Hamid Heidari

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Verified

Hamid verified their affiliation via an institutional email.

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• Doctor of Philosophy
• Professor (Assistant) at Shahid Sadoughi University of Medical Sciences and Health Services

Background Rising methicillin-resistant Staphylococcus aureus (MRSA) poses a global health threat, contributing to serious infections with high mortality rates. Integrons are recognized as significant genetic elements in disseminating multidrug-resistant (MDR) strains. This study focuses on assessing the prevalence of integron classes 1, 2, and 3 i...

Background Meningitis is highly prevalent in infant because their immune system is immature and they have less resistance to diseases. Among bacterial agents, Escherichia coli is recognized as one of the most important causes of meningitis in infants. Case presentation Herein, we report a case of late-onset meningitis, caused by E. coli (Patient:1...

Antimicrobial resistance is a significant global public health issue, and the dissemination of antibiotic resistance in Gram-positive bacterial pathogens has significantly increased morbidity, mortality rates, and healthcare costs. Among them, Staphylococcus, especially methicillin-resistant Staphylococcus aureus (MRSA), causes a wide range of dise...

Background and Aims Emergence of multidrug resistance in non‐fermenting Gram‐negative bacilli is a threat to public health. Combination therapy is a strategy for the treatment of antibiotic‐resistant infections. Methods In this cross‐sectional study, a total of 63 nonduplicate clinical isolates of Acinetobacter baumannii and Pseudomonas aeruginosa...

Drug resistance among Mycobacterium tuberculosis (MTB) strains is a growing concern in developing countries. We conducted a comprehensive search for relevant studies in Iran on PubMed, Scopus, and Embase until June 12, 2020. Our study focused on determining the prevalence of antibiotic resistance in MTB isolates, with subgroup analyses based on yea...

Background Non-tuberculous mycobacteria (NTM) infections have been continuously increasing as major concerns of public health in Iran. Because innate resistance of NTM species, the treatment of these infections is difficult task, but until now resistance pattern of NTM and suitable regimens are not determined. Methods We systematically searched th...

Background: Disinfectants and antiseptics inhibit the dissemination of pathogenic organisms in hospitals but often cause disinfectant-resistant microorganisms, an important factor for nosocomial infection. This study aimed to evaluate the correlation between qacΔE efflux pump gene and its resistance to disinfectants among Escherichia coli clinical...

While trimethoprim-sulfamethoxazole (TMP-SMX) is the first-line therapy of Stenotrophomonas maltophilia infections, colistin is one of the therapeutic options in cases of allergy or resistance to TMP-SMX. However, understanding the global status of resistance to colistin amongst S. maltophilia isolates could be helpful for appropriate antibiotic pr...

Pyrazinamide (PZA) is an essential first-line tuberculosis drug for its unique mechanism of action active against multidrug-resistant-TB (MDR-TB). Thus, the aim of updated meta-analysis was to estimate the PZA weighted pooled resistance (WPR) rate in M. tuberculosis isolates based on publication date and WHO regions. We systematically searched the...

Objectives: Eye infections can be caused by several microorganisms and the most common causative bacterial agents are staphylococci, streptococci, and Pseudomonas aeruginosa. This study aimed to estimate the prevalence of Staphylococcus aureus, Staphylococcus epidermidis, viridans group streptococci, and P. aeruginosa as the cause of ocular infecti...

Background Burn injuries result in disruption of the skin barrier against opportunistic infections. Pseudomonas aeruginosa is one of the main infectious agents colonizing burn wounds and making severe infections. Biofilm production and other virulence factors along with antibiotic resistance limit appropriate treatment options and time. Materials...

Nocardial brain abscess is usually associated with immunodeficiency, but can sometimes emerge in healthy individuals. This infection can be acquired through inhalation or direct inoculation of the bacteria, followed by dissemination to various organs, including the brain, through blood circulation. Mortality rate due to nocardial cerebral abscess i...

Background: Enterococci are considered as important causative pathogens of a variety of community and hospital-acquired infections. Due to the development of multidrug resistant (MDR) enterococci and the emergence of strains possessing high-level resistance to antimicrobial agents, treatment of their infections has been more complicated. In additi...

