The changing panorama of bacterial enteric infections

Yield of Emergency Department Stool Culture Tests Among Children With Acute Gastroenteritis in Israel

Previous studies have attempted to predict a positive stool culture in pediatric patients with acute gastroenteritis (AGE), but most of them are either from developing countries or are outdated. In all, 276 patients with AGE and 560 control patients were analyzed for differences in clinical factors including the presence of fever, highest recorded temperature, bloody diarrhea, number of bowel movements in 24 hours prior to presentation, and the presence of seizures, as well as laboratory parameters including leukocyte count and C-reactive protein (CRP). Positive stool sample rate was 13.7%. The most common bacterial pathogen was Campylobacter jejuni. Bacterial AGE was significantly associated with fever >37.9°C, bloody diarrhea, higher stool passing frequency, seizures, and CRP levels. For pediatric patients who present to the emergency department with AGE and present without bloody diarrhea, fever, frequent stool passing, or seizures, a stool culture test is of poor yield and may not be necessary.

Bacterial resistance to commonly prescribed antibiotics was rare among children hospitalised for clinical dysentery

AIM

Temporal changes in common pathogens that cause clinical dysentery have been described in Europe. We aimed to describe the distribution of pathogens and their antibiotic resistance in hospitalised Israeli children.

METHODS

This study retrospectively studied children hospitalised for clinical dysentery, with or without a positive stool culture, from 1 January 2016 to 31 December 2019.

RESULTS

We diagnosed 137 patients (65% males), with clinical dysentery at a median age of 3.7 (interquartile range 1.5-8.2) years. Stools were cultured in 135 patients (99%), and the results were positive in 101 (76%). These comprised Campylobacter (44%), Shigella sonnei (27%), non-typhoid Salmonella (18%) and enteropathogenic Escherichia coli (12%). Only one of the 44 Campylobacter cultures was resistant to erythromycin and one of the 12 enteropathogenic Escherichia coli cultures was resistant to ceftriaxone. None of the Salmonella and Shigella cultures were resistant to ceftriaxone or erythromycin. We did not find any pathogens that were associated with a typical clinical presentation or laboratory results on admission.

CONCLUSION

The most common pathogen was Campylobacter, in line with recent European trends. Bacterial resistance for commonly prescribed antibiotics was rare, and these findings support the current European recommendations.

Intestinal Infections Among Febrile Hospitalized Patients in the Republic of Armenia: A Retrospective Chart Review

In the past, several enteric outbreaks in 1996, 1998, 1999, and 2003 caused by Salmonella typhi, a Gram-negative bacterium, have occurred in Armenia. This study describes the demographic, epidemiological, and clinical characteristics of febrile hospitalized patients with intestinal infections in Armenia. Using a chart review study design, medical data from adult patients who were hospitalized at the Nork hospital during 2010–2012 were reviewed. A total of 600 medical charts were reviewed. Of these, 51 % were diagnosed with intestinal infections. Among these patients, 59 % had an intestinal infection of known etiology, with three main pathogens identified: Salmonella sp. (32 %), Shigella sp. (32 %), and Staphylococcus aureus (18 %). After controlling for the calendar year, age in years, and gender, patients detected with Salmonella sp. were more likely to reported the presence of a family member with similar signs or symptoms [odds ratio (OR) 9.0; 95 % CI 2.4–33.7] and the lack of a water tap at home (OR 3.9; 95 % CI 1.7–9.5). Evidence indicates that Salmonella sp., Shigella sp., and S. aureus as the most common etiologies reported among febrile hospitalized patients. A high percentage of patients had intestinal infections of unknown etiology; thus, improvement in laboratory capacity (enabling more advanced tests, such as polymerase chain reaction) would increase the identification of the enteropathogens causing disease in Armenia.

