Iranian Journal of Microbiology

Increased incidence of methicillin resistant Staphylococcus aureus and methicillin resistant Staphylococcus epidermidis in the skin and nasal carriage among healthcare workers and inanimate hospital surfaces after the COVID-19 pandemic

2024-11-12T06:31:49+0330

Background and Objectives: Healthcare workers in hospitals are exposed to infectious diseases that occur in the hospital making them a source of infection for the patients. It is interfaced as cross-contamination agents for MRSA and MR-CoNS, and preventive measures need to be adapted accordingly. The study aimed to assess Methicillin-Resistant Staphylococcus (MRS) on the skin and nasal cavities of healthcare workers (HCWs) and identifying isolates to the species level.
Materials and Methods: Swab samples were cultured on mannitol salt agar (MSA) to obtain MRS and determine their ability to produce coagulase. Their susceptibility to antibiotics were determined by agar screening and disk diffusion methods and further identification was done at the species level.
Results: The highest percentage of methicillin resistant coagulase positive Staphylococci (MRCoPS) was reported among skins of male HCWs, (71.4%) were identified as MRSA. The highest levels of methicillin resistant coagulase negative Staphylococci (MRCoNS) were mainly detected in both nasal cavities, (75%) were identified as MRSE. MRSA was reported from doctors (p-value 0.033), whereas the highest incidence of MRSE was obtained from the nurses (p-value 0.048).
Conclusion: This study highlighted that incidence of MRSA was mainly detected in doctors and MRCoNS in both nasal cavities. The highest percentage of MRCoNS was recovered from the patients’ room followed by the reception table. Moreover, vancomycin is suggested to be highly effective in managing and controlling S. aureus, MRSA- and MRSE related infections.

MIC trends of vancomycin and teicoplanin among methicillin resistant CoNS isolates from new born blood cultures in a tertiary care centre in Southern India

2024-11-12T06:31:47+0330

Background and Objectives: Coagulase-negative-Staphylococci (CoNS) are important etiological agent of bacteraemia in newborn babies. Methicillin resistant CoNS infections have only limited treatment options. The antimicrobial susceptibility pattern of Methicillin Resistant CoNS isolates from newborn blood cultures was studied with special reference to MICs of Vancomycin and Teicoplanin.
Materials and Methods: The study population included Methicillin Resistant Coagulase Negative Staphylococcal isolates (MRCoNS) from newborn blood cultures, during a one-year period. Minimum inhibitory concentration (MIC) of Vancomycin and Teicoplanin in Methicillin resistant CoNS isolates was determined by macrobroth dilution method as per CLSI guidelines and by automated methods.
Results: Coagulase Negative Staphylococci were the etiological agent in 73.7% (n-56) cases of neonatal bacteremia. Methicillin resistance in newborn CoNS was found to be 58.9%. All the MRCoNS isolates had vancomycin and teicoplanin MICs in the susceptible range. There were MRCoNS isolates with MICs in the upper limit of susceptible range for both vancomycin and teicoplanin, which can result in poor clinical response.
Conclusion: Continuous large scale multi-centre surveillance studies with special attention to study the MIC pattern of the high-end anti-MRSA agents like vancomycin, teicoplanin, linezolid are to be carried out. This will help the clinicians to judiciously prescribe the antibiotics, which is very essential for antimicrobial stewardship.

Prevalence, antimicrobial resistance, virulence gene distribution and SCCmec typing of methicillin-resistant Staphylococcus aureus isolated from raw milk and dairy products

