ABSTRACT
Integrating conjugative elements (ICEs) are mobile genetic elements that can transfer from the chromosome of a host to the chromosome of a new host through the process of excision, ...conjugation, and integration. Although SXT/R391-related ICEs, originally demonstrated in
Vibrio cholerae
O139 isolates, have become prevalent among
V. cholerae
isolates in Asia, the prevalence of the ICEs among Gram-negative bacteria other than
Vibrio
spp. remains unknown. In addition, SXT/R391-related ICEs carrying genes conferring resistance to extended-spectrum cephalosporins have never been described. Here we carried out a genetic analysis of a cefoxitin-resistant
Proteus mirabilis
clinical isolate, TUM4660, which revealed the presence of a novel SXT/R391-related ICE, ICE
Pmi
Jpn1. ICE
Pmi
Jpn1 had a core genetic structure showing high similarity to that of R391 and carried
xis
and
int
genes completely identical to those of R391, while an IS
10
-mediated composite transposon carrying
bla
CMY-2
was integrated into the ICE. A nucleotide sequence identical to the 3′ part of IS
Ecp1
was located upstream of the
bla
CMY-2
gene, and other genes observed around
bla
CMY-2
in earlier studies were also present. Furthermore, the nucleotide sequences of hot spot 2 and hot spot 4 in ICE
Pmi
Jpn1 showed high similarity to that of hot spot 2 in SXT
MO10
and with a part of the nucleotide sequence found in
P. mirabilis
ATCC 29906, respectively. ICE
Pmi
Jpn1 was successfully transferred to
Escherichia coli
,
Klebsiella pneumoniae
,
Salmonella enterica
serovar Typhimurium, and
Citrobacter koseri
in conjugation experiments. These observations suggest that ICEs may contribute to the dissemination of antimicrobial resistance genes among clinically relevant
Enterobacteriaceae
, which warrants careful observation of the prevalence of ICEs, including SXT/R391-related ICEs.
Ventilator-associated pneumonia (VAP) is an important cause of morbidity and mortality in critical care settings. Acinetobacter has become a leading cause of VAP. In particular, the appearance and ...spread of multidrug-resistant Acinetobacter is of great concern. In this study, we examined the effect of the antioxidant procysteine on Acinetobacter murine pneumonia in hyperoxic conditions in order to simulate VAP.
Acinetobacter was administered intranasally to BALB/c mice kept in hyperoxic conditions. At designated timepoints, bacterial number, cytokine production and histopathological findings in the lungs were examined. The effects of procysteine on survival rates, lung bacterial burdens and the phagocytic activities of alveolar macrophages were evaluated.
Drastic decreases in survival were observed when the infected mice were kept in hyperoxic conditions (P < 0.001). Significant differences in pulmonary bacterial number and neutrophil accumulation were observed between mice kept in hyperoxic or normoxic conditions on day 3. Although all mice infected with Acinetobacter spp. and kept in hyperoxic conditions died by day 3, procysteine treatment significantly improved survival (60% survival on day 7, P < 0.01). Procysteine treatment decreased the lung bacterial burden on days 2 and 3. Finally, improved uptake of FITC-labelled beads by alveolar macrophages from mice treated with procysteine and kept in hyperoxic conditions was noted.
These results suggest that hyperoxia increases mortality in mice with Acinetobacter pneumonia and that procysteine improves survival by increasing the phagocytic activity of alveolar macrophages in mice kept in hyperoxic conditions.
With the development of medicine, the field of clinical laboratory medicine evolves rapidly, and it will be more specialized in the near future. Medical technologists are required to hone their ...skills and knowledge, in order to keep up with the evolution. In recent years, board certifications by several medical societies are considered to indicate the skills of medical technologists. The number of board-certified medical technologists in populated areas such as Tokyo, Kanagawa, Osaka, and Fukuoka is greater than in less populated areas such as Kyusyu and Tohoku. The rate of certified medical technologists among prefectures is the highest in Mie (10.1%), followed by Nagasaki (8.8%). Tokyo, Ishikawa, Kyoto, and Osaka have acquisition rates greater than 7%. In contrast, prefectures of Miyazaki, Kumamoto, Yamanashi, and Akita have low acquisition rates of less than 4%. Being certified is not only an opportunity for personal career advancement, but also a chance to improve the laboratory. More technologists are being certified in our laboratory, and we are encouraging a future increase in their number. However, there are some problems to be overcome. Assignment of competent staff and long-term and premeditated rotation are considered to be important for staff to find the work rewarding, and the laboratory to be trusted by physicians.
We evaluated the efficacy of ethylenediamine-N,N,Na2,Na2-tetraacetic acid, disodium calcium salt (Ca-EDTA), as an inhibitor for New Delhi metallo-I2-lactamase-1 (NDM-1) in vitro antibiotic ...susceptibility and in a mouse model of sepsis caused by Escherichia coli. Ca-EDTA drastically reduced the MICs of carbapenems for all NDM-producing bacteria imipenem (IPM) aO1a2 I14g/ml; meropenem (MEPM) aO1a4 Amg/ml. In the neutropenic murine model of sepsis, the bacterial burden was further reduced by combination therapy using imipenem/cilastatin sodium (IPM/CS) and Ca-EDTA to 2.3 A 103 CFU/liver, compared with 2.9 A 104 CFU/liver for IPM/CS alone. These data demonstrated the possibility of Ca-EDTA for clinical applications. In our understanding, this is the first report examining the effect of Ca-EDTA on a mouse sepsis model caused by NDM-1-producing bacteria.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
We conducted an epidemiological study concerning carbapenem-non-susceptible clinical isolates of Acinetobacter spp. in Japan by molecular procedures including carbapenemase gene identification and ...amplified ribosomal DNA restriction analysis. Among 598 clinically isolated Acinetobacter spp. in 2007, 27 (4.5%) were non-susceptible to carbapenems. Most carbapenem-non-susceptible Acinetobacter baumannii (13/14) belonged to clonal complex (CC) 92, harbored bla OXA-51-like genes, including novel bla OXA-206, downstream of ISAba1, and were recovered mainly from the Kanto region. Carbapenem-non-susceptible A. baumannii CC92 isolates were further divided by pulsed-field gel electrophoresis into two groups, one of which was characterized by the presence of bla OXA-23. One A. baumannii CC276 isolate carried bla IMP-1 and bla OXA-58. Almost all non-baumannii Acinetobacter isolates (12/13), including Acinetobacter pittii (formerly Acinetobacter genomic species 3) and Acinetobacter nosocomialis (formerly Acinetobacter genomic species 13TU), produced IMP-type metallo- Delta *b-lactamases, and were recovered from various regions in Japan. This is the first report describing the nationwide molecular epidemiology of carbapenem-non-susceptible Acinetobacter spp. with genomic species-level identification in Japan.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
PDF
