First report of Salmonella enterica serotype panama meningitis associated with consumption of contaminated breast milk by a neonate

Comparison of Phenotype and Genotype Virulence and Antimicrobial Factors of Salmonella Typhimurium Isolated from Human Milk

Salmonella is a common foodborne infection. Many serovars belonging to Salmonella enterica subsp. enterica are present in the gut of various animal species. They can cause infection in human infants via breast milk or cross-contamination with powdered milk. In the present study, Salmonella BO was isolated from human milk in accordance with ISO 6579-1:2017 standards and sequenced using whole-genome sequencing (WGS), followed by serosequencing and genotyping. The results also allowed its pathogenicity to be predicted. The WGS results were compared with the bacterial phenotype. The isolated strain was found to be Salmonella enterica subsp. enterica serovar Typhimurium 4:i:1,2_69M (S. Typhimurium 69M); it showed a very close similarity to S. enterica subsp. enterica serovar Typhimurium LT2. Bioinformatics sequence analysis detected eleven SPIs (SPI-1, SPI-2, SPI-3, SPI-4, SPI-5, SPI-9, SPI-12, SPI-13, SPI-14, C63PI, CS54_island). Significant changes in gene sequences were noted, causing frameshift mutations in yeiG, rfbP, fumA, yeaL, ybeU (insertion) and lpfD, avrA, ratB, yacH (deletion). The sequences of several proteins were significantly different from those coded in the reference genome; their three-dimensional structure was predicted and compared with reference proteins. Our findings indicate the presence of a number of antimicrobial resistance genes that do not directly imply an antibiotic resistance phenotype.

Human Milk Expression, Storage, and Transport by Women Whose Infants Are Inpatients at a Tertiary Neonatal Unit in Melbourne, Australia: An Exploratory Study

BACKGROUND

Expression and storage of mothers' own milk at home and its transportation to hospital neonatal units are a common practice worldwide when newborns are inpatients. Studies assessing adherence to hospital protocols and guidelines for this are not widely published.

PURPOSE

To explore the advice received and practices followed by mothers when expressing, storing, and transporting their milk from home to the hospital, with a substudy exploring the factors related to temperature maintenance of refrigerated milk at recommended values.

METHODS

Cross-sectional descriptive study at the neonatal intensive care unit of Mercy Hospital for Women, Melbourne, Australia. Mothers who were discharged home after birth of the infant, but whose infant(s) remained in the neonatal unit for 7 days or more participated. All participants completed a self-administered questionnaire. In the substudy, home refrigerator temperature and surface temperature of milk on arrival to the hospital were recorded.

RESULTS

The questionnaire was completed by 100 mothers; 38 participated in the substudy. Median travel time from home to the hospital was 32 minutes (range, 2-135 minutes). Lactation consultants were the largest group providing information, with 44 participants (45%) identifying them as the primary information source. Knowledge about recommended refrigerator storage times for expressed milk was correct in 53 mothers (54%). Coolness of milk was better maintained when transported in an insulated food container than nonuse (surface temperature: mean 9.1°C vs 12.2°C; P = .007). Distance and travel duration were not correlated with temperature.

IMPLICATIONS FOR PRACTICE

More diligent monitoring of conditions under which mothers' own milk is transported to hospital is required, and the use of an insulated food container for refrigerated/frozen milk, even for a short duration, should be strongly recommended. Staff to be trained and better equipped to provide uniform, concise information on expressed human milk management to mothers.

IMPLICATIONS FOR RESEARCH

Further research to correlate factors associated with transporting human milk expressed at home and infant health outcome is needed.

Microbiological and genomic investigations of invasive Salmonella enterica serovar Panama from a large outbreak in Taiwan

BACKGROUND/PURPOSE

Salmonella Panama was considered an invasive non-typhoidal Salmonella (iNTS) serovar. Comprehensive clinical, microbiological, and genomic studies on S. Panama are scarce. We aimed to characterize the clinical and microbiological characteristics of S. Panama infection. Virulence mechanism of S. Panama and other iNTS serovars were also examined.

METHODS

Based on data from the longitudinal surveillance system for Salmonella deployed in Taiwan since 2004, a case-control study was undertaken to evaluate clinical characteristics of S. Panama infection during an outbreak in 2015-2016. Cellular experiments were conducted to compare pathogenicity of S. Panama and other iNTS with S. Typhimurium.

