Polymerase Chain Reaction targeting insertion sequence IS6110 for the diagnosis of pulmonary tuberculosis among Sudanese children and young adults

This study was carried out in Khartoum State during the period from January 2011 to December 2013 to improve the rate of detection of Mycobacterium tuberculosis (MTB) in children with symptoms of tuberculosis (TB) infection using different conventional and advanced diagnostic techniques. One hundred and ninety-seven specimens of gastric lavage and sputum were collected from different hospitals in Khartoum State, including Elbolok Hospital, Jafar Ibn Owf Hospital, Elasha'ab Teaching Hospital, Soba University Hospital and Academy Charity Hospital. All children participating in the study were subjected to the Mantoux test after obtaining appropriate consent injected by 5 tuberculin units of tuberculin purified protein derivative, and the results were recorded after three days. Specimens were decontaminated and inoculated on Lowenstein–Jensen media according to the modified Petroff's method. Two smears were prepared and stained by Ziehl–Neelsen stain and Auramine fluorescent dye; bacterial DNA was extracted from each specimen by using phenol chloroform method, and then the Polymerase Chain Reaction technique was adopted to detect Insertion Sequence IS6110 gene of MTB in these specimens. This study showed that the positive results for TST, ZN, Auramine, Culture and PCR were 86 (43.7%), 16 (8.1%), 22 (11.2%), 32 (16.2%) and 35(17.8%), respectively. The study concluded that the PCR technique is the most sensitive and specific technique for a quick identification of MTB in gastric lavage and sputum from children who are unable to expectorate a good quality sputum sample or who are diagnosed as negative using conventional diagnostic methods

Challenges in diagnosing tuberculosis in children: a comparative study from Sudan

Objectives: The diagnosis of tuberculosis (TB) in children is challenging due to insufficient specimen material and the scarcity of bacilli in specimens. This study aimed to evaluate methods for diagnosing TB in children in Sudan. Methods: Patients (N = 197) were subjected to the tuberculin skin test (TST). Gastric lavage or sputum specimens were then collected, processed, and cultured as per standard procedures. Results: Culture on Löwenstein–Jensen medium, the reference standard, revealed growth in 16.2% of the specimens. Comparative analysis showed that 43.7% were positive for the TST (sensitivity 100%, specificity 67.3%), 8.1% were positive by Ziehl–Neelsen stain (sensitivity 43.8%, specificity 98.8%), 11.2% by auramine stain (sensitivity 56.3%, specificity 98.8%), and 17.8% were positive for PCR amplification of the IS6110 sequence (sensitivity 100%, specificity 98.8%). Conclusions: It is concluded that whilst TST and IS6110 achieved 100% sensitivity based on the reference standard of culture, the latter was more specific. The TST is recommended for routine diagnosis and the use of PCR for particular cases, depending on the facilities and the urgency

Absence of the mecA Gene in Methicillin Resistant Staphylococcus aureus Isolated from Different Clinical Specimens in Shendi City, Sudan

Absolute dependence on mecA gene as the defining standard in determining the resistance of S. aureus to methicillin became the subject of distrust by many researchers. The present study aimed to determine the frequency of mecA gene in methicillin resistant S. aureus (MRSA) isolates using polymerase chain reaction and to correlate its presence to conventional method. In this regard, two hundred S. aureus isolates were collected from patients with different diseases attending different hospitals in Shandi City, Sudan. Phenotypic Kirby-Bauer method confirmed the existence of methicillin resistant S. aureus in 61.5% of the subjected isolates with MICs ranging from 4 g/mL to 256 g/mL when using E-test. However, when amplifying a 310 bp fragment of the mecA gene by PCR, twelve out of the 123 MRSA isolates (9.8%) were mecA negative, whereas all the 77 methicillin sensitive S. aureus (MSSA) were mecA negative. In conclusion, this study drew attention to the credibility of the mecA gene and its usefulness in the detection of all MRSA strains without referring to the traditional methods. Hence, it is highly recommended to consider alternative mechanisms for -lactam resistance that may compete with mecA gene in the emergence of MRSA phenomenon in the community

