Characteristics of Carbapenem-Resistant Pseudomonas aeruginosa Strains in Patients with Ventilator-Associated Pneumonia in Intensive Care Units

Abstract

The aim of this study was to determine the characteristics of carbapenem-resistant Pseudomonas aeruginosa (P. aeruginosa) strains and 5-year changes in resistance in a tertiary university hospital. Material and Methods. The study included 90 and 101 randomly selected P. aeruginosa strains serotyped in 2003 and 2008, respectively. The standardized disk diffusion test and E-test were used to determine resistance to antibiotics. P. aeruginosa strains were considered to have high-level resistance if a minimum inhibitory concentration (MIC) for imipenem or meropenem was >32 μg/mL. To identify serogroups, sera containing specific antibodies against O group antigens of P. aeruginosa were used. P. aeruginosa isolates resistant to imipenem or/and meropenem were screened for metallo-β-lactamase (MBL) production by using the MBL E-test. Results. Comparison of the changes in resistance of P. aeruginosa strains to carbapenems within the 5-year period revealed that the level of resistance to imipenem increased. In 2003, 53.3% of P. aeruginosa strains were found to be highly resistant to imipenem, while in 2008, this percentage increased to 87.8% (P=0.01). The prevalence of MBL-producing strains increased from 15.8% in 2003 to 61.9% in 2008 (P<0.001). In 2003 and 2008, carbapenem-resistant P. aeruginosa strains were more often resistant to ciprofloxacin and gentamicin than carbapenem-sensitive strains. In 2008, carbapenem- resistant strains additionally were more often resistant to ceftazidime, cefepime, aztreonam, piperacillin, and amikacin than carbapenem-sensitive strains. MBL-producing P. aeruginosa strains belonged more often to the O:11 serogroup than MBL-non-producing strains (51.7% vs. 34.3%, P<0.05). A greater percentage of non-MBL-producing strains had low MICs against ciprofloxacin and amikacin as compared with MBL-producing strains. Conclusions. The results of our study emphasize the need to restrict the spread of O:11 serogroup P. aeruginosa strains and usage of carbapenems to treat infections with P. aeruginosa in the intensive care units of our hospital

Prevalence and Antibiogram Patterns of Pseudomonas aeruginosa Isolated from Two Wastewater Treatment Plants in Aden Governorate-Yemen

“…This result is disagree with a local study in Sana'a-Yemen that reported (5.4%) of isolate from non-clinical sources were resistant to Imipenem [21], and disagree with a study conducted in Egypt that reported (46%) of environmental P. aeruginosa isolates were resistant to Meropenem [17]. Furthermore, in agreement to our finding, a study in Lithuania revealed that resistant to Carbapenems has increased dramatically for Imipenem from (53.3%) in 2003 to (87.8%) in 2005, which is online with our finding [22].…”

Comparison of Epidemiological and Antibiotic Susceptibility Pattern of Metallo-Beta-Lactamase-Positive and Metallo-Beta-Lactamase-Negative Strains of Pseudomonas Aeruginosa

“…reported the prevalence of MBL-producing P. aeruginosa as 15.8%, in 2003, which increased to 61.9%, in 2008, resulting in a 46% rise in only a five-year period. [ 9 ] These results clearly demonstrate the increasing burden of MBL strains in the same hospital setup, although the rate of increment varies widely. Interestingly, in our setup the increase in the MBL-positive strain from 2002 to 2012 has not been very drastic (12 to 16.57%) in contrast to the study by Vitkauskiene et al .…”

“…Interestingly, in our setup the increase in the MBL-positive strain from 2002 to 2012 has not been very drastic (12 to 16.57%) in contrast to the study by Vitkauskiene et al . [ 9 ] In India, the incidence of MBL production in P. aeruginosa has been reported to be 10-30% from various clinical specimens across the country. [ 10 ] A similar prevalence rate of MBL-producing strains of P. aeruginosa has been observed in studies conducted by Hemalatha V et al .…”

Emergence of antibiotic-resistant extremophiles (AREs)

“…Table 1 summarizes few AREs that have shown resistance to MIC of various antimicrobial agents. It has also been found that the presence of metallo-b-lactamase has shown to have a higher MIC in P. aeruginosa than the non metallo-b-lactamase producing strains in patients with pneumonia in intensive care units (Vitkauskiene et al 2011). P. aeruginosa has been found to be resistant to MICs of meziocillin (75 mg/L), ceftazidime (30 mg/L), and cefepime (30 mg/L) in patients with lower respiratory tract infections acquired in intensive care unit (Ozer et al 2012).…”