Quantification of hematozoa in blood smears

Ten thin blood smears from mourning doves (Zenaida macroura) infected with Haemoproteus maccallumi were examined by each of two observers using identical techniques and microscopy in an attempt to delineate the factors necessary to provide an accurate estimate of the number of parasites/n erythrocytes. The number of erythrocytes examined must be actually counted, not estimated from extrapolated partial counts or from the number of fields of view examined. Doubling the number of erythrocytes counted (1) decreased the overdispersed frequency distribution patterns in only 25% of the replicate counts for numbers of H. maccallumi/100 erythrocytes for a series of 2,000 versus 4,000 erythrocytes counted; and (2) did not significantly increase the accuracy for determining parasite intensities. Thus, the number of erythrocytes that must be counted to determine parasite intensities could be considerably reduced from the 10,000 or 20,000 estimated for most studies, and still provide an accurate determination of the number of parasites/n erythrocytes in datasets collected from hosts with moderate to high levels of parasitemia. This resulted in a decreased amount of time expended by the observer on each blood smear examined. With two equivalently trained individuals, differences between observers examining the same blood smears were minimal. This study suggests an approach by which a more standardized methodology for quantifying blood parasite intensities could be developed.     

Fecal mutagens and Bacteroides fragilis levels in the feces of dimethylhydrazine-treated rats: influence of diet

In a study designed to investigate the effects of dietary synergisms on 1,2-dimethylhydrazine (DMH)-induced rat colon carcinogenesis, fecal pellets were examined for the presence of direct-acting fecal mutagens and levels of Bacteroides fragilis group organisms. Intraperitoneal injections of DMH at 10 mg/kg were given for 16 weeks (weeks 3-18) to 160 male F344 rats consuming 4 supplemental dietary factors in all possible combinations. The dietary factors examined were wheat bran (15%), cholesterol (1%), beef tallow (18%) and indole-3-carbinol (IC) (0.1%). Feces were collected 3, 10, 17, 24 and 31 weeks after commencing the dietary treatments and dichloromethane extracts were assayed using the Salmonella typhimurium TA100 without metabolic activation. The numbers of B. fragilis group organisms were enumerated in feces collected at the same time. Most feces samples were negative for mutagens but extracts from weeks 17-31 showed a significant mutagenic response from the IC factor in the diet. The fecal levels of B. fragilis were significantly increased by the inclusion of cholesterol in the diets. The B. fragilis counts and fecal mutagen production were not correlated (r = 0.09), although species of the B. fragilis group have been implicated in the production on human fecal mutagens.     

Factors affecting the initiation of mini-rhizomes from Trillium erectum and T. grandiflorum tissues in vitro

Leaf and stem explants of Trillium grandiflorum and T. erectum produced mini-rhizomes (MRs) in vitro which gave rise to shoots and roots. The apical portion of the stem and the basal portion of the leaves were the most effective explants from these tissues, while stem tissue was more responsive than leaf tissue. The best response with both species was observed on half-strength MS basal medium supplemented with cytokinin and auxin. T. erectum was more responsive than T. grandiflorum overall, and in some cases produced MRs in the absence of growth regulators. Culture at 21°C appeared to stimulate growth from T. grandiflorum tissues, compared with controls at 27°C, whereas the outgrowth of shoots from MRs was inhibited in both species at 21°C. In vitro production of MRs could provide a more rapid, alternative propagation method for these species than traditional methods.     

Rallinyssus sorae sp. n. (Acari: Dermanyssidae: rhinonyssinae) from the nasal passages of the sora, Porzana carolina (Aves: Rallidae)

Rallinyssus sorae sp. n. is described from the nasal turbinates of the sora, Porzana carolina, collected in Maryland and Ohio. The new species is most similar to Rallinyssus verheyeni Fain but differs in number of setae on the female ventral opisthosoma, structure of the fixed and movable digits of the male and female chelicerae, chaetotaxy of legs I to IV, and presence of a sternal plate in the male. The taxonomy and host-parasite relationships of the various species of Rallinyssus are discussed.     

Trauma History and Depression Predict Incomplete Adherence to Antiretroviral Therapies in a Low Income Country

Background

As antiretroviral therapy (ART) for HIV becomes increasingly available in low and middle income countries (LMICs), understanding reasons for lack of adherence is critical to stemming the tide of infections and improving health. Understanding the effect of psychosocial experiences and mental health symptomatology on ART adherence can help maximize the benefit of expanded ART programs by indicating types of services, which could be offered in combination with HIV care.