2024-11-12T06:31:46+0330

Background and Objectives: Researchers have focused on Staphylococcus aureus because it is transmitted through food, such as milk and dairy products, and causes human diseases. Prevalence, antimicrobial resistance, presence, and distribution of methicillin-resistant S. aureus (MRSA) virulence genes isolated from raw milk and dairy products were evaluated.
Materials and Methods: 300 samples of dairy products were collected from Shahrekord, Iran. S. aureus was identified using biochemical tests and screened for sensitivity to 13 antibiotics to identify resistance genes. In addition, SCCmec typing was performed.
Results: Out of 300, S. aureus was found in 82 samples. Raw milk had the highest contamination with S. aureus (60 of 82), followed by cheese (15 of 82), and butter (7 of 82). At least one resistance gene was present in every isolate of S. aureus. Virulence factors and enterotoxin-coding genes, such as sea, seb, sec, and sed were highly distributed.
Conclusion: The results of this study revealed the presence of toxin-producing MRSA strains in raw milk and dairy products. MRSA in dairy farms is an important risk factor for the spread of staphylococcal infections; therefore, further studies are needed to find strategies for controlling the presence of S. aureus, especially MRSA, in dairy products.

Effect of chitosan nanogels loaded with vancomycin and gamma interferon on TNF-α gene expression in macrophage cell line activated with methicillin-resistant Staphylococcus aureus (MRSA)

2024-11-12T06:31:45+0330

Background and Objectives: Staphylococcus aureus is an opportunistic pathogen that frequently leads to asymptomatic infections. Methicillin-resistant strains (MRSA) pose a significant threat as they are resistant to most commonly used antibiotics, complicating treatment efforts. This study aimed to develop chitosan nanogels loaded with vancomycin and IFN-γ and to assess the expression of the TNF-α gene in a cell line infected with MRSA.
Materials and Methods: Following the synthesis and confirmation of the chitosan nanogels, vancomycin and IFN-γ were incorporated into these nanogels. The synthesis was validated using DLS, FTIR, TEM, and SEM. Subsequently, the antibacterial efficacy of the nanogels was assessed. Finally, four groups of cell lines were designed: control, MRSA, chitosan nanogels and IFN-γ-vancomycin chitosan nanogels. After infection of the groups (except control) with MRSA, 5 μg/mL of nanogels, and nanogels (drug and IFN-γ) were added to groups 3 and 4, respectively. Then the expression of TNF-α gene in each group was analyzed by RT-PCR at 6 and 24 hours.
Results: At pH 6.5 and 7.4, the MIC of 1 μg/mL was obtained for free vancomycin, whereas that of IFN-γ-vancomycin nanogels at both pHs was respectively 8 and 64 μg/mL. The IC50 of chitosan nanogels and nanogels loaded with vancomycin-IFN-γ on RAW264.7 cells were 2.37 and 4.15 μg/mL in 24 hours, respectively. In group 4 in comparison to the MRSA group, TNF-α expression decreased significantly following 24 hours.
Conclusion: Loading of vancomycin and IFN-γ in the chitosan nanogel can reduce TNF-α gene expression on MRSA infected cell lines.

Streptococcus dysgalactiae subsp.-equisimilis as an emerging secondary pathogen in leprosy foot ulcers

2024-11-12T06:31:43+0330

Background and Objectives: Leprosy foot ulcers (LFU) tend to become chronic due to secondary bacterial infections, leading to subsequent disfigurement and disability. Treatment modality for infected plantar ulcers thus so far is majorly based on conventional approach of empirical antibacterial therapy. However, this approach tends to overlook unconventional pathogens which are likely to be present in the LFU.
Materials and Methods: Twenty-six leprosy patients (17 males and 9 females) who had completed multidrug therapy (MDT) and those are suffering from foot ulcer were included. Using sterile cotton swabs, two wound swabs were collected, of these; one for bacterial culture and another for NGS (Next Generation Sequencing).
Results: Out of 26 samples tested on conventional bacterial culture, Streptococcus spp. (50%) was predominant organism. On NGS, 09/26 (34.61%) showed Streptococcus-dysgalactiae-subsp.-equisimilis-GGS 12 as the most abundant single organism, along with some unknown and unclassified organisms; 03/26 (11.5%) were Arcanobacterium-haemolyticum-DSM-20595 alone and 02/26 (7.69%) were Streptococcus-pyogenes alone. A combination of Arcanobacterium-haemolyticum-DSM-20595 and Streptococcus-dysgalactiae-subsp.-equisimilis-GGS 124 was found in nine (34.61%) specimens.
Conclusion: Polymicrobial infection with conventional and unconventional pathogenic bacteria is another notable finding suggesting appropriate interventions. The study findings also reiterate the need for understanding the polymicrobial infections and their role in the clinical progression of the LFU.