Characterization of new Myoviridae bacteriophage WZ1 against multi-drug resistant (MDR) Shigella dysenteriae

Shigella dysenteriae is a normal inhabitant of the human gastrointestinal tract, but sometimes it causes severe infection known as shigellosis (bacillary dysentery). Bacteriophages are considered very safe and effective agents for controlling bacterial infections and contaminations. In this study, we describe the isolation and characterization of bacteriophage WZ1, isolated from waste water which inhibits the growth of S. dysenteriae. Phage WZ1 showed maximum stability at 37 °C and was stable up to 65 °C but was totally inactive at 70 °C. The pH stability increased from low to high and was totally inactive at pH 3 while maximum stability was observed at optimal pH 7. Phage WZ1 adsorption rate to the host bacterium was significantly enhanced by the addition of CaCl2 . It has a latent time and burst time of 24 min and about 430 virions/cell, respectively. Transmission electron microscopy of phage WZ1 revealed a head width of 10 ± 0.5 nm and length of 10 ± 0.2 nm with a contractile tail of 128 ± 25 nm long and 21 ± 0.5 nm wide and belongs to family Myoviridae of order Caudovirales. Twelve structural proteins ranging from 22 to 150 kDa were detected by Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis (SDS-PAGE). The genome was found to be double stranded DNA with an approximate size of 38 kb. It has a very good reduction potential for S. dysenteriae by lowering abruptly the optical density of the planktonic S. dysenteriae culture. Phage WZ1 is a very promising candidate for phage therapy and other applications such as phage typing.

Increased incidence of Campylobacter spp. infection and high rates among children, Israel

During 1999–2010, the annual incidence of Campylobacter spp. infection in Israel increased from 31.04 to 90.99 cases/100,000 population, a yearly increase of 10.24%. Children <2 years of age were disproportionally affected; incidence in this age group (356.12 cases/100,000 population) was >26-fold higher than for the 30–<50 age group.

Epidemiological trends and patterns of antimicrobial resistance of Shigella spp. isolated from stool cultures in two different populations in Southern Israel

Southern Israel is inhabited by Bedouins, living in conditions similar to developing countries and Jews, living in conditions similar to developed countries. We determined the epidemiology of Shigella spp. in these populations. We retrospectively reviewed Shigella spp. stool isolations between 2005-2009. Overall, 3295 isolates were analyzed. S. sonnei was isolated in 2057/3295 (62.4%) and S. flexneri in 1058 (32.1%). S. sonnei was isolated in 1567/1707 (91.8%) from Jewish patients and S. flexneri in 931/1542 (60.4%) from Bedouin patients. Ampicillin resistance increased linearly from 217/373 (58.2%) in 2005 to 186/256 (72.7%) in 2009, (P < 0.001). Trimethoprim-sulfamethoxazole resistance decreased linearly from 328/373 (87.9%) in 2005 to 133/256 (51.9%) in 2009 (P < 0.001). Higher resistance of Shigella spp. to ampicilin and trimethoprim-sulfamethoxazole were found in Jewish patients: 1527/1706 (89.5%) versus 977/1542 (63.4%) (P < 0.0001), 1635/1706 (95.8%) versus 1026/1542 (66.5%) (P < 0.0001). The epidemiology of Shigella spp. infections can differ in populations residing in the same geographical area.

Biennial hyperepidemic shigellosis in an observant Jewish community

We aimed to study patterns of shigellosis in a large observant Jewish community in Israel and to describe local interventions during outbreaks. Surveillance data from the Ministry of Health were used to calculate incidence rates in 1998-2006, both in the city of Bene Beraq and the Tel Aviv district. Information on isolates was collected from the bacteriological laboratory of a community hospital. Public notices and educational conferences conveyed a message to increase personal hygiene and keep ill children at home. During a 9-year period, a clear biennial pattern of outbreaks was noticed. Annual incidence rates ranged between 18 and 353/100,000 population. Shigellosis outbreaks tended to occur in the winter and were attributed to clonally related Shigella sonnei strains. Outbreaks in Bene Beraq preceded those in the other cities of Tel Aviv district, suggesting propagation of disease. In this population with highly endemic as well as superimposed outbreaks of shigellosis, short-term interventions had no lasting effect on prevention; future studies should focus on community-based programmes to avoid anticipated outbreaks.