July Issue 2010

Beta-lactamase production in anaerobic bacteria

Fri, 18 Jun 2010 19:25:02 GMT

Nwaokorie Francisca

Abstract

Anaerobes occur as major components of bacterial flora of the human skin and mucous membranes. They are responsible for a variety of serious and life-threatening
infections. There is a great concern on the treatment of these infections due to the emergence of antibiotic resistance especially to beta-lactam drugs. Resistance to -
lactam drugs take place in anaerobic microbial species mainly by the production of beta-lactamase and this is frequently associated with therapeutic failures. In this
review, the production, genetic determinant, ecological impact and the effects of B-lactamase on therapy is discussed.

Can the HCMV pp65 antigenemia assay completely be replaced by HCMV PCR in monitoring patients after bone marrow transplantation?

Fri, 18 Jun 2010 19:24:05 GMT

Paul R. Lübeck, Hans Wilhelm Doerr, Holger F. Rabenau

Abstract

Background: Human cytomegalovirus (HCMV) is the most frequent viral pathogen in Bone marrow transplant (BMT) patients, where it causes significant morbidity and
mortality. The results of the two most frequently used laboratory assays for the detection of active HCMV infection, the pp65 antigenemia assay and the polymerase chain
reaction (PCR), often differ in BMT patients. Within the context of limited financial resources it is necessary to economize routine laboratory diagnostic procedures. To
evaluate if the pp65 antigenemia assay can be replaced by HCMV-PCR we retrospectively assessed 988 samples from 253 BMT patients without additional information on
the patient’s clinical presentation or therapy.
Results: The mean value of PCR copies rises with the number of pp65-antigen (pp65-Ag) positive cells in the antigenemia assay. However, in the pp65-g 0 the mean value
and the range of the PCR copies are higher than in the pp65-g 1 (pp65-g 0: 1,188 copies, range: 0-200,000 copies; pp65-g 1: 554 copies range: 0-12,900).There is a
statistically significant correlation between the results of the pp65-Ag-assay and quantitative PCR (spearman-correlation: cumulative: 0.49, p= 0.01; pp65-g 2: 0.38, p=
0.01; pp65-g 3: 0.44, p= 0.01). Regarding PCR groups, there is no correlation with the results of the quantitative antigenemia assay. Using any positive PCR result as the
reference, the pp65-Ag-assay showed 59%/77%/60%/76% for sensitivity/specificity/positive predictive value/negative predictive value, respectively and a positive
likelihood ratio of 2.6. These values rose with the number of PCR copies and pp65-positive cells. A highly positive result (pp65-g 3 (>99 cells) or PCR-g 3 (> 9,999
copies/ml)) of either test almost certainly excludes the possibility of a negative result of the other test.
Conclusion: When the pp65-Ag result is greater than 3 positive cells per 400,000 leucocytes, the pp65-Ag-assay and the plasma PCR parallel each other. However, highly
positive PCR results can be obtained in pp65-Ag-assay negative samples. Our results suggest that both assays complement each other and should be used concomitant.

Detection and frequency of mutation in the rpoB gene of Mycobacterium tuberculosis isolates from patients with active Pulmonary Tuberculosis in different regions of

Fri, 18 Jun 2010 19:23:03 GMT

Saeed Zaker Bostanabad, Mehrdad Hashemi, Mohammad Karim Rahimi, Fahimeh Ostadzadeh, Mohammad Bossak, Sajjad Nouri, Shahin Pourazar,
Mostafa Ghalami, Mehdi shekarabei, Hassan Hoseinaei, Vahid Molla Kazemi, Zahra Tayebei, Mozhgan Masoumi, Veronica Slizen, Evgeni Romanovich
Sagalchyk and Leonid Petrovich Titov

Abstract

The aim of this study was to investigate the frequency, location and type of rpoB mutations in Mycobacterium tuberculosis isolated from patients in Tehran City. 145
sputums were collected from suspected tuberculosis patients, 20 Rif-r isolates were identified as Mycobacterium tuberculosis. PCR Amplification and DNA sequencing
methods were performed. 411 bp fragments of rpoB gene were sequenced and mutations in 81 bp regions were analyzed. 20 mutations were identified in 14 RIF-r MBT
(70%). Missense mutations produced 20 types of amino acid substitutions. In 6 RIF-r MBT isolates (30%) no mutations were found in the core region of the rpoB gene.
Most frequent mutations detected from Tehranian strains were in codons 531 and 515. Two alleles in codon 531 and one allele in all codons 526, 515, 510, 566, 490 and
476 were found. In the 6 isolates were identified 2 mutation in different codons and 8 strains harboured single mutations in codons. In this study, has been investigated
the significance of mutations in the rpoB gene, its correlation with genotype and phenotype agents and high level of resistance to rifampicin in 14 isolates of M.
tuberculosis collected from patients with active pulmonary tuberculosis from different geographic regions of Tehran.