Growth response of Vibrio cholerae O1 and V. cholerae non O1/non O139 strains to algae extracts from stream water in far north Cameroon

2024-11-12T06:31:43+0330

Background and Objectives: Vibrio cholerae O1 or non O1/non O139 is found in water ecosystems where it colonizes phytoplankton and has different lifestyle. This study aimed to investigate the impact of some algae extracts on the survival/growth of both V. cholerae strains.
Materials and Methods: Algae extracts consisting of three fractions, F1 containing chlorophyll-a, F2 containing chlorophyll-b, and F3 containing carotenoids, and raw extract (RAE) were obtained from the algal bloom collected in the Kaliao stream (Maroua, Cameroon). The survival and growth of V. cholerae O1 and V. cholerae non O1/non O139, in microcosms consisting of sterile saline with these extracts and peptone (PEP) respectively added at concentrations of 0.01, 0.05 and 0.1 mg/L, and 50/50 mixtures F1+F2, F2+F3, and F2+PEP at a concentration 0.05 mg/L, were compared during a 24h experiment.
Results: The microcosms F2 and RAE did not support the growth of O1 strain; V. cholerae non O1/non O139 count in all algae extract microcosms ranging from 3.97 log (CFU/mL) to 5.2 log (CFU/mL). In all PEP microcosms, the counts of both strains reached an uncountable value. Microcosms F1+F2 and F2+F3 supported the growth of V. cholerae O1 and V. cholerae non-O1/nonO139 strains.
Conclusion: The algae compounds showed strain-specific effect on the growth of V. cholerae.

Serological and bacterial prevalence of Brucella spp. in suspected patients: a risk factor analysis in North Khorasan, Iran

2024-11-18T04:05:58+0330

Background and Objectives: Brucellosis, a zoonotic bacterial disease caused by Brucella, affects humans and domestic animals, leading to significant economic loss. This study examined suspected cases in North Khorasan, Iran, to understand the prevalence of infection and its characteristics in this region.
Materials and Methods: Blood specimens were collected from 200 patients suspected of brucellosis after obtaining informed consent. Serum samples were tested using RBPT, Wright, and 2-ME agglutination tests. Blood samples were cultured on Brucella agar, and positive cultures underwent biotyping and PCR assays. A questionnaire identified correlated risk factors.
Results: RBPT, Wright, and 2-ME tests showed 25% brucellosis seroprevalence in symptomatic patients. In contrast, the prevalence was 2.5% among those with positive blood cultures. Notably, all culture-positive patients were also serologically positive, with titers exceeding 1:320 in Wright and 2-ME tests. Most positive cases were in people in their 30s, with B. melitensis biovar 1 identified as the causative agent, and the results were confirmed by multiplex PCR. Significant risk factors include contact with livestock and consumption of raw milk (P < 0.0001).
Conclusion: The findings highlighted the importance of comprehensive diagnostic approaches for accurate identification of brucellosis. Furthermore, education regarding close contact with animals and pasteurization of dairy products is essential for controlling human brucellosis.

Gut microbiota and graft-versus-host disease in hematopoietic stem cell transplant patients

