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C Needham

Publications and source records attributed to C Needham.

7 recordsLinked to original sources
PubMed1998

Epidemiology of soil-transmitted nematode infections in Ha Nam Province, Vietnam.

Baseline epidemiological data are presented from a parasitological survey conducted in Thuy Loi commune, Ha Nam province, Vietnam; a farming community where night soil is routinely used as fertilizer for crops. 177 households were visited and 543 individuals (aged 1-88 years) recruited to the study. Helminth infection intensity was assessed by Kato-Katz to determine the density of parasite eggs per gram of stool (epg). Ascaris lumbricoides, Trichuris trichiura and hookworm infections were the only species detected. 83% of individuals were infected with A. lumbricoides (mean epg = 11,971), 94% with T. trichiura (mean epg = 793) and 59% with hookworm (mean epg = 302). Age-dependent patterns of infection prevalence and intensity were similar for A. lumbricoides and T. trichiura, but markedly different for hookworm infection. Similarly, age-dependency in the k-values for the three infections was due to covariance with the respective mean intensities with age rather than to independent age effects, with similar patterns for A. lumbricoides and T. trichiura, and a different pattern for hookworm. Three major conclusions can be drawn from the multiple-species analyses: There is positive interaction between A. lumbricoides and T. trichiura infections; high-intensity A. lumbricoides infections are significantly associated with high-intensity T. trichiura infections; and there is positive interaction between these two species such that infection intensity of A. lumbricoides is higher in individuals with concurrent T. trichiura infection than in individuals without and vice versa.

Adolescent↗
PubMed1995

The staphylococcal insertion sequence IS257 is active.

The plasmid pJ3356 confers high-level mupirocin resistance on a strain of Staphylococcus aureus isolated from a hospital. The plasmid also carries two copies of IS257. Recombination of an IS257-containing plasmid conferring erythromycin resistance, pOX7-IS, into either of the IS257s of pJ3356 has been observed. The co-integration of pJ3356 and a small plasmid, pOX7, is also reported and involves duplication of one of the IS257s from pJ3356 together with 8 bp of pOX7 at the site of integration. Thus IS257 has been shown to be an active mobile genetic element.

Base Sequence↗
PubMed1994

An investigation of plasmids from Staphylococcus aureus that mediate resistance to mupirocin and tetracycline.

Plasmids conferring mupirocin resistance were prepared from isolates of Staphylococcus aureus obtained from four patients in the same ward. The plasmids are related and in all of them the gene conferring mupirocin resistance (mupA) is flanked by copies of IS257 in direct repeat. In two plasmids mupA and IS257 have been duplicated and in one of these plasmids (pJ3358) a small pT181-like plasmid conferring tetracycline resistance is present flanked by copies of IS257. Filter mating with a strain containing pJ3358 as donor and selection on tetracycline sometimes resulted in transfer of the pT181-like plasmid containing a copy of IS257. Analysis showed that the pT181-like plasmid with the insertion of IS257 is present in high copy number and that the IS257 element is inserted in the copy number control region of the plasmid.

Base Sequence↗
PubMed1987

Sensititre autoreader for same-day breakpoint broth microdilution susceptibility testing of members of the family Enterobacteriaceae.

The Sensititre Autoreader system is an instrument-assisted broth microdilution susceptibility test procedure based on the detection of fluorogenic growth substrate metabolism by test bacteria with different concentrations of antimicrobial agents. In the current investigation, this system was assessed as a means for predicting the in vitro activity of 17 antimicrobial agents versus numerous species of the family Enterobacteriaceae and Pseudomonas aeruginosa by using a breakpoint broth microdilution test format. Same-day and overnight determinations of susceptibility were made with the Sensititre Autoreader system, and in both cases, the results were compared with those obtained with a manual overnight breakpoint broth microdilution susceptibility test. Among a total of 6,086 organism-antimicrobial agent comparisons with Enterobacteriaceae, concordance was noted between the results of the same-day Autoreader system and the manual overnight test in 94.4% of cases. The same-day Autoreader results with members of the Enterobacteriaceae other than Proteus spp. were determined after 4 h of incubation; with Proteus spp. the same-day Autoreader results were determined after 5 h of incubation. When the Enterobacteriaceae Autoreader results were determined after 18 h of incubation, concordance was noted in 97.2% of comparisons. Among a total of 1,377 organism-antimicrobial agent comparisons with P. aeruginosa after 18 h of incubation, agreement of results from the manual overnight test and the Autoreader system was achieved in 92.2% of cases.

Anti-Bacterial Agents↗
PubMed1986

Failure to detect ampicillin-resistant, non-beta-lactamase-producing Haemophilus influenzae by standard disk susceptibility testing.

We questioned whether the apparent rarity of ampicillin-resistant, non-beta-lactamase-producing (NBLP) Haemophilus influenzae was due to failure of detection. We identified ampicillin-resistant and ampicillin-susceptible H. influenzae by the agar dilution technique, using 10(5)- and 10(3)-CFU inocula. We compared the disk susceptibility of 18 ampicillin-resistant NBLP strains, 13 ampicillin-resistant, beta-lactamase-producing strains, and 10 ampicillin-susceptible strains by using standard 10- and 2-micrograms ampicillin disks on two different media. We also investigated the possibility that disks containing 10 micrograms of clavulanic acid and 2 micrograms of ampicillin could be used to distinguish between the two ampicillin-resistant populations. Using the disk containing 2 micrograms of ampicillin, we correctly differentiated all the ampicillin-resistant isolates from the ampicillin-susceptible isolates on both media (a zone diameter of less than or equal to 15 mm was considered resistant). In contrast, the 10-micrograms ampicillin disk failed to detect 44% (8 of 18) of the ampicillin-resistant NBLP strains (a zone diameter of less than or equal to 19 mm was considered resistant). The MIC of ampicillin with the 10(3)-CFU inoculum correlated better with zone diameters than with the 10(5)-CFU inoculum. A difference in zone diameters of greater than or equal to 8 mm between the disk containing 10 micrograms of clavulanic acid and 2 micrograms of ampicillin and the disk containing only 2 micrograms of ampicillin correctly identified all beta-lactamase-producing strains. We conclude that the 2-micrograms ampicillin disk tests more readily identify ampicillin resistance in H. influenzae than do the 10-micrograms ampicillin disk tests. Future investigation should determine whether this in vitro resistance correlates with clinical treatment failures.

Ampicillin↗