RESULTS

Most patients (41/44, 93.2%) infected by S. Panama were <5 years old (median, 1.3 years). The case-control study showed that 28 out of the 41 (68.3%) manifested as bacteremia, compared to S. Typhimurium (11.1%). Patients infected by S. Panama had longer durations of fever (P = 0.005) and hospitalization (P < 0.001). Genomic analyses split the isolates into three clades: two clones caused the outbreak, whereas another one accounted for the sporadic infections before 2015. Cellular experiments revealed that S. Panama and other iNTS serovars showed higher monolayer penetration and intracellular survival within macrophages, compared to S. Typhimurium.

CONCLUSION

This study confirmed that S. Panama is a clinically invasive serovar. Different iNTS serovars express common virulence phenotypes, but they may acquire invasiveness through distinct expression or combinations of virulence genes.

Salmonella enterica Serovar Panama, an Understudied Serovar Responsible for Extraintestinal Salmonellosis Worldwide

In recent years nontyphoidal Salmonella has emerged as one of the pathogens most frequently isolated from the bloodstream in humans. Only a small group of Salmonella serovars cause this systemic infection, known as invasive nontyphoidal salmonellosis. Here, we present a focused minireview on Salmonella enterica serovar Panama, a serovar responsible for invasive salmonellosis worldwide. S Panama has been linked with infection of extraintestinal sites in humans, causing septicemia, meningitis, and osteomyelitis. The clinical picture is often complicated by antimicrobial resistance and has been associated with a large repertoire of transmission vehicles, including human feces and breast milk. Nonhuman sources of S Panama involve reptiles and environmental reservoirs, as well as food animals, such as pigs. The tendency of S Panama to cause invasive disease may be linked to certain serovar-specific genetic factors.

Salmonella enterica Serotype Panama: An exceptionally virulent cause of illness in children?

Salmonella enterica serotype Panama accounts for <1% of all reported cases of Salmonellosis. Previous reports suggest that it may be unusually virulent in children. We report the case of a family, five of six of whom developed a diarrheal illness due to this organism following exposure during a trip to Costa Rica. Included among these patients were three children, all of whom developed clinical shock requiring aggressive fluid resuscitation, and all of whom ultimately recovered. DNA fingerprinting, using pulsed-field gel electrophoresis, demonstrated that all three children were infected with an identical strain of Salmonella. Moreover, this strain was unique among strains recovered in Nebraska. Clinicians should be aware of the propensity of Salmonella enterica serotype Panama to cause especially severe disease in children; laboratory personnel should be aware of the unique need for thiourea buffering when attempting to perform pulsed-field gel electrophoresis analysis on such strains.

Meningitis caused by Salmonella enterica serotype Panama in Brazil: first case reported

Salmonella infections usually occur as gastroenteritis that is generally self-limited. However, some serotypes of Salmonella can cause severe extra-intestinal infections, such as bacteremia and meningitis. Here, we report the first Salmonella Panama case of meningitis in 4-month-old male newborn in Brazil. The invasive strain isolated was susceptible to all antimicrobial agents tested. The genes agfA, fimA, invA, sfbA, phoP, and slyA were detected using polymerase chain reactions. These findings are relevant and physicians should be alert to the possibility of meningitis in newborns due to S. Panama, which can present a high rate of mortality or recurrence of infection.

Complete Genome and Methylome Sequences of Salmonella enterica subsp. enterica Serovar Panama (ATCC 7378) and Salmonella enterica subsp. enterica Serovar Sloterdijk (ATCC 15791)

Salmonella enterica spp. are pathogenic bacteria commonly associated with food-borne outbreaks in human and animals. Salmonella enterica spp. are characterized into more than 2,500 different serotypes, which makes epidemiological surveillance and outbreak control more difficult. In this report, we announce the first complete genome and methylome sequences from two Salmonella type strains associated with food-borne outbreaks, Salmonella enterica subsp. enterica serovar Panama (ATCC 7378) and Salmonella enterica subsp. enterica serovar Sloterdijk (ATCC 15791).

Salmonella meningitis: a report from National Hue Central Hospital, Vietnam

Four Vietnamese infants who survived infection with Salmonella meningitis are reported. A female infant who experienced relapse recovered without complications and another had neurological sequellae. The remaining 2 infants survived without complications. The initial treatment was chloramphenicol and ceftriaxone, whereas a change of antibiotics to imipenem and fluoroquinolone was required for 2 infants. Fluoroquinolone may be a treatment option in patients with Salmonella meningitis who experience complications even though the drug is contraindicated for the pediatric age group.

Microbial contamination of human milk purchased via the Internet

OBJECTIVE

To quantify microbial contamination of human milk purchased via the Internet as an indicator of disease risk to recipient infants.

