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Factors Associated with Relative Rates of Antibiotic Resistance in Pseudomonas aeruginosa Isolates Tested in Clinical Laboratories in the United States from 1999 to 2002. Robert K. Flamm, 2004.For the period from 1999 to 2002 in the United States, the in vitro susceptibilities of 52,637 Pseudomonas aeruginosa isolates to 10 antimicrobial agents were evaluated . The isolates were from 29 laboratories, 11 of which participated in The Surveillance Network for four consecutive years . Isolates were collected from adult patients (  18 years of age) in intensive care units (ICU), non-ICU inpatients, nursing home patients, and outpatients; data were analyzed to evaluate factors, such as year of isolation, patient age group, isolate specimen source, and patient type (hospitalized patients [ICU, non-ICU, or nursing home] or outpatients) . Rates of resistance for the 4-year period were highest for isolates from patients in ICU and 18- to 39-year-old patients and for isolates from the lower respiratory tract . Resistance decreased with age . Resistance was lowest in isolates from outpatients, in isolates from
70-year-old patients, and from specimens from the upper respiratory tract . Multidrug resistance (MDR) (resistance to three or more antimicrobial agents) accounted for 24.9% of all isolates . The MDR rate was highest in isolates from patients in nursing homes (29.9%) and ICU (29.5%) .
In Vivo Immobilization of Fusion Proteins on Bioplastics by the Novel Tag BioF. Cristina Moldes, 2004.A new protein immobilization and purification system has been developed based on the use of polyhydroxyalkanoates (PHAs, or bioplastics), which are biodegradable polymers accumulated as reserve granules in the cytoplasm of certain bacteria . The N-terminal domain of the PhaF phasin (a PHA-granule-associated protein) from Pseudomonas putida GPo1 was used as a polypeptide tag (BioF) to anchor fusion proteins to PHAs . This tag provides a novel way to immobilize proteins in vivo by using bioplastics as supports . The granules carrying the BioF fusion proteins can be isolated by a simple centrifugation step and used directly for some applications . Moreover, when required, a practically pure preparation of the soluble BioF fusion protein can be obtained by a mild detergent treatment of the granule . The efficiency of this system has been demonstrated by constructing two BioF fusion products, including a functional BioF-ß-galactosidase . This is the first example of an active bioplastic consisting of a biodegradable matrix carrying an active enzyme . Functional Analysis of the Signal Recognition Particle in Escherichia coli by Characterization of a Temperature-Sensitive ffh Mutant. Sei-Kyoung Park, 2002.The Ffh protein of Escherichia coli is a 48-kDa polypeptide that is homologous to the SRP54 subunit of the eukaryotic signal recognition particle (SRP) . Efforts to understand the function of Ffh in bacteria have depended largely on the use of E . coli strains that allow depletion of the wild-type gene product . As an alternative approach to studying Ffh, a temperature-sensitive ffh mutant was isolated . The ffh-10(Ts) mutation results in two amino acid changes in conserved regions of the Ffh protein, and characterization of the mutant revealed that the cells rapidly lose viability at the nonpermissive temperature of 42°C as well as show reduced growth at the permissive temperature of 30°C . While the ffh mutant is defective in insertion of inner membrane proteins, the export of proteins with cleavable signal sequences is not impaired . The mutant also shows elevated expression of heat shock proteins and accumulates insoluble proteins, especially at 42°C . It was further observed that the temperature sensitivity of the ffh mutant was suppressed by overproduction of 4.5S RNA, the RNA component of the bacterial SRP, by stabilizing the thermolabile protein . Collectively, these results are consistent with a model in which Ffh is required only for localization of proteins integral to the cytoplasmic membrane and suggest new genetic approaches to the study of how the structure of the SRP contributes to its function .
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