2024-11-12T06:31:40+0330

Background and Objectives: Graft-versus-host disease (GvHD) frequently complicates hematopoietic stem cell transplantation (HSCT). Emerging evidence suggests a correlation between gut microbiota and GvHD risk. This study aims to elucidate the microbiota profiles in HSCT patients before and after transplantation and their association with GvHD.
Materials and Methods: This study, conducted from December 2022 to December 2023, involved the collection of 15 stool samples from HSCT patients. Bacterial content was quantified using real-time PCR, while interleukin-6 levels were assessed via ELISA.
Results: Among the 15 participants (8 male, 7 female), 9 underwent allogeneic HSCT (allo-HSCT) and 6 received autologous HSCT. In the aGvHD group, there was a significant reduction in the abundance of Bacteroides and Bifidobacterium compared to those without aGvHD. Additionally, declines were observed in Clostridium and Firmicutes populations. The genus Blautia also showed reduced prevalence in the aGvHD group, whereas no significant differences were noted in the uncomplicated group. ELISA analysis revealed that interleukin-6 levels remained within the normal range (30-960 pg/ml) with no significant elevation in the aGvHD group.
Conclusion: The study highlights a notable association between alterations in gut microbiota, specifically reductions in certain bacterial populations and the development of aGvHD following allo-HSCT.

The heterologous expression of novel recombinant protein composed of HN and F moieties of Newcastle disease virus and immunogenicity evaluation in mouse model

2024-11-12T06:31:39+0330

Background and Objectives: The rapid spread of Newcastle disease (ND), driven by extensive commercial exchange in the poultry industry, necessitates urgent preventive measures. Although effective vaccines against the Newcastle disease virus (NDV) have been used since 1940, recent outbreaks and the limitations of current vaccines highlight the need for improved solutions. Advances in synthetic biology, reverse vaccinology, molecular biology, and recombinant DNA technology over the past 20 years have led to the development of recombinant vaccines, which offer enhanced protection and broader immunogenic coverage against NDV. This study aimed to express the immunogenic domains of Hemagglutinin Neuraminidase (HN) and Fusion (F) glycoproteins, linked to the heat-labile enterotoxin B subunit (LTB) bio-adjuvant, to develop an effective and reliable recombinant vaccine for NDV.
Materials and Methods: In this study, the L(HN)2F protein, composed of the LTB bio-adjuvant and the immunogenic regions of the doubled Hemagglutinin Neuraminidase (HN-HN) and Fusion (F) epitope, was expressed in Escherichia coli. Subcutaneous injection was used to evaluate the humoral immune response in mice and the result was compared with B1 vaccine.
Results: The induction of strong humoral immune responses proved the strong immunoreactivity of the recombinant protein.
Conclusion: The IgG elicited by the recombinant proteins was comparable to that of the commercial B1 vaccine against NDV, indicating its potential as a viable candidate for further development and evaluation as a recombinant vaccine against NDV.

New nano-chemotherapeutic chitosans-garlic oil-antibiotics against diabetic foot virulent Proteus spp.

2024-11-12T06:31:38+0330

Background and Objectives: Diabetes foot ulcer is recognized to have a major side effect that raises the risk of amputation. Diabetic ulcer bacterial infections caused by virulent and resistant bacteria like Proteus mirabilis lead to serious wounds that are incurable with conventional medications.
Materials and Methods: In this study, we evaluated the antibacterial activity of a natural product nanochitosan - garlic oil against ten diabetic foot isolates of Proteus mirabilis. Various chitosans (Crab (CScr) - shrimp (CSsh) - squilla (CSsq)) in nano form were prepared and coated with garlic oil (GO). GC-MS analysis was carried out to determine the main components of the essential garlic oil. The physicochemical properties of GO-NCSsq were analyzed using dynamic light scattering (DLS), zeta potentials (ZP) and subsequently scan electron microscope (SEM). Additionally, the minimum inhibitory concentration (MIC) and fraction inhibitory concentration index (FICI) were determined.
Results: GC-MS analysis revealed the presence of major palmitic fatty acid. (GO) loaded on nanochitosan squilla (NCSsq) showed high activity. Although SEM showed lower nano-size, average size of the GO-NCSsq was 330.8 nm by DLS and its zeta potential formulation was +39.6 mV. The final formulation represented by GO-NCSsq + Pipercillin (Pi) inhibited the virulence factor of P. mirabilis and reduced the MIC value (p-value > 0.001). Moreover, the killing time at 9 h was found to be significantly higher for GO-NCSsq + pipercillin (Pi) against P. mirabilis.
Conclusion: In order to manage diabetic foot infections, GO-NCSsq is a legitimate antibacterial agent that can be coupled with other antibiotics.

