Prevalence, haemolytic and haemagglutination activities and antibiotic susceptibility profiles of Campylobacter spp. isolated from human diarrhoeal stools in Vhembe District, South Africa

Campylobacter species are increasingly being recognized as agents of gastroenteritis worldwide. However, data on the pathogenic characteristics of the organism isolated in rural communities in South Africa are lacking. In this study, the prevalence of Campylobacter spp. from diarrhoeal stools, haemolytic and haemagglutinating activities of the isolates, and antibiotic susceptibility profiles, including minimum inhibitory concentration (MIC) patterns to different antibiotics, were determined using the standard microbiological techniques. Campylobacter spp. were isolated from individuals of all age-groups; however, the infection rate was higher among individuals aged less than two years (30.4%). Of 115 Campylobacter strains isolated, polymerase chain reaction (PCR) analysis indicated that 98 (85%) were C. jejuni, while 17 (15%) were C. coli. Seventy-one (62%) of the strains showed haemolysis on human blood, and 80% agglutinated human blood, whereas 22.6% were beta-lactamase-positive. Resistance to antimicrobials, such as erythromycin, ciprofloxacin, vancomycin, and fusidic acid, was high. Increased resistance to macrolide and quinolone antibiotics poses major risks for treatment failure. Haemolytic and haemagglutinating activities may be useful in preliminary characterization of pathogenic strains in settings where Campylobacter-associated infections are common.     

Prevalence, pathogenesis, antibiotic susceptibility profiles, and in-vitro activity of selected medicinal plants against Aeromonas isolates from stool samples of patients in the Venda region of South Africa

The prevalence, pathogenic indices, such as haemolytic and haemagglutinating activities, antibiograms, and in-vitro activities of local medicinal plants against Aeromonas isolates in Vhembe district of Limpopo province, South Africa, were studied using standard microbiological methods. In total, 309 diarrhoeic stool samples were collected from patients attending five health centres in the region during December 2004-May 2005. Aeromonas species were identified using the API 20E system. The haemagglutinating and haemolytic activities of isolates on human, sheep, pig and chicken red blood cells were investigated. Antibiotic susceptibility profiles of the isolates to several antibiotics and in-vitro activity of local medicinal plants were also ascertained using previously-reported schemes. Results showed that 104 (33.6%) of the 309 samples were positive for Aeromonas species, of which 89 (85.6%) were Aeromonas hydrophila, 12 (11.5%) A. sobria, and three (2.9%) A. caviae. All strains of A. hydrophila and A. caviae produced haemolysis on sheep blood, while eight of the 12 A. sobria strains were haemolytic on sheep blood. The haemolytic activities of the isolates were variable on other red blood cells tested. High level of resistance was observed to amoxicillin and ampicillin, followed by cefuroxime (79%), chloramphenicol (74%), and erythromycin (65%). The carbapenems were the most active drugs with only 7% resistance to meropenem and 11% to imipenem. About 12% of the isolates were resistant to ciprofloxacin. The extracts of three of seven medicinal plants tested showed inhibitory activity against all Aeromonas isolates; these included acetone and hexane extracts of Pterocarpus angolensis, Syzygium cordatum, and Zornia milneana. The results suggest a high prevalence of Aeromonas species in the region. The isolates demonstrated multiple resistant profiles to different antibiotics tested. Some local medicinal plants were inhibitory to Aeromonas isolates, indicating a potential role in the management of Aeromonas-related infections. Structural elucidation of the active components may pave the way for the discovery of candidate templates for eventual drug design. Most isolates possessed important virulence characteristics based on their haemolytic and haemagglutinating ability. However, the genetic characterization of the isolates will further confirm their pathogenicity and the origin of multiple antibiotic resistance.     

Murine macrophage chemokine receptor CCR2 plays a crucial role in macrophage recruitment and regulated inflammation in wound healing

Macrophages play a critical role in the establishment of a regulated inflammatory response following tissue injury. Following injury, CCR2⁺ monocytes are recruited from peripheral blood to wound tissue, and direct the initiation and resolution of inflammation that is essential for tissue repair. In pathologic states where chronic inflammation prevents healing, macrophages fail to transition to a reparative phenotype. Using a murine model of cutaneous wound healing, we found that CCR2‐deficient mice (CCR2^?/?) demonstrate significantly impaired wound healing at all time points postinjury. Flow cytometry analysis of wounds from CCR2^?/? and WT mice revealed a significant decrease in inflammatory, Ly6C^Hi recruited monocyte/macrophages in CCR2^?/? wounds. We further show that wound macrophage inflammatory cytokine production is decreased in CCR2^?/? wounds. Adoptive transfer of mT/mG monocyte/macrophages into CCR2^+/+ and CCR2^?/? mice demonstrated that labeled cells on days 2 and 4 traveled to wounds in both CCR2^+/+ and CCR2^?/? mice. Further, adoptive transfer of monocyte/macrophages from WT mice restored normal healing, likely through a restored inflammatory response in the CCR2‐deficient mice. Taken together, these data suggest that CCR2 plays a critical role in the recruitment and inflammatory response following injury, and that wound repair may be therapeutically manipulated through modulation of CCR2.     