Methodology

The Coping with HIV/AIDS in Tanzania (CHAT) study is a longitudinal cohort study in the Kilimanjaro Region that included randomly selected HIV-infected (HIV+) participants from two local hospital-based HIV clinics and four free-standing voluntary HIV counselling and testing sites. Baseline data were collected in 2008 and 2009; this paper used data from 36 month follow-up interviews (N = 468). Regression analyses were used to predict factors associated with incomplete self-reported adherence to ART.

Results

Incomplete ART adherence was significantly more likely to be reported amongst participants who experienced a greater number of childhood traumatic events: sexual abuse prior to puberty and the death in childhood of an immediate family member not from suicide or homicide were significantly more likely in the non-adherent group and other negative childhood events trended toward being more likely. Those with incomplete adherence had higher depressive symptom severity and post-traumatic stress disorder (PTSD). In multivariable analyses, childhood trauma, depression, and financial sacrifice remained associated with incomplete adherence.

Discussion

This is the first study to examine the effect of childhood trauma, depression and PTSD on HIV medication adherence in a low income country facing a significant burden of HIV. Allocating spending on HIV/AIDS toward integrating mental health services with HIV care is essential to the creation of systems that enhance medication adherence and maximize the potential of expanded antiretroviral access to improve health and reduce new infections.     

Ectoparasites of the swift fox in northwestern Texas

Ectoparasites were collected from chemically immobilized swift foxes (Vulpes velox) in the Texas Panhandle (USA). Three species of fleas (Pulex irritans, Dactylopsylla percernis, and Euhoplopsyllus affinis) and one species of tick (Ixodes sculptus) were found. Pulex irritans was the only abundant ectoparasite; it occurred on all 23 foxes brushed in 1999-2000 and all but one of 34 hosts examined in 2000-01. Otherwise, this swift fox population had a depauperate ectoparasite fauna; the remainder of the ectoparasites only occurred on a few (< or =5%) of the hosts. Because of previous taxonomic confusion between P. irritans and the closely related P. simulans, the zoogeographic distribution of these two species in many areas of western North America needs to be verified. Apparently, only the human flea P. irritans occurs on wild canids in the Texas Panhandle. However, there are previous records of P. simulans on other carnivores in western and central Texas. Some of these specimens were reexamined, and their identifications were reconfirmed. Also, the recent literature on the controversial taxonomic status of these two flea species is reviewed. The male terminal aedeagal sexual apparatus is the only means currently available to separate P. irritans and P. simulans.     

Helminths of the ocelot from southern Texas

In the USA, the ocelot (Leopardus pardalis) is a highly endangered felid found only in a few remaining vestiges of native thornshrub brushland in the Lower Rio Grande Valley (LRGV) of extreme southern Texas. From 1987-1998, carcasses of 15 adult ocelots that died of vehicular accidents or natural causes were examined for helminths. All cats had 1-8 (mean = 3) helminth species. All were infected with 1-101 (mean +/- SE = 32 +/- 7) Toxascaris leonina. Other helminths from these ocelots were Alaria marcianae, Brachylaima sp., Mesocestoides lineatus, Taenia rileyi, Oncicola canis, Dirofilaria immitis, Physaloptera rara, Ancylostoma tubaeformae, Cylicospirura chevreuxi, Vogeloides felis, and Metathelazia californica. Additionally, two cats had scarring of the aorta with lesions typical of those caused by Spriocerca lupi, although larval nematodes were not seen. A clinal variation in size of nearly three orders of magnitude was noted in the diplostomatid trematodes in the small intestine of one adult male ocelot. Despite the differences in size, all specimens appeared morphologically identical and were regarded as A. marcianae. Helminth prevalences and abundances, including those of potentially pathogenic species like D. immitis, were low. Although a single heartworm infection may have contributed to the death of one ocelot, helminth infections in general seemed to be of no great consequence to this endangered ocelot population. The helminth fauna of ocelots in the LRGV is reflective of that from wild felids in general; all have been reported previously from the bobcat (Lynx rufus) and mountain lion (Puma concolor) elsewhere in Texas.     

Beta-Lactamase Repressor BlaI Modulates Staphylococcus aureus Cathelicidin Antimicrobial Peptide Resistance and Virulence

BlaI is a repressor of BlaZ, the beta-lactamase responsible for penicillin resistance in Staphylococcus aureus. Through screening a transposon library in S. aureus Newman for susceptibility to cathelicidin antimicrobial peptide, we discovered BlaI as a novel cathelicidin resistance factor. Additionally, through integrational mutagenesis in S. aureus Newman and MRSA Sanger 252 strains, we confirmed the role of BlaI in resistance to human and murine cathelidicin and showed that it contributes to virulence in human whole blood and murine infection models. We further demonstrated that BlaI could be a target for innate immune-based antimicrobial therapies; by removing BlaI through subinhibitory concentrations of 6-aminopenicillanic acid, we were able to sensitize S. aureus to LL-37 killing.