Prevalence of JC polyomavirus among rheumatoid arthritis and systemic lupus erythematosus patients and its correlation with vitamin D levels

2024-11-12T06:31:37+0330

Background and Objectives: Vitamin D deficiency in viral infection associated with autoimmune diseases is well documented. This study assessed the prevalence of JC virus in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), and its correlation with vitamin D level.
Materials and Methods: Serum and urine samples were collected from 50 patients with RA and SLE. DNA was extracted and subjected to PCR test. Positive PCR products were sequenced, phylogenetic tree was constructed to determine the JC virus genotype. The patient’s vitamin D level was evaluated.
Results: Of 50 patients, 19 (38%) were diagnosed as RA, and 31 (62%) were identified as SLE. JC virus DNA was detected in 17 (34%) patients’ urine samples including 5 (26.3%) RA and 12 (38.7%) SLE cases. JC virus DNA was detected 2 (4%) in patients’ serum samples (one RA. and one SLE). JC virus genotype 3A was dominant. Interestingly, the SLE patients with positive JC virus showed lowered vitamin D compared to patients with negative JC virus (P<0.005).
Conclusion: Given the high rate of JC virus, DNA detection and susceptibility of patients for PML development, it is recommended that detection of JC virus DNA and vitamin D level should be implemented for patients with RA/SLE prior to treatment.

Adenovirus-5 and adenovirus-37 seropositivity in obese patients

2024-11-12T06:31:36+0330

Background and Objectives: Obesity is a major health issue linked to conditions like diabetes, hypertension, and hyperlipidemia. Infectobesity suggests that certain microorganisms may contribute to obesity. Human adenovirus serotypes, particularly Human adenovirus type-36 (HAdV-36), Human adenovirus type-5 (HAdV-5), and Human adenovirus type-37 (HAdV-37), are thought to influence body fat regulation. This study investigates the relationship between Immunoglobulin G (IgG) positivity for HAdV-5 and HAdV-37 and obesity, aiming to provide data on the infectious etiology of obesity.
Materials and Methods: Blood samples separated into serums from obese (BMI ≥30) and non-obese (BMI 18.5-25) individuals were tested for HAdV-5 and HAdV-37 seropositivity using ELISA kits and seropositivity rates between the groups were compared.
Results: HAdV-37 antibody positivity was significantly higher in obese patients (39/48) compared to the control group (24/42) (p=0.011). For HAdV-5, antibody positivity was similar in both groups (26 individuals each) with no significant difference (p=0.461). No significant gender-related differences were found for either serotype.
Conclusion: The study suggests HAdV-37 may be associated with obesity, while no such relationship was found for HAdV-5. There was no gender association for either serotype. These results align with existing literature on HAdV-37, but further research is needed to confirm the link between adenoviruses and obesity and explore potential treatment options.

Molecular detection of Epstein-Barr virus in paraffin-embedded tissue samples of patients suffering gastric cancer in Ahvaz, Iran: a case-control study

2024-11-12T06:31:34+0330

Background and Objectives: Gastric cancer (GC) is the third most common cause of cancer-related mortality. Epstein-Barr virus (EBV) is associated with several human tumors. The present research was performed to investigate the prevalence of EBV-associated gastric cancer (EBVaGC) among Iranian patients.
Materials and Methods: Seventy cases of gastric cancer and 30 cases of gastric ulcer, all preserved in formalin-fixed paraffin-embedded (FFPE), were examined in a case-control study conducted between 2011 and 2018. The specimens underwent analysis to detect the presence of the EBV genome using a Nested-PCR method targeting EBNA1. Subsequently, samples testing positive for the EBNA1 underwent further testing for the presence of the EBER gene using PCR. Finally, Positive samples were subjected to sequencing.
Results: Five out of 70 cases (7%) were found to be positive for EBV based on EBNA1 testing, while all EBNA1 positive samples were negative for EBER. Notably, EBV was not detected in patients with gastric ulcer. The mean age of EBV-positive gastric carcinomas pateints was 64.5 years. Within this group, 60% were male and 40% were female. A higher prevalence of EBV association was observed in diffuse-type cases, with 60% (3 out of 24) testing positive, compared to intestinal-type cases where 40% (2 out of 46) were EBV-positive. Most cases of EBVaGC belonged to grade Ⅰ.
Conclusion: This research demonstrates a low prevalence of EBVaGC in Iran. Discrepancies in EBVaGC occurrence among countries could be attributed to epidemiological variables and dietary practices. A comprehensive studies will provide significant contributions to understanding of its etiology.