METHODS

Cross-sectional sample of human milk purchased via a popular US milk-sharing Web site (2012). Individuals advertising milk were contacted to arrange purchase, and milk was shipped to a rented mailbox in Ohio. The Internet milk samples (n = 101) were compared with unpasteurized samples of milk donated to a milk bank (n = 20).

RESULTS

Most (74%) Internet milk samples were colonized with Gram-negative bacteria or had >10(4) colony-forming units/mL total aerobic count. They exhibited higher mean total aerobic, total Gram-negative, coliform, and Staphylococcus sp counts than milk bank samples. Growth of most species was positively associated with days in transit (total aerobic count [log10 colony-forming units/mL] β = 0.71 [95% confidence interval: 0.38-1.05]), and negatively associated with number of months since the milk was expressed (β = -0.36 [95% confidence interval: -0.55 to -0.16]), per simple linear regression. No samples were HIV type 1 RNA-positive; 21% of Internet samples were cytomegalovirus DNA-positive.

CONCLUSIONS

Human milk purchased via the Internet exhibited high overall bacterial growth and frequent contamination with pathogenic bacteria, reflecting poor collection, storage, or shipping practices. Infants consuming this milk are at risk for negative outcomes, particularly if born preterm or are medically compromised. Increased use of lactation support services may begin to address the milk supply gap for women who want to feed their child human milk but cannot meet his or her needs.

Recurrent meningitis due to Salmonella enteritidis: a case report from Kashmir India

Recurrent bacterial meningitis in children is potentially life-threatening and induces psychological trauma to the patients through repeated hospitalization. Here we report a case of recurrent meningitis in a one month old baby. The CSF and blood culture grew Salmonella enteritidis. Injection ciprofloxacin and ceftriaxone were given for 3 weeks. Baby became symptomatically better and was afebrile at discharge. Twenty eight days after discharge baby got readmitted with complaints of fever and refusal of feeds. Blood and CSF culture again showed growth of Salmonella enteritidis. Physicians should be educated about the possibility of recurrence which may occur days or even weeks after apparent successful antibiotic treatment.

Salmonella meningitis in a paediatric patient caused by Salmonella enterica serotype Houtenae

The authors report a case of a 6-week-old baby girl who was admitted to the paediatric ward due to a high fever for 2 days. The patient experienced three fits which took place while in the ward. A brain sonogram showed subdural heterogeneous collection consistent with focal empyema; however, no hydrocephalus or infarction was detected. An urgent Burr hole procedure was performed to remove the collected pus. Both blood and cerebrospinal fluid (CSF) culture grew Salmonella species which remain sensitive to some antibiotics. This strain was sent to the institute of medical research (IMR) for serotyping. The patient was treated with intravenous combination of ceftriaxone and ciprofloxacin for 3 weeks. One week later, IMR sent results that identified the strain as Salmonella enterica serotype Houtenae. Following antibiotic treatment, repeat ultrasound illustrated an improvement of the subdural empyema, and the gram stain of the CSF specimen failed to isolate bacteria.

Molecular cloning and characterization of clyA genes in various serotypes of Salmonella enterica

Cytolysin A (ClyA) is a pore-forming hemolytic protein encoded by the clyA gene. It has been identified in Salmonella enterica serovars Typhi and Paratyphi A. To identify and characterize the clyA genes in various Salmonella enterica strains, 21 different serotypes of strains isolated from clinical specimens were presently examined. Full-length clyA genes were found in S. enterica serovar Brandenburg, Indiana, Panama, and Schwarzengrund strains by polymerase chain reaction amplification. The ClyA proteins from these four strains showed >97% amino acid identity to that of S. enterica serovar Typhi. Although all four serovars expressed detectable levels of ClyA as determined by Western blot analysis, they did not show a strong hemolytic effect on blood agar, indicating that ClyA may not be efficiently expressed or secreted. Escherichia coli transformed with clyA genes from the four serovars enhanced production of ClyA proteins and hemolytic activities to a level similar to S. enterica serovar Typhi ClyA. The present results suggest that ClyA may play a role in the pathogenesis of S. enterica serovar Brandenburg, Indiana, Panama and Schwarzengrund.

Report of neonatal meningitis due to Salmonella enterica serotype Agona and review of breast milk-associated neonatal Salmonella infections

We present the first documented case of Salmonella enterica serotype Agona meningitis in a 6-day-old baby. S. enterica serotype Agona was isolated concurrently from infant cerebrospinal fluid and parental fecal samples, and Salmonella was isolated from breast milk. The role of breast milk in transmission of Salmonella enterica is discussed.