Faria Hasanzadeh Haghighi; Hadi Farsiani; Mina Mostafavi; Mohammadhassan Aelami
Abstract
Meningitis is a clinical syndrome that occurs for a variety of reasons such as bacterial infections. Acute bacterial meningitis can occur at any age, and is a leading cause of mortality worldwide. Streptococcus pneumonia is a bacterial meningitis that can lead to pneumococcal meningitis, especially in ...
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Meningitis is a clinical syndrome that occurs for a variety of reasons such as bacterial infections. Acute bacterial meningitis can occur at any age, and is a leading cause of mortality worldwide. Streptococcus pneumonia is a bacterial meningitis that can lead to pneumococcal meningitis, especially in children. In recent decades, the percentage of pneumococcal strains resistant to penicillin and cephalosporins isolated from children has increased. This has made vancomycin the first empirical antibiotic therapy for children with suspected bacterial meningitis.In this report, we introduce a 13-month-old child who was brought to the emergency department of Akbar Children’s Hospital, Mashhad (a city in northeastern Iran) with complaints of high-grade fever and drowsiness. Meningitis was diagnosed via sampling of cerebrospinal fluid, and the culture indicated S. pneumonia that was non-sensitive to vancomycin. The e-test and microdilution have been approved to determine the minimum inhibitory concentration (MIC) of vancomycin; however, the e-test is a more straightforward method and the error probability is less while providing similar results to microdilution. Also, both methods can predict vancomycin tolerance or reduce sensitivity to vancomycin. Results of the e-test indicate MIC=2.
Kobra Salimiyan Rizi; Hadi Farsiani
Abstract
The formation of the massive deletion of genes called “black holes,” which are detrimental to a pathogenic lifestyle, provides a bacterial evolutionary route that permits a pathogen to augment virulence and host-adaptability. For example, cadaverine substrate has inhibitory effects on the ...
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The formation of the massive deletion of genes called “black holes,” which are detrimental to a pathogenic lifestyle, provides a bacterial evolutionary route that permits a pathogen to augment virulence and host-adaptability. For example, cadaverine substrate has inhibitory effects on the enterotoxin activity of the Shigella species. Therefore, the encoding gene of the lysine decarboxylase enzyme (CadA gene) as an anti-virulence gene is deleted from the genome of the Shigella. This and other similar cases in bacteria can be used for antitoxin therapy. Hence, identification of the role of black holes in the pathogenic evolution of bacteria output could possibly lead to novel treatments of infectious diseases in human beings. Here, we reviewed different types of pathoadaptation mutations among pathogens. Cases of black holes among the important human bacterial pathogens included Shigella, Rickettsiae, Mycobacterium leprae, Burkholderia, Bordetella, and Chlamydia. We found that the most prevalent pathoadaptive pathway among bacteria was the gene inactivation or deletion route.
Kobra Salimiyan rizi; Hadi Farsiani; Mohammad Momen Ghalibaf
Abstract
Today, human bloodstream infections (BSIs) are recognized as a major cause of morbidity and mortality worldwide. The bacteria, responsible for bacteremia, are usually identified in diagnostic clinical laboratories, using blood cultures. True bacteremia is defined as a positive blood culture (>15 CFU/mL), ...
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Today, human bloodstream infections (BSIs) are recognized as a major cause of morbidity and mortality worldwide. The bacteria, responsible for bacteremia, are usually identified in diagnostic clinical laboratories, using blood cultures. True bacteremia is defined as a positive blood culture (>15 CFU/mL), with signs and symptoms of infection (e.g., fever and chills). A wide range of bacteria can cause true bacteremia and some bacterial isolates from BSIs may be responsible for contamination. Gram-positive bacilli, such as Bacillus species, and coryneform bacteria are suspected sources of contamination in blood cultures. However, in certain patients, such as immunocompromised patients and intravenous drug users, gram-positive bacilli can act as a true pathogen. Therefore, it is important to know when gram positive bacilli act as a true pathogen and when they act as contamination. So, the rapidly diagnosis of true pathogens and appropriate treatment play a very important role in controlling infection with these bacteria. Effective measures are especially important in patients with an underlying disease or an immunocompromised status. In this article, we reviewed the literature on common Gram-positive rod-shaped bacteria, which were isolated from blood cultures and were suspected to be true pathogens or contaminants.
Kobra Salimiyan rizi; Kiarash Ghazvini; Hadi Farsiani
Abstract
Enterobacter spp. is a gram-negative environmental bacterium, which belongs to the Enterobacteriaceae family and is found in water, sewage, soil, and plants. These bacteria are common among humans and animals, and the most frequently isolated species is Enterobacter cloacae. The species of this genus ...
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Enterobacter spp. is a gram-negative environmental bacterium, which belongs to the Enterobacteriaceae family and is found in water, sewage, soil, and plants. These bacteria are common among humans and animals, and the most frequently isolated species is Enterobacter cloacae. The species of this genus are often opportunistic pathogens with expanding significance in nosocomial infections, particularly in neonates, immunocompromised patients in intensive care units, emergency sections, skin and soft tissue infection wards, and urology wards. With the unexpected and rapid increase in antibiotic resistance in various bacterial species, there has been a new alarm for the health of the human community. Enterobacter species cause pneumonitis, bacteremia, post-neurosurgical meningitis, neonatal meningitis, skin and soft tissue infections, and urinary tract infections. Some of the main risk factors for the occurrence and dissemination of Enterobacter spp. infections are poor hand hygiene, crowding, low birth weight, premature birth, intubation of patients, prolonged hospital stay, contaminated infant formula, intravenous feeding, use of extended-spectrum antibiotics and use of intravenous catheters.