Biofilm formation and drug susceptibility of biofilm Candida spp. clinically isolated from nasopharyngeal cancer patients in Vietnam

2024-11-12T06:31:33+0330

Background and Objectives: The biofilm formation has been widely recognized as one of the main mechanisms of antimicrobial resistance development in microorganisms. However, few studies are focusing on this phenomenon in Candida spp. in clinical settings, especially on immuno-compromised patients.
Materials and Methods: In this study, both the rate of biofilm formation in those patients and its drug susceptibility in initial and mature biofilm were assessed using crystal violet assay and dilution method.
Results: The results demonstrated that the biofilm formation rate was similar between albicans and non-albicans Candida. However, the biofilm formation capacity was more pronounced in non-albicans Candida, especially, C. glabrata. As expected, there was a significant relationship between biofilm formation and drug resistance. In addition, our study reconfirmed that the age of high concentration of antifungal agents only affected Candida before its biofilm formation regardless of its biofilm formation capacity. In the contrary, once the biofilm was formed even elevated drug concentrations did not show sufficient efficacy, highlighting a need for high dosage at the early stage of treatment for those patients.
Conclusion: The results of this study highlighted the importance of using appropriate antifungal agents for Candida treatment before the formation of biofilm.

Is routine screening for Candida auris necessary in ICU?

2024-11-12T06:31:32+0330

Background and Objectives: The capability to cause invasive infection, multi-drug resistance, and health care-associated outbreaks of Candida auris have made it a pathogen of great concern. Estimating how many patients in our intensive care unit had C. auris colonization and what characteristics put patients at risk for having Candida spp. colonization were the primary goals of the study.
Materials and Methods: Swabs from axilla and groin were collected from 229 patients getting admitted to the ICU. Samples were inoculated into CHROMagar^TM Candida Plus medium. Colonies presumptively identified as C. auris by the presence of light blue with blue halo and were confirmed by VITEK-2.
Results: Our study showed that only one patient was colonized with C. auris. A total of 47 (20.5%) patients were colonized with Candida spp., of which Candida parapislosis was the predominant organism. History of antibiotic use and cerebrovascular accident were independent risk factors in Candida colonization.
Conclusion: Active screening for Candida auris in all patients is not required in our hospital as the prevalence was very low and not cost-effective. Therefore we plan to modify our screening strategy and use risk factors based surveillance strategy as it may serve as an ideal strategy.

Robust contact tracing and screening needed for leprosy control and protection of vulnerable children

2024-11-12T06:31:31+0330

Leprosy in children is considered as an indicator of active disease transmission in the community. We report about a seven-year-old male from Telangana, India, with anesthetic skin lesions and familial leprosy history. Clinical examination revealed multiple, dry, scaly, hypopigmented, well-defined, raised punched out anesthetic skin lesions all over the body with both ulnar nerves enlarged. On clinical and laboratory examination, the child was diagnosed with borderline-borderline (BB), multibacillary (MB) leprosy, and Type-1 reaction. The child received a weight-adjusted MB multidrug therapy regimen and corticosteroids for type-1 reactions. This case emphasizes the need for contact tracing and screening for early diagnosis of child leprosy to prevent complications like leprosy reactions which are the risk factors for disability.