Intratracheal instillation of perfluorocarbon rescued mice with primary pulmonary hypoplasia

The aim of this study was to investigate the effect of perfluorocarbon on the respiratory status of newborn mice with pulmonary hypoplasia without diaphragmatic defects, following intrauterine exposure to nitrofen. Three groups of newborn mice were compared: pups exposed to nitrofen antenatally without (group A) or with (group B) perfluorocarbon treatment and pups not exposed to nitrofen as a control (group C). Respiratory evaluation was performed by scoring, pressure-volume analysis, and histological examination. At 40 minutes after birth, the survival rates in groups A, B, and C were 51%, 94%, and 95%, respectively. The clinical scores of group B mice at 40 minutes were significantly better than those of group A mice in which pulmonary hypoplasia was induced. In group B, the hysteresis ratio was significantly higher than that in group A, and lung histology showed a significant increase in airspace. An immunohistochemical examination showed that perfluorocarbon did not alter the expression of mature surfactant protein B and surfactant proprotein C. This study demonstrated that treatment with perfluorocarbon was useful in stabilizing critically ill mice with primary pulmonary hypoplasia during the early phase of therapy.     

Factors predisposing to poorly differentiated hepatocellular carcinoma and its recurrence

BACKGROUND/AIMS: We investigated the clinical factors predisposing moderately or poorly differentiated hepatocellular carcinoma and analyzed which clinical and histological factors are associated with poorly differentiated hepatocellular carcinoma (HCC) recurrence. METHODOLOGY: Percutaneous fine-needle biopsy was taken from the liver tumor of 191 consecutive patients between January 1994 and September 1996. The histological degree of differentiation of hepatocellular carcinoma at the first time of initial treatment and at the time of second recurrence was classified according to the criteria of Edmondson and Steiner. RESULTS: At the time of the first therapy, 86 patients, 81, 24, and 0 patients had liver tumors classified as Edmondson (Ed), 1, 2, 3, and 4, respectively. The prognosis of patients with Ed-3/4 HCC was worse than and the tumor sizes were larger than that of Ed-1/2 HCC patients. Of the 167 patients classified as Ed-1/2 at the time of first therapy, HCC recurred in 95 of the patients during the mean follow-up period of 3.4 years. Multivariate analysis revealed that only tumor size (P=0.035) and TACE therapy (P=0.0009) were independently significant factors in predicting future Ed-3/4 or multiple HCC recurrence. CONCLUSIONS: Tumor size and TACE therapy were clinical predisposing factors for Ed-3/4 or multiple HCC recurrences.     

Early detection of haemobilia associated with percutaneous ethanol injection for hepatocellular carcinoma

OBJECTIVE: Haemobilia often results from iatrogenic injury caused by therapeutic procedures. The objective of this study was to evaluate the efficacy of early diagnosis of haemobilia based on ultrasonography in patients with hepatocellular carcinoma undergoing percutaneous ethanol injection. PATIENTS AND METHODS: A combination retrospective and prospective study on the early detection of haemobilia caused by percutaneous ethanol injection was conducted on 365 patients in 1995-1996. The retrospective study reviewed the clinical, laboratory and imaging data of 172 patients who had undergone ethanol injection therapy in 1995. The results showed that ultrasonographic changes in the gallbladder, namely the rapid appearance of echogenic material in the gallbladder lumen, are a useful early sign of haemobilia. Based on the results of the retrospective study, a prospective study on the early detection of haemobilia was carried out in 1996. In the prospective study, percutaneous ethanol injection was halted as soon as haemobilia was detected. RESULTS: The incidence of haemobilia in the prospective group (3.6%) was not different from that in the retrospective group (4.7%). However, the mean duration between percutaneous ethanol injection and diagnosis of haemobilia was only 0.3 +/- 0.2 days in the prospective group, compared with 2.8 +/- 2.1 days in the retrospective group (P < 0.001), and the mean duration of jaundice in the prospective group (4.3 days) was significantly shorter than in the retrospective group (40.0 days) (P< 0.05). CONCLUSION: Early diagnosis of haemobilia based on ultrasonographic findings of the gallbladder lumen effectively reduces the severity of haemobilia-related complications due to immediate interruption of the interventional procedure.