Rapid detection of novel (swine origin) H1N1 influenza- A virus from a variable nucleotide in the matrix gene

Fri, 18 Jun 2010 19:21:36 GMT

Alfaresi, M.S.

Abstract

The novel H1N1 subtype influenza A virus, which was generated by reassortment between two known circulating swine influenza strains, has been renamed human
pandemic influenza A virus, or novel H1N1. Novel H1N1 originated in Mexico and the United States, and has now spread to 126 countries. Based on the publicly released
sequences of novel H1N1, we and others identified a 174G>A variant in the matrix gene, which could be used to discriminate the new pandemic virus from other human
seasonal influenza A/H1N1 viruses. Because the presence of the 174 G>A sequence variant in the matrix gene may be useful for diagnosing novel H1N1, we developed
and evaluated a real-time RT-PCR assay to detect the variant in specimens. Our method can provide a much-needed rapid validation of other real-time PCR assays,
particularly in the case of influenza A viruses isolated from humans that are difficult to subtype.

Regulation of host innate immunity by hepatitis C virus: crosstalk between hepatocyte and NK/DC

Fri, 18 Jun 2010 19:20:41 GMT

Sung-Jae Park, Young S. Hahn

Abstract

Hepatitis C virus (HCV) infection in humans is remarkably efficient in establishing viral persistence, leading to the development of liver cirrhosis and hepatocellular
carcinoma. CD8+ T cells are involved in controlling HCV infection; but, in chronic HCV patients, severe CD4+ and CD8+ T cell dysfunction has been observed. This
suggests that HCV may employ numerous mechanisms to counteract or possibly suppress the host T cell responses. The primary site of HCV replication occurs within
hepatocytes in the liver. As a result of liver enodothelial cells perforated by fenestrations, parenchymal cells (hepatocytes) are not separated by a basal membrane, and
thereby HCV-infected hepatocytes are extensively capable of interacting with innate immune cells including NK, DC. Recent studies reveal that the function of NK and DC
function is significantly impaired in chronic HCV patients. Given a critical role of NK and DC in limiting HCV replication at the early phase of viral infection, it is likely that
HCV-infected hepatocytes might be responsible for impairing NK and DC function by enhancing the expression of immunoregulatory molecules (either soluble or cell
surface). Thus, this impairment of innate immunity attributes to the failure of generating effective T cell responses to clear HCV infection. In this article, we will review
studies highlighting the regulation of innate immunity by HCV and crosstalk between hepatocytes and NK/DC in the hepatic environment.

Sero-prevalence of toxoplasmosis among patients visiting the Korle-Bu Teaching Hospital,

Fri, 18 Jun 2010 19:19:46 GMT

Ayeh-Kumi P. F, Opoku A.G, Kwakye-Nuako G, Dayie TKD, Asmah RH, Obeng Nkrumah A, Lartey M, Sagoe A, Attipoe MI, Osafo KA, Kretchy JP

Abstract
Toxoplasmosis is a disease caused by the intracellular protozoan parasite Toxoplasma gondii. It affects up to about one third of the human population worldwide.
Toxoplasmosis in neonates and immunocompromised patients can lead to severe disease and even death. However, there is a lack in knowledge concerning the extent of
the toxoplasmosis problem in Ghana. In the present study, we determined the seroprevalence of Toxoplasma gondii infection among patients visiting visiting Korle-Bu
Teaching Hospital using the enzyme-linked immunosorbent assay (ELISA). Of the 165 patients studied, IgG antibodies were found in 32.7% (95% CI: 25.0 – 39.3%). IgM
and IgA seroprevalence were 29.7% (95% CI: 22.2 – 36.1%) respectively. There was significant association between seroprevalence of Toxoplasma gondii antibodies and
gender (P< 0.05), with the male sex being at increased risk of Toxoplasma gondii seropositivity (OR ,95% CI: IgG - 2.78,1.34-5.82; IgM - 3.31, 1.57-6.981; IgA – 3.31,
1.57-6.981). No significant association (P> 0.05) was observed between the age groups and seroprevalence of Toxoplasma gondii antibodies. Ourstudy reveals an overall
high seroprevalence of Toxoplasmosis among patients visit ing the Korle-Bu Teaching Hospital. Public campaigns may be necessary to educate the Ghanaians about ways
to minimise exposure Toxoplasma gondii.

