla CTX-M Group1 and bla CTX-M Group26 in clinical isolates from the Jizan region of Saudi Arabia has been reported for the first time.

Phenotypic and molecular characterization of cefotaximases, temoniera, and sulfhydryl variable ß-lactamases in Pseudomonas and Acinetobacter isolates in an Indian tertiary health-care center.

BACKGROUND: Cefotaximases (CTX-M), temoniera (TEM), and sulfhydryl variable (SHV) constitute a rapidly growing cluster of enzymes that have disseminated geographically. They are spreading to species other than Enterobacteriaceae and might be responsible for the presence of blaCTX-M,blaTEM, and blaSHVgenes in Pseudomonas and Acinetobacter spp. The present study was designed to characterize CTX-M, TEM, and SHV phenotypically and genotypically in Pseudomonas and Acinetobacter spp. MATERIALS AND METHODS: A total of 90 isolates (73 Pseudomonas and 17 Acinetobacter spp.), resistant to any of the third-generation cephalosporins, were randomly selected from clinical samples. RESULTS: Of 90 isolates, 64 (71.11%) were tested positive for extended-spectrum ß-lactamase (ESBL) production. Among phenotypically tested ESBL producers, forty isolates were randomly selected for molecular characterization. The prevalence of CTX-M, TEM, and SHV was found to be 57.5%, 15%, and 75%, respectively. Multiplex polymerase chain reaction assay categorized blaCTX-Mgenes into Groups 1 and 26 where Group 1 was present in only 5 isolates and Group 25 was present in rest of the 18 isolates. CONCLUSION: This is among the premier systemic reports from India documenting phenotypic and molecular characterization of CTX-M, TEM, and SHV ß-lactamases in Pseudomonas and Acinetobacter spp. With judicious use of antibiotics and strict infection control procedures, it may be possible to limit the effects of these newer ß-lactamases.

Concurrent occurrence of blaampC families and blaCTX-M genogroups and association with mobile genetic elements ISEcp1, IS26, ISCR1, and sul1-type class 1 integrons in Escherichia coli and Klebsiella pneumoniae isolates originating from India.

Cefoxitin-resistant Escherichia coli (n = 109) and Klebsiella pneumoniae (n = 16) isolates collected from patients in India in 2009 to 2010 were screened for bla(ampC) families and mobilizing elements (ISEcp1, IS26, ISCR1, and sul-1-type class 1 integrons) and their association with bla(ampC) and for the occurrence of class A beta-lactamases (BLs) (CTX-M, TEM, and SHV). The concurrent occurrences of two distinct AmpC families (bla(CIT) and bla(EBC)) and of class A with class C beta-lactamase were observed. All but one of the isolates harboring CTX-M extended-spectrum BLs (ESBLs) were carrying bla(CTX-M) genogroup 1; the remaining isolate carried bla(CTX-M) genogroup 9. The mobilizing elements occurred in different combinations in the study isolates.

Comparative study on occurrence of class A and class C ß -lactamase genes and their co-occurrence in Indian Enterobacteriaceae during years 2009 and 2010.

OBJECTIVE: To determine the occurrence of class A and class C ß-lactamase genes and their co-occurrence in Indian Enterobacteriaceae. METHODS: 52 third generation cephalosporin resistant isolates were phenotypically detected by combination disk method and screened by PCR to identify class A and class C type ß-lactamase genes. RESULTS: Of the 52 isolates, 94.2% (49) were found harboring any of the bla(ESBL(s)). bla(CTX-M), bla(SHV) and bla(TEM) were present in 82.6% (43/52), 59.6% (31/52), and 42.3% (22/52) isolates, respectively. Of the 49 ESBL positive isolates 57.1% (28/49) showed co-occurrence of bla(ampC) with bla(ESBL(s)). On the contrary, the collection from 2009 showed their co-occurrence in 81.4% isolates. CONCLUSIONS: The comparative study shows a downward trend for co-existence of bla(ESBL(s)) with bla(ampC) from 2009 to 2010. Further large scale studies are needed to address the co-occurrence of class A and class C ß-lactamases in India and the resistance trend occurring over a period of time.

bla(CTX-M), bla(TEM), and bla(SHV) in Enterobacteriaceae from North-Indian tertiary hospital: high occurrence of combination genes.

OBJECTIVE: To delineate the frequency of occurrence of bla(CTX-M), bla(TEM), and bla(SHV) in Enterobacteriaceae from North-Indian tertiary hospital. METHODS: A random collection of a subset of 45 Escherichia coli (E. coli) and 28 Klebsiella pneumoniae (K. pneumoniae) that was resistant to a third generation cephalosporin and obtained during 2007-2008 was selected for detailed screening for bla(CTX-M), bla(TEM), and bla(SHV) by monoplex PCRs. The isolates demonstrating the presence of bla(CTX-M) alleles were characterized for the specific CTX-M-genogroup by using a multiplex PCR. RESULTS: Resistance to cefoperazone, ceftazidime, ceftriaxone, cefotaxime, cefoxitin and piperacillin was 100% each in K. pneumoniae isolates, whereas these resistance-rates for E. coli isolates were 93.1%, 83.8%, 91.9%, 93.6%, 97.3% and 97.1%, respectively. Concomitant resistance to aminoglycosides, quinolones and aztreonam was also noticed. Presence of any of the bla genes (bla(CTX-M), bla(TEM), and bla(SHV)) was noticed in a total of 28 (38.4%) isolates of the 73 isolates studied. Many isolates demonstrated occurrence of these genes in various combinations. bla(CTX-M), bla(TEM), and bla(SHV) were noticed in 28.8%, 10.9% and 13.7% isolates, respectively. Multiplex PCR in bla(CTX-M) harboring isolates demonstrated the presence of CTX-M-Genogroup-1 and sequencing for the specific CTX-M-type revealed presence of CTX-M-15 type. RAPD typing showed wide diversity in isolates. CONCLUSIONS: This is amongst the premier report describing the simultaneous occurrence of bla(TEM), bla(SHV), and bla(ampC) in Indian Enterobacteriaceae and that wider dissemination of these genes, as demonstrated by diversity of isolates, raises concern and emphasizes a need for extensive search for the presence of these gene pools in Indian subcontinent.