Introduction: Mycobacterium tuberculosis (MTB), the causative agent of tuberculosis (TB), is a significant global public health threat. Besides extensive multidrug resistance, MTB possesses several properties for long-term viability in the host as well as stress adaptation and resistance in harsh conditions. The role of toxin-antitoxin (TA) system...

Enterococci have been considered as one of the most common causes of nosocomial infections. The spread of antibiotic resistance has posed a serious challenge to treating the enterococcal infections. High-level aminoglycosides resistance leads to failure in the synergistic combination therapy. This study aimed to estimate the prevalence of high-lev...

Background Multidrug resistance among ESBL producing isolates has limited the administration of proper antibiotics. It is therefore important to monitor the resistance patterns of Klebsiella pneumoniae isolates and provide infection control strategies to prevent nosocomial outbreaks. This study was aimed to determine antimicrobial resistance patter...

Background: Clostridioides difficile a Gram-positive, obliged anaerobic, rod-shaped spore-former bacterium, causes a wide spectrum of diseases, ranging from mild, self-limiting diarrhoea to serious diarrhea. Chitosan, a natural polysaccharide, is largely known for its activity against a wide range of microorganisms. Chitosan, in the form of nanofi...

Objective: The present study aimed to determine in vitro activity of colistin and other agents against drug-resistant isolates of Pseudomonas aeruginosa and Acinetobacter baumannii. Results: This in vitro study performed on a collection of non-fermenting Gram-negative bacilli (NFB) consist of 18 A. baumannii and 21 P. aeruginosa isolates. Non-du...

Objectives: Drug resistance among gram-negative bacteria is a worldwide challenge. Due to the importance of drug-resistant Klebsiella pneumoniae and Escherichia coli strains in hospital-acquired infections, we aimed to determine the phenotypic and genotypic characteristics of ESBL-, AmpC-, and carbapenemase-producing isolates obtained from hospita...

Objectives: Stenotrophomonas maltophilia has emerged as an important opportunistic nosocomial pathogen due to its intrinsic and acquired resistance to a wide range of antimicrobial agents. The present study aimed to investigate the occurrence of antibiotic resistance and resistance mechanisms among clinical isolates of S. maltophilia from Iranian...

Objectives: Clostridioides (Clostridium)difficile infection as a healthcare-associated infection can cause life-threatening infectious diarrhea in hospitalized patients. The aim of this study was to investigate the toxin profiles and antimicrobial resistance patterns of C. difficile isolates obtained from hospitalized patients in Shiraz, Iran. Ma...

Background: Quinolones are a family of synthetic antimicrobial agents with a broad antibacterial activity commonly used as a suitable therapy in patients with urinary tract infection (UTI). In the present study, we aimed to evaluate the prevalence of quinolones resistance and the presence of plasmid-mediated quinolone resistance (PMQR) genes among...

Clostridium difficile (recently Clostridioides difficile) is a leading cause of hospital- and antimicrobial-associated diarrhea (AAD). The present study was carried out to investigate the prevalence of toxigenic C. difficile, antibiotic resistance and its associated risk factors in Iranian hospitalized patients. This cross-sectional study was condu...

Multiple drug-resistant enterococci are major cause of healthcare-associated infections due to their antibiotic resistance traits. Among them, Enterococcus faecalis is an important opportunistic pathogen causing various hospital-acquired infections. A total of 53 E. faecalis isolates were obtained from various infections. They were identified by ph...

Summary Introduction Infectious keratitis is a serious ocular infection that can lead to severe visual impairment and blindness. Bacterial pathogens are responsible for nearly half of infectious keratitis cases. This study was performed to determine the virulence factors, antimicrobial resistance patterns, and biofilm formation ability of Pseudomon...

Background Neisseria gonorrhea and Treponema pallidum as an obligate human pathogen are two common causes of sexually transmitted diseases (STDs). The present study aimed to determine the prevalence of N. gonorrhoeae and T. pallidum among human immunodeficiency virus (HIV) patients in the southwest Iran. Methods This retrospective study was perfor...