Idiopathic lethal granuloma of the midline facial tissues

Fri, 18 Jun 2010 19:18:22 GMT

Troncoso Alcides, Maria Laura Rossi, Bava Amadeo Javier

Abstract

Granuloma faciale (GF) is a rare chronic inflammatory dermatosis usually appearing only on the face, associated with high morbidity and mortality. Exact etiology is
uncertain. We present an illustrative case of GF. A 32 year-old female patient was admitted at the infectious diseases service of the School of Medicine Buenos Aires
University for presenting progressive destruction of face, nose, paranasal sinuses, palate, oral and para-oral strctures. The intra-oral examination revealed the features of
GF. A biopsy at that time showed GF. GF has an unknown etiology, but possible predisposing factors include actinic exposure, radiation, trauma, allergy, or an Arthus-like
reaction.

The burden of malaria among under five children: Finding from Makurdi city, north

Fri, 18 Jun 2010 19:17:23 GMT

Jombo Gta, Mbaawuaga Em, Anongu St, Egah Dz, Enenebeaku Mno, Peters Ej, Utsalo Sj,
Okwori Ee , Odey F

Abstract

Background
As Africa marks the ninth year of roll back malaria programme, several of her endemic communities still appear heavily tied down by the disease. This study was
therefore carried out to ascertain the burden of Falciparum parasitaemia among children in Makurdi city.

Methods
The study was hospital based; children attending different Primary Healthcare Centres (PHCs) for their routine immunization were recruited for the study. Information
about the children such as: age, sex, and utilization of insecticide treated bed nets (ITNs) were obtained using structured questionnaire. Body temperatures were
measured using paediatric thermometers. Thick and thin arterial blood films were stained using Giemsa’s stain and examined microscopically for malaria parasites.
Packed cell volume (PCV) was measured using microhaematocrit tubes with haematocrit machine.

Results
The incidence of Plasmodium falciparum parasitaemia was 32.3% (162/502); those aged 0-12 months, (8.7%,4/46) and those aged 49-60 months, (50.0%, 30/60) had
the lowest and the highest rate of infections respectively. Ownership and utilization of insecticide treated bed nets (ITNs) was recorded among 25.0% (128/502) of the
children; 28.0% (140/502) used untreated bed nets, while 47.0% (234/502) had no access to any bed net. Fever was recorded among 1.8% (9/502) of the children of
which 88.9% of them had malaria parasites in their blood (P<0.05). Anaemia was recorded in 85.9% (139/162) and 15.0% (45/302) of those with malaria parasites in
their blood and those without respectively, (P<0.001).

Conclusion
Malaria is still a major problem in Makurdi city, more efforts should be directed, among others, towards the provision of Insecticide Treated bed Nets so as to hasten the
actualization of the goal of “Roll Back Malaria” initiative.

In vitro-antibacterial activity and phytochemical profiles of Cinnamomum tamala (Tejpat)

Fri, 18 Jun 2010 19:15:37 GMT

Ajay K. Mishra, B. K. Singh, and Abhay K. Pandey

Abstract

Plant extracts and essential oils have been known since antiquity to possess notable biological activity, including antibacterial, antifungal and antiviral properties. There is
a growing interest in the use of natural products in the human food and animal feed industries as consumer resistance to synthetic additives increases. A base for the
development of a medicine, a natural blue print for the development of new drugs or phytomedicine to be used for the treatment of disease. Plant extracts have great
potential as antimicrobial compounds against several pathogenic microorganism which cause infectious disease and resistant towards synthetic drugs. The aim of this
study was to examine the antibacterial effects of leaf extracts and oil of Cinnamomum tamala against major pathogenic bacteria. Phytochemical analysis has shown the
presence of various antimicrobial components as natural antibiotics. The antibacterial and Minimum Inhibitory Disc Concentration ware evaluated by the Kirby Baure Paper
Method. Minimum Inhibitory Disc Concentration and Minimum Inhibitory Concentration of oil and extracts against various bacteria range from 0.90-2.25 µg/disc and 0.60-
2.40 mg/ml. Acetone and aqueous fraction of extracts showed strongest inhibitory potential. According to results Cinnamomum tamala (Ct) leaf oil and extracts can be
considered as potential antimicrobial agent for the treatment of various infectious diseases.