Surgical site infections by atypical mycobacteria: prevalence and species characterization using MALDI-TOF and molecular LCD chip array.

BACKGROUND: Surgical site infection (SSI) is a post-operative complication of high concern with adverse impact on patient prognosis and public health systems. Recently, SSI pathogens have experienced a change in microbial profile with increasing reports of non-tuberculous mycobacteria (NTM) as important pathogens. AIM: of the study The study aimed to detect the prevalence of NTM among cases with SSIs and describe their species using matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) and PCR-based microarray. METHODS: The study was conducted with 192 pus samples collected from patients with SSI. Mycobacterial investigations were done in the form of Ziehl-Neelsen (ZN) smears for acid-fast bacilli, automated mycobacterial culture to isolate mycobacteria, followed by immunochromatography test to predict NTM. NTM-positive cultures were tested by MALDI -TOF MS and PCR-based microarray to reach species-level identification. RESULTS: Mycobacterial growth was found in 11/192 samples (5.7%) and identified as 4 NTM and 7 M. tuberculosis isolates with prevalence of 2.1% and 3.64%, respectively. The NTM species were described by MALDI-TOF as M. abscessus, M. porcinum, M. bacteremicum, and M. gordonae. Microarray agreed with MALDI-TOF in identifying one isolate (M. abscessus), while two isolates were classified as belonging to broad groups and one isolate failed to be identified. CONCLUSIONS: The prevalence of NTM among SSI was found to be low, yet have to be considered in the diagnosis of mycobacteria. Employing advanced technologies in diagnosis is recommended to guide for appropriate treatment.

Drug resistance and genomic variations among Mycobacterium tuberculosis isolates from The Nile Delta, Egypt.

Tuberculosis is a global public health concern. Earlier reports suggested the emergence of high rates of drug resistant tuberculosis in Egypt. This study included 102 isolates of Mycobacterium tuberculosis collected from two reference laboratories in Cairo and Alexandria. All clinical isolates were sub-cultured on Löwenstein-Jensen medium and analyzed using both BD BACTEC MGIT 960 SIRE Kit and standard diffusion disk assays to identify the antibiotic sensitivity profile. Extracted genomic DNA was subjected to whole genome sequencing (WGS) using Illumina platform. Isolates that belong to lineage 4 represented > 80%, while lineage 3 represented only 11% of the isolates. The percentage of drug resistance for the streptomycin, isoniazid, rifampicin and ethambutol were 31.0, 17.2, 19.5 and 20.7, respectively. Nearly 47.1% of the isolates were sensitive to the four anti-tuberculous drugs, while only one isolate was resistant to all four drugs. In addition, several new and known mutations were identified by WGS. High rates of drug resistance and new mutations were identified in our isolates. Tuberculosis control measures should focus on the spread of mono (S, I, R, E)- and double (S, E)-drug resistant strains present at higher rates throughout the whole Nile Delta, Egypt.

Role of streptococcal infection in the etiopathogenesis of pityriasis lichenoides chronica and the therapeutic efficacy of azithromycin: a randomized controlled trial.

The exact aetiology of pityriasis lichenoides chronica (PLC) remains unknown. While phototherapy is the most investigated therapeutic modality, azithromycin has been used scarcely. The aim of this study is to evaluate the therapeutic efficacy of azithromycin in the treatment of PLC compared to NB-UVB and evaluating the presence of streptococcal infection as a possible etiological factor in PLC patients. The study was designed as a randomised controlled trial. Twenty-four patients with PLC were randomly allocated into either azithromycin (n = 13, standard dose every 10 days) or NB-UVB (n = 11, thrice weekly) groups. End of study (EOS) was either complete clearance of lesions or a maximum of 8 weeks. Therapeutic efficacy was defined as percent reduction in lesions and was calculated for the rash as a whole, erythematous papules alone, and hypopigmented lesions alone and graded into complete, very-good, good, poor or no response. Anti-streptolysin O titre (ASOT), anti-deoxyribonuclease B titre (anti-DNaseB) and throat culture were evaluated at day 0. No significant difference existed between both groups as regards therapeutic efficacy. At EOS, NB-UVB achieved significantly more percent reduction in the extent of hypopigmented lesions and consequently in the rash as a whole (p = 0.001, p = 0.034, respectively). The extent of the rash as a whole was significantly less in the NB-UVB at EOS (p = 0.029, respectively). The effect of NB-UVB on hypopigmented lesions appeared early at week 4 of treatment. Only two patients, one from each group, relapsed during the 3 month follow-up. Evidence of recent streptococcal infection was present in 79% of the cases, mainly in the form of elevated ASOT (94.7%). It was significantly more encountered in young children (< 13 years) (p = 0.03) and was associated with more extent of erythematous papules and consequently with more extent of the rash as a whole (p = 0.05 and p = 0.01, respectively). It did not affect outcome of therapy at EOS. Azithromycin did not show more favorable response in patients with recent streptococcal infection. Therapeutic efficacy of azithromycin is comparable to NB-UVB in treatment of PLC; however, NB-UVB is superior in management of hypopigmented lesions. It is highly suggested that PLC could be a post streptococcal immune mediated disorder.Registration number: ClinicalTrials.gov, NCT03831269.

High Prevalence of VIM, KPC, and NDM Expression among Surgical Site Infection Pathogens in Patients Having Emergency Surgery.

BACKGROUND: The rate of surgical site infection (SSI) in patients who undergo emergency operations is higher than in other patients. Previous studies showed an increasing role of gram- negative pathogens (GNP) in SSI. We aimed to identify GNP causing SSIs after emergency surgery, to characterize the carbapenemase-resistance genes in carbapenem-resistant pathogens (CRPs), and to identify the risk factors for SSI caused by CRP. METHOD: We conducted a one-year prospective study from September 2014 in the Emergency Hospital of Cairo University Hospitals. Surveillance for SSIs was conducted according to the case definitions of the U.S. Centers for Disease Control and Prevention. Clinical specimens from patients suspected of having SSI were collected; pathogens were identified by Bruker matrix-assisted laser desorption ionization time of flight (MALDI-TOF) mass spectometry. Antimicrobial susceptibility was tested by the VITEK-2 and E-test. Carbapenem-resistant GNPs were characterized by multiplex polymerase chain reaction for IMP, VIM, SPM, OXA-48, NDM, KPC, BIC, AIM, GIM, SIM, and DIM. Clinical data for patients with SSI infected with CRP were compared with the non-infected patients for detection of risk factors. RESULTS: Surgical site infection affected 6.7% of patients who had emergency operations, and GNP represented 85% of these pathogens. Carbapenem-resistant pathogens caused 61% of the SSI, including all those caused by Acinetobacter baumannii, 70% of those caused by Pseudomonas aeruginosa, and 67% of those caused by Klebsiella pneumoniae. The PCR revealed that VIM, KPC, and NDM were the most common resistance genes. Risk factors for SSI were previous hospitalization, longer hospital stay, type of surgical incision, and abundant drainage; whereas previous hospitalization and infection by non-enteric environmental GNP were the risk factors for SSI caused by CRP. CONCLUSION: The rate of SSIs caused by CRP was high after emergency surgery. VIM, KPC, and NDM were the most commonly found genes. Prior hospitalization and infection by non-enteric GNP were risk factors, which can be mitigated by eradication of bacterial populations in environmental reservoirs and control of transmission.