Kobra Salimiyan Rizi; Hadi Farsiani; Saeid Amel Jamehdar; Mahboubeh Mohammadzadeh
Abstract
Elizabethkingia meningoseptica is an emerging nosocomial gram-negative, rod-shaped pathogen in patients with underlying diseases. This bacterium is also considered to be a major pathogen in hospitalized patients. Some of the main risk factors for E. meningosepticum infections include immunosuppression ...
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Elizabethkingia meningoseptica is an emerging nosocomial gram-negative, rod-shaped pathogen in patients with underlying diseases. This bacterium is also considered to be a major pathogen in hospitalized patients. Some of the main risk factors for E. meningosepticum infections include immunosuppression (e.g., end-stage hepatic and renal diseases) and prematurity in neonates. Furthermore, E. meningosepticum could cause pneumonia, endocarditis, and bacteremia in adults. The uncommon resistance pattern of this bacterium, as well as its intrinsic resistance to colistin, makes the treatment of the associated infections challenging unless the susceptibility patterns are available. In this article, we have presented the first case of pulmonary coinfection with multidrug-resistant (MDR) Acinetobacter spp. and E. meningoseptica in Iran. A 20-year-old female patient was admitted to our hospital with tetralogy of fallot as an underlying disease since childhood. The patient underwent cardiac surgery. On the third postoperative day (POD), the patient developed lung infection and left-lung collapse. Antibiotic therapy was initiated for MDR Acinetobacter spp. obtained from her primary culture of tracheal discharges. When fever persisted in the patient, the secondary culture of her tracheal discharges was observed to be positive for E. meningoseptica. In this case report, no clinical correlations were observed between the E. meningoseptica isolated from respiratory secretions and the primary respiratory infection, suggesting that E. meningoseptica is an indicator of severe underlying diseases rather than an actual pathogen.
Kobra Salimiyan Rizi; Hadi Farsiani; Kiarash Ghazvini; Masoud Youssefi
Abstract
Rothia dentocariosa (R. dentocariosa) is a gram-positive bacterium, which is a microorganism that normally resides in the mouth and respiratory tract. R. dentocariosa is known to involve in dental plaques and periodontal diseases. However, it is considered an organism with low pathogenicity and is associated ...
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Rothia dentocariosa (R. dentocariosa) is a gram-positive bacterium, which is a microorganism that normally resides in the mouth and respiratory tract. R. dentocariosa is known to involve in dental plaques and periodontal diseases. However, it is considered an organism with low pathogenicity and is associated with opportunistic infections. Originally thought not to be pathogenic in humans, R. dentocariosa was first described to cause infections in a 19-year-old female with periappendiceal abscess in 1975. The most prevalent human infections caused by R. dentocariosa include infective endocarditis, bacteremia, endophthalmitis, corneal ulcer, septic arthritis, pneumonia, and peritonitis associated with continuous ambulatory peritoneal dialysis. Three main factors have been reported to increase the risk of the cardiac and extra-cardiac infections caused by R. dentocariosa, including immunocompromised conditions, pre-existing cardiac disorders, and poor oral hygiene. Peritoneal dialysis (PD) may induce peritonitis presumably due to hematogenous spread from gingival or periodontal sources. This case study aimed to describe a former PD patient presenting with peritonitis. Oral hygiene is a basic principle in PD patients for the prevention of peritonitis. It is speculated that our patient might have had an occult oral source of R. dentocariosa.
Mohsen Karbalaei Zadeh Babaki; Mahdis Ghavidel; Hadi Farsiani; Kiarash Ghazvini
Abstract
Bacillus anthracis is an aerobic, gram-positive, and spore-forming Bacillus species. The most common form of anthrax infection is the cutaneous form. The infection usually develops several days after exposure to products of infected animals and manifest as black sore with severe swelling on the skin.A ...
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Bacillus anthracis is an aerobic, gram-positive, and spore-forming Bacillus species. The most common form of anthrax infection is the cutaneous form. The infection usually develops several days after exposure to products of infected animals and manifest as black sore with severe swelling on the skin.A 52-year-old female with a black and swollen lesion on her index finger presented to Ghaem Hospital, Mashhad, Iran, in October 2015. Biopsy and swab culture were performed immediately. Cutaneous anthrax was characterized by microscopic examination of B. anthracis spore using Gram staining. The patient was then treated with antibiotics after diagnosis.According to the reports of Provincial Health Center of Khorasan Razavi, northeast of Iran, no cases of anthrax have been reported in humans since 2013. There were neither occupational risk factors, nor any routine predisposing factors for acquiring anthrax in this woman. Although this patient is the first case reported with cutaneous anthrax since the past three years, two cases of sheep anthrax have been reported in Khorasan Razavi Province during 2013-2015. This patient had a history of contact with the skull of a slaughtered sheep. The patient was treated after making correct and rapid diagnosis and sufficient antibiotic therapy.