Background: Recently, nanotechnology has been demonstrated to be a promising application to overcome the problem of antibiotic resistance. In the present study, we aimed to determine the antibacterial activity of copper oxide nanoparticles (CuO NPs) on several multiple-drug resistant (MDR) uropathogenic strains. Methods: This in vitro case-control...

Background: Staphylococcus aureus is a common cause of nosocomial infections that leads to broad spectrum of diseases. Increasing antibiotic resistance among S. aureus strains, particularly methicillin-resistant S. aureus (MRSA) is a serious concern. In addition, the emergence of antiseptics resistance in MRSA helps organism to easily persist and s...

Background: Mycobacterium tuberculosis as an intracellular pathogen causes tuberculosis (TB). Due to the long time required for treatment, hepatotoxicity of drugs and also emergence of multidrug-resistant (MDR) and extremely drug resistant (XDR) strains, TB is currently a major public health problem. Some medicinal plants possess remarkable activi...

Acinetobacter baumannii is an important pathogen that associated with several hospital-acquired infections. It has the ability to colonize in hospital setting and infections due to A. baumannii can be transferred by direct or indirect contact between patients. Characterization of the local molecular epidemiology is required for control the spread o...

Objectives: Urinary tract infections (UTIs) are one of the most prevalent infectious diseases and can lead to a high rate of morbidity and mortality. The emergence of multipledrug resistant strains, particularly extended-spectrum beta-lactamases (ESBLs) producing strains, has become a global healthcare concern. Our study sought to investigate the a...

OBJECTIVE To determinate the seroprevalence of Toxoplasma gondii among patients with HIV, and other probable risk factors associated with this situation, including demographic and clinical factors. METHOD This retrospective study was carried out on 246 HIV positive patients at the Shiraz HIV/AIDS research center, in Southwest Iran, in the two years...

Abstract: Background: Today considerable number of drugs are produced from plants. Several plants with antibacterial and healing applications are used in medicine such as Roman chamomile (Chamaemelum nobile L.). Wound infection is one of the most prevalent infections among infectious diseases around the world. Due to ap-pearance of drug resistance,...

The emergence of multiple drug-resistant (MDR) Acinetobacter baumannii strains has become a global problem. This study aimed to evaluate the occurrence of antibiotic resistance and to investigate the presence of antibiotic resistance determinants among A. baumannii isolates obtained from hospitalized patients in Iran. This cross-sectional study was...

Infections due to Elizabethkingia meningoseptica, a Gram-negative oxidative bacterium are frequently founded in neonatal and immunocompromised individuals. The notable characteristic of this organism is its multi-drug resistance to common antibiotics used for infections caused by Gram-negative bacteria. We report a rare case of complicated pericard...

Background: Staphylococcus aureus is one of the most common causes of nosocomial infections that cause a broad spectrum of diseases. Increasing antibiotic resistance among S. aureus isolates is a serious concern in the treatment and control of staphylococcal infections. The knowledge of S. aureus prevalence and the current antimicrobial resistance...

Objectives: The aim of the study was to investigate the linezolid activity against clinical Gram-positive cocci with advanced antimicrobial drug resistance. Methods: A collection of methicillin resistant Staphylococcus aureus (MRSA), vancomycin resistant enterococci (VRE), penicillin non-susceptible Streptococcus pneumoniae (PNSP), and group B s...

Clinical mastitis caused by Enterobacteriaceae accounts for significant economic loss in dairy herds. One of the important pathogens that causes mastitis is Shiga toxinproducing Escherichia coli (STEC). Moreover, mastitis caused by STEC can be considered as a source of transmission of STEC strains to humans through unpasteurized milk. The aim of th...

Background Recently, Stenotrophomonas maltophilia has increasingly been reported as an important nosocomial opportunistic pathogen. Limited therapeutic options of S. maltophilia infections demand early identification and knowledge about the probable risk factors for controlling its spread. Study design The present study aimed to investigate the ris...

Background: Strains belonging to Enterobacter genus are important opportunistic nosocomial pathogens. Resistance to broad-spectrum antibiotics often complicates the treatment of Enterobacter infections. Aim and Objectives: The present study was aimed to determine the frequency and antibiotic resistance patterns of Enterobacter spp. obtained from a...

Background: Over the past two decades, enterococci have emerged as an important agent responsible for hospital acquired infection. Several virulence factors contribute to the adherence, colonization, evasion of the host immune response, and pathogenicity and severity of the infection. Enterococcus faecalis is the most common and virulent species c...

Background: Infection is a serious problem in medicine and appropriate antibiotic therapy is very important. Because of broad spectrum activity and low toxicity of β-lactam antibiotics, they are the most commonly used drugs. But, bacterial resistance to β-lactam antibiotics, has been considered as the global healthcare concern. The aim of study was...

The growing frequency of antibiotic resistances is now a universal problem. Increasing resistance to new generations of β-lactam and quinolone antibiotics in multidrug- resistant Enterobacteriaceae isolates is considered an emergency health issue worldwide. The aim of this study was to evaluate plasmid-mediated quinolone resistance genes in ESBL-pr...

Background: Infections caused by antimicrobial-resistant bacteria are associated with increased mortality and health care costs. Enterococci have been recognized as a clinically important pathogen in hospitalized patients. Vancomycin-resistant enterococci (VRE) infections cause significant morbidity and mortality among patients undergoing transplan...

Background: Escherichia coli, known as a clinically significant bacteria, can cause a wide range of infections, including urinary tract infections (UTIs), blood stream infections (BSIs), and can frequently be isolated from various clinical specimens. Evaluation of antimicrobial resistant pattern is a necessary action, especially about such bacteria...

Background: Salmonella enterica serovar Typhimurium (S. Typhimurium) causes gastroenteritis in humans and paratyphoid disease in some animals. Given the emergence of antibiotic resistance, vaccines are more effective than chemotherapy in disease control. Objectives: The aim of this experimental study was to evaluate the immunogenicity of diphthe...

Background: The human immunodeficiency virus (HIV) is one of the most life- threatening human infections. The advent of highly active antiretroviral therapy (HAART) has dramatically changed the course of HIV infection and patients' quality of life. In addition to the benefits, HAART can have numerous side effects and toxicities. Therefore, we aime...

Background: Klebsiella pneumoniae is among the most frequently recovered etiologic agents from nosocomial infections. This opportunistic pathogen can generate a thick layer of biofilm as one of its important virulence factors, enabling the bacteria to attach to living or abiotic surfaces, which contributes to drug resistance. Objectives: The resist...

The enterococci are emerging as a significant cause of hospital acquired infections. The pathogenesis of enterococci is attributed to the production of virulence factors and resistance to antibiotics. The purpose of the study was to assess the prevalence of genes encoding virulence factor, antimicrobial resistance determinant and molecular characte...

Chamomile ( Chamaemelum nobile ) is widely used throughout the world, and has anti-inflammatory, deodorant, bacteriostatic, antimicrobial, carminative, sedative, antiseptic, anti-catarrhal, and spasmolytic properties. Because of the increasing incidence of drug-resistant bacteria, the development of natural antibacterial sources such as medical her...

Background: Gastroenteritis is a remarkable hygiene problem worldwide. Bacteria and parasites can cause gastroenteritis-associated disorders. Objectives: The aims of study were to survey the most common cause of gastroenteritis in patients referred to Imam Khomeini Hospital of Ilam, Iran. Patients and Methods: This descriptive-analytical study wa...

Diarrhea is one of the remarkable hygiene problems in the world. Despite reducing the diarrheal mortality rates for 3 million children per year through Oral Rehydration Therapy (ORT), mortality reduction among patients is still substantial. Objectives: The aim of this study is, detection of bacterial and parasitic agents isolated from diarrheal chi...

Background: Helicobacter pylori is a common cause of chronic infection in human beings. The infection has universal prevalence and contracts all age groups. Probably, these bacteria are the cause of the most common chronic bacterial infection in man and have infected approximately half of the world population. The urease of these bacteria degrades...