Absence of the mecA Gene in Methicillin Resistant Staphylococcus aureus Isolated from Different Clinical Specimens in Shendi City, Sudan

Absolute dependence on mecA gene as the defining standard in determining the resistance of S. aureus to methicillin became the subject of distrust by many researchers. The present study aimed to determine the frequency of mecA gene in methicillin resistant S. aureus (MRSA) isolates using polymerase chain reaction and to correlate its presence to conventional method. In this regard, two hundred S. aureus isolates were collected from patients with different diseases attending different hospitals in Shandi City, Sudan. Phenotypic Kirby-Bauer method confirmed the existence of methicillin resistant S. aureus in 61.5% of the subjected isolates with MICs ranging from 4 μg/mL to 256 μg/mL when using E-test. However, when amplifying a 310 bp fragment of the mecA gene by PCR, twelve out of the 123 MRSA isolates (9.8%) were mecA negative, whereas all the 77 methicillin sensitive S. aureus (MSSA) were mecA negative. In conclusion, this study drew attention to the credibility of the mecA gene and its usefulness in the detection of all MRSA strains without referring to the traditional methods. Hence, it is highly recommended to consider alternative mechanisms for β-lactam resistance that may compete with mecA gene in the emergence of MRSA phenomenon in the community

Epidemiological trends of cutaneous leishmaniasis in Al-Madinah Al-Munawarah Province, Western Region of Saudi Arabia

Objective: To investigate the epidemiological trends of cutaneous leishmaniasis (CL) in Al-Madinah Al-Munawarah, western region of KSA. Materials and Methods: Four hundred and sixty-seven parasitologically confirmed CL cases attending Al-Meeqat Hospital, Al-Madinah, during 2012–2015, were included in this study. Results: Both Saudi and non-Saudi nationals were infected, with the highest infection rate being among Saudis (68.7%). Males were more affected than females as 86.9% of the total CL cases were males. Moreover, CL was prevalent in all age groups with higher frequency among young adults and adolescents (23.1% and 22.7%, respectively). Interestingly, almost all the patients in the adolescent and child age groups were Saudis (96.2% and 93.5%, respectively). Considering geographical distribution, the highest percentage of the cases (40.5%) were from the northern parts of Al-Madinah province while the eastern parts reported the least infection rate (7.3%). Few cases (2.5%) were supposed to encounter the infection abroad. Additionally, the frequency of infection was found to follow a seasonal distribution. Regarding treatment, pentostam, ketoconazole, or cryotherapy were the treatment options usually used. Conclusion: CL is prevalent in Al-Madinah Al-Munawarah area and new foci are being introduced. Thus, detailed studies with large surveillances regarding vector and reservoir hosts in and around the area are needed

Isolation and Identification of Streptomyces spp. from Desert and Savanna Soils in Sudan

The purpose of this study was to investigate streptomycete populations in desert and savanna ecozones in Sudan and to identify species based on 16S rRNA gene sequences. A total of 49 different Streptomyces phenotypes (22 from sites representing the desert and semi-desert ecozone; 27 representing the savanna ecozone) have been included in the study. The isolates were characterized phenotypically and confirmed using 16S rRNA gene sequence analysis. The two ecozones showed both similarities and uniqueness in the types of isolates. The shared species were in cluster 1 (Streptomyces (S.) werraensis), cluster 2 (Streptomyces sp.), cluster 3 (S. griseomycini-like), and cluster 7 (S. rochei). The desert ecozone revealed unique species in cluster 9 (Streptomyces sp.) and cluster 10 (S. griseomycini). Whereas, the savanna ecozone revealed unique species in cluster 4 (Streptomyces sp.), cluster 5 (S. albogriseolus/ S. griseoincarnatus), cluster 6 (S. djakartensis), and cluster 8 (Streptomyces sp.). Streptomycetes are widely distributed in both desert and the savanna ecozones and many of these require full descriptions. Extending knowledge on Streptomyces communities and their dynamics in different ecological zones and their potential